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I. INJURIES OF BONES

Contusions--Wounds--FRACTURES: Pathological; Traumatic; Varieties--Simple fractures--Compound fractures--Repair of fractures--Interference with repair--Gun-shot fractures--SEPARATION OF EPIPHYSES.

The injuries to which a bone is liable are Contusions, Open Wounds, and Fractures.

#Contusions of Bone# are almost of necessity associated with a similar injury of the overlying soft parts. The mildest degree consists in a bruising of the periosteum, which is raised from the bone by an effusion of blood, constituting a haematoma of the periosteum. This may be absorbed, or it may give place to a persistent thickening of the bone--traumatic node.

#Open Wounds of Bone# of the incised and contused varieties are usually produced by sabres, axes, butcher's knives, scythes, or circular saws. Punctured wounds are caused by bayonets, arrows, or other pointed instruments. They are all equivalent to compound, incomplete fractures.

FRACTURES

A fracture may be defined as a sudden solution in the continuity of a bone.

PATHOLOGICAL FRACTURES

A pathological fracture has as its primary cause some diseased state of the bone, which permits of its giving way on the application of a force which would be insufficient to break a healthy bone. It cannot be too strongly emphasised that when a bone is found to have been broken by a slight degree of violence, the presence of some pathological condition should be suspected, and a careful examination made with the X-rays and by other means, before arriving at a conclusion as to the cause of the fracture. Many cases are on record in which such an accident has first drawn attention to the presence of a new-growth, or other serious lesion in the bone. The following conditions, which are more fully described with diseases of bone, may be mentioned as the causes of pathological fractures.

Atrophy of bone may proceed to such an extent in old people, or in those who for long periods have been bed-ridden, that slight violence suffices to determine a fracture. This most frequently occurs in the neck of the femur in old women, the mere catching of the foot in the bedclothes while the patient is turning in bed being sometimes sufficient to cause the bone to give way. Atrophy from the pressure of an aneurysm or of a simple tumour may erode the whole thickness of a bone, or may thin it out to such an extent that slight force is sufficient to break it. In general paralysis, and in the advanced stages of locomotor ataxia and other chronic diseases of the nervous system, an atrophy of all the bones sometimes takes place, and may proceed so far that multiple fractures are induced by comparatively slight causes. They occur most frequently in the ribs or long bones of the limbs, are not attended with pain, and usually unite satisfactorily, although with an excessive amount of callus. Attendants and nurses, especially in asylums, must be warned against using force in handling such patients, as otherwise they may be unfairly blamed for causing these fractures.

Among diseases which affect the skeleton as a whole and render the bones abnormally fragile, the most important are rickets, osteomalacia, and fibrous osteomyelitis. In these conditions multiple pathological fractures may occur, and they are prone to heal with considerable deformity. In osteomalacia, the bones are profoundly altered, but they are more liable to bend than to break; in rickets the liability is towards greenstick fractures.

Of the diseases affecting individual bones and predisposing them to fracture may be mentioned suppurative osteomyelitis, hydatid cysts, tuberculosis, syphilitic gummata, and various forms of new-growth, particularly sarcoma and secondary cancer. It is not unusual for the sudden breaking of the bone to be the first intimation of the presence of a new-growth. In adolescents, fibrous osteomyelitis affecting a single bone, and in adults, secondary cancer, are the commonest local causes of pathological fracture.

Intra-uterine fractures and fractures occurring during birth are usually associated with some form of violence, but in the majority of cases the foetus is the subject of constitutional disease which renders the bones unduly fragile.

TRAUMATIC FRACTURES

Traumatic fractures are usually the result of a severe force acting from without, although sometimes they are produced by muscular contraction.

When the bone gives way at the point of impact of the force, the violence is said to be direct, and a "fracture by compression" results, the line of fracture being as a rule transverse. The soft parts overlying the fracture are more or less damaged according to the weight and shape of the impinging body. Fracture of both bones of the leg from the passage of a wheel over the limb, fracture of the shaft of the ulna in warding off a stroke aimed at the head, and fracture of a rib from a kick, are illustrative examples of fractures by direct violence.

When the force is transmitted to the seat of fracture from a distance, the violence is said to be indirect, and the bone is broken by "torsion" or by "bending." In such cases the bone gives way at its weakest point, and the line of fracture tends to be oblique. Thus both bones of the leg are frequently broken by a person jumping from a height and landing on the feet, the tibia breaking in its lower third, and the fibula at a higher level. Fracture of the clavicle in its middle third, or of the radius at its lower end, from a fall on the outstretched hand, are common accidents produced by indirect violence. The ribs also may be broken by indirect violence, as when the chest is crushed antero-posteriorly and the bones give way near their angles. In fractures by indirect violence the soft parts do not suffer by the violence causing the fracture, but they may be injured by displacement of the fragments.

In fractures by muscular action the bone is broken by "traction" or "tearing." The sudden and violent contraction of a muscle may tear off an epiphysis, such as the head of the fibula, the anterior superior iliac spine, or the coronoid process of the ulna; or a bony process may be separated, as, for example, the tuberosity of the calcaneus, the coracoid process of the scapula, or the larger tubercle (great tuberosity) of the humerus. Long bones also may be broken by muscular action. The clavicle has snapped across during the act of swinging a stick, the humerus in throwing a stone, and the femur when a kick has missed its object. Fractures of ribs have occurred during fits of coughing and in the violent efforts of parturition.

Before concluding that a given fracture is the result of muscular action, it is necessary to exclude the presence of any of the diseased conditions that lead to pathological fracture.

Although the force acting upon the bone is the primary factor in the production of fractures, there are certain subsidiary factors to be considered. Thus the age of the patient is of importance. During infancy and early childhood, fractures are less common than at any other period of life, and are usually transverse, incomplete, and of the nature of bends. During adult life, especially between the ages of thirty and forty, the frequency of fractures reaches its maximum. In aged persons, although the bones become more brittle by the marrow spaces in their interior becoming larger and filled with fat, fractures are less frequent, doubtless because the old are less exposed to such violence as is likely to produce fracture.

Males, from the nature of their occupations and recreations, sustain fractures more frequently than do females; in old age, however, fractures are more common in women than in men, partly because their bones are more liable to be the seat of fatty atrophy from senility and disease, and partly because of their clothing--a long skirt--they are more exposed to unexpected or sudden falls.

#Clinical Varieties of Fractures.#--The most important subdivision of fractures is that into simple and compound.

In a simple or subcutaneous fracture there is no communication, directly or indirectly, between the broken ends of the bone and the surface of the skin. In a compound or open fracture, on the other hand, such a communication exists, and, by furnishing a means of entrance for bacteria, may add materially to the gravity of the injury.

A simple fracture may be complicated by the existence of a wound of the soft parts, which, however, does not communicate with the broken bone.

Fractures, whether simple or compound, fall into other clinical groups, according to (1) the degree of damage done to the bone, (2) the direction of the break, and (3) the relative position of the fragments.

(1) According to the Degree of Damage done to the Bone.--A fracture may be incomplete, for example in greenstick fractures, which occur only in young persons--usually below the age of twelve--while the bones are still soft and flexible. They result from forcible bending of the bone, the osseous tissue on the convexity of the curve giving way, while that on the concavity is compressed. The clavicle and the bones of the forearm are those most frequently the seat of greenstick fracture (Fig. 41). Fissures occur on the flat bones of the skull, the pelvic bones, and the scapula; or in association with other fractures in long bones, when they often run into joint surfaces. Depressions or indentations are most common in the bones of the skull.

The bone at the seat of fracture may be broken into several pieces, constituting a comminuted fracture. This usually results from severe degrees of direct violence, such as are sustained in railway or machinery accidents, and in gun-shot injuries (Fig. 2).

Sub-periosteal fractures are those in which, although the bone is completely broken across, the periosteum remains intact. These are common in children, and as the thick periosteum prevents displacement, the existence of a fracture may be overlooked, even in such a large bone as the femur.

A bone may be broken at several places, constituting a multiple fracture (Fig. 1).

Separation of bony processes, such as the coracoid process, the epicondyle of the humerus, or the tuberosity of the calcaneus, may result from muscular action or from direct violence. Separation of epiphyses will be considered later.

(2) According to the Direction of the Break.--Transverse fractures are those in which the bone gives way more or less exactly at right angles to its long axis. These usually result from direct violence or from end-to-end pressure. Longitudinal fractures extending the greater part of the length of a long bone are exceedingly rare. Oblique fractures are common, and result usually from indirect violence, bending, or torsion (Fig. 3). Spiral fractures result from forcible torsion of a long bone, and are met with most frequently in the tibia, femur, and humerus.

(3) According to the Relative Position of the Fragments.--The bone may be completely broken across, yet its ends remain in apposition, in which case there is said to be no displacement. There may be an angular displacement--for example, in greenstick fracture. In transverse fractures of the patella or of the olecranon there is often distraction or pulling apart of the fragments (Fig. 35). The broken ends, especially in oblique fractures, may override one another, and so give rise to shortening of the limb (Fig. 2). Where one fragment is acted upon by powerful muscles, a rotatory displacement may take place, as in fracture of the radius above the insertion of the pronator teres, or of the femur just below the small trochanter. The fragments may be depressed, as in the flat bones of the skull or the nasal bones. At the cancellated ends of the long bones, particularly the upper end of the femur and humerus, and the lower end of the radius, it is not uncommon for one fragment to be impacted or wedged into the substance of the other (Fig. 28).

Causes of Displacement.--The factors which influence displacement are chiefly mechanical in their action. Thus the direction and nature of the fracture play an important part. Transverse fractures with roughly serrated ends are less liable to displacement than those which are oblique with smooth surfaces. The direction of the causative force also is a dominant factor in determining the direction in which one or both of the fragments will be displaced. Gravity, acting chiefly upon the distal fragment, also plays a part in determining the displacement--for example, in fractures of the thigh or of the leg, where the lower segment of the limb rolls outwards, and in fractures of the shaft of the clavicle, where the weight of the arm carries the shoulder downwards, forwards, and medially. After the break has taken place and the force has ceased to act, displacement may be produced by rough handling on the part of those who render first aid, the careless or improper application of splints or bandages, or by the weight of the bedclothes.

In certain situations the contraction of unopposed, or of unequally opposed, groups of muscles plays a part in determining displacement. For example, in fracture immediately below the lesser trochanter of the femur, the ilio-psoas tends to tilt the upper fragment forward and laterally; in supra-condylar fracture of the femur, the muscles of the calf pull the lower fragment back towards the popliteal space; and in fracture of the humerus above the deltoid insertion, the muscles inserted into the inter-tubercular (bicipital) groove adduct the upper fragment.

REPAIR OF INJURIES OF BONE

In a simple fracture the vessels of the periosteum and the marrow being torn at the same time as the bone is broken, blood is poured out, and clots around and between the fragments. This clot is soon permeated by newly formed blood vessels, and by leucocytes and fibroblasts, the latter being derived from proliferation of the cells of the marrow and periosteum. The granulation tissue thus formed resembles in every particular that described in the repair of other tissues, except that the fibroblasts, being the offspring of cells which normally form bone, assume the functions of osteoblasts, and proceed to the formation of bone. The new bone may be formed either by a direct conversion of the fibrous tissue into osseous tissue, the osteoblasts arranging themselves concentrically in the recesses of the capillary loops, and secreting a homogeneous matrix in which lime salts are speedily deposited; or there may be an intermediate stage of cartilage formation, especially in young subjects, and in cases where the fragments are incompletely immobilised. The newly formed bone is at first arranged in little masses or in the form of rods which unite with each other to form a network of spongy bone, the meshes of which contain marrow.

The reparative material, consisting of granulation tissue in the process of conversion into bone, is called callus, on account of its hard and unyielding character. In a fracture of a long bone, that which surrounds the fragments is called the external or ensheathing callus, and may be likened to the mass of solder which surrounds the junction of pipes in plumber-work; that which occupies the position of the medullary canal is called the internal or medullary callus; and that which intervenes between the fragments and maintains the continuity of the cortical compact tissue of the shaft is called the intermediate callus. This intermediate callus is the only permanent portion of the reparative material, the external and internal callus being only temporary, and being largely re-absorbed through the agency of giant cells.

Detached fragments or splinters of bone are usually included in the callus and ultimately become incorporated in the new bone that bridges the gap.

In time all surplus bone is removed, the medullary canal is re-formed, the young spongy bone of the intermediate callus becomes more and more compact, and thus the original architectural arrangement of the bone may be faithfully reproduced. If, however, apposition is not perfect, some of the new bone is permanently required and some of the old bone is absorbed in order to meet the altered physiological strain upon the bone resulting from the alteration in its architectural form. In overriding displacement, even the dense cortical bone intervening between the medullary canal of the two fragments is ultimately absorbed and the continuity of the medullary canal is reproduced.

The amount of callus produced in the repair of a given fracture is greater when movement is permitted between the broken ends. It is also influenced by the character of the bone involved, being less in bones entirely ossified in membrane, such as the flat bones of the skull, than in those primarily ossified in cartilage.

If the fragments are widely separated from one another, or if some tissue, such as muscle, intervenes between them, callus may not be able to bring about a bony union between the fragments, and non-union results.

Bones divided in the course of an operation, for example in osteotomy for knock-knee, or wedge-shaped resection for bow-leg, are repaired by the same process as fractures.

#Excess of Callus.#--In comminuted fractures, and in fractures in which there is much displacement, the amount of callus is in excess, but this is necessary to ensure stability. In fractures in the vicinity of large joints, such as the hip or elbow, the formation of callus is sometimes excessive, and the projecting masses of new bone restrict the movements of the joint. When exuberant callus forms between the bones in fractures of the forearm, pronation and supination may be interfered with (Fig. 4). Certain nerve-trunks, such as the radial (musculo-spiral) in the middle of the arm, or the ulnar at the elbow-joint, may become included in or pressed upon by callus.

#Absorption of Callus.#--It sometimes happens that when an acute infective disease, especially one of the exanthemata, supervenes while a fracture is undergoing repair, the callus which has formed becomes softened and is absorbed. This may occur weeks or even months after the bone has united, with the result that the fragments again become movable, and it may be a considerable time before union finally takes place.

#Tumours of Callus.#--Tumours, such as chondroma and sarcoma, and cysts which are probably of the same nature as those met with in osteomyelitis fibrosa, are liable to occur in callus, or at the seat of old fractures, but the evidence so far is inconclusive as to the causative relationship of the injury to the new-growth. They are treated on the same lines as tumours occurring independently of fracture.

#Badly United Fracture--Mal-Union.#--Union with marked displacement of the fragments is most common in fractures that have not been properly treated--as, for example, those occurring in sailors at sea; and in cases in which the comminution was so great that accurate apposition was rendered impossible. It may also result from imperfect reduction, or because the apparatus employed permitted of secondary displacement. Restlessness on the part of the patient from intractability, delirium tremens, or mania, is the cause of mal-union in some cases; sometimes it has resulted because the patient was expected to die from some other lesion and the fracture was left untreated.

Whether or not any attempt should be made to improve matters depends largely on the degree of deformity and the amount of interference with function.

When interference is called for, if the callus is not yet firmly consolidated, it may be possible, under an anaesthetic, to bend the bone into position or to re-break it, either with the hands or by means of a strong mechanical contrivance known as an osteoclast. In the majority of cases, however, an open operation yields results which are more certain and satisfactory. When the deformity is comparatively slight, the bone is divided with an osteotome and straightened; when there is marked bending or angling, a wedge is taken from the convexity, as in the operation for bow-leg. To maintain the fragments in apposition it may be necessary to employ pegs, plates, bone-grafts, or other mechanical means. Splints and extension are then applied, and the condition is treated on the same lines as a compound fracture.

#Delayed Union.#--At the time when union should be firm and solid, it may be found that the fragments are only united by a soft cartilaginous callus, which for a prolonged period may undergo no further change, so that the limb remains incapable of bearing weight or otherwise performing its functions. The normal period required for union may be extended from various causes. The most important of these is general debility, but the presence of rickets or tuberculosis, or an intercurrent acute infectious disease, may delay the reparative process. The influence of syphilis, except in its gummatous form, in interfering with union is doubtful. The influence of old age as a factor in delaying union has been overestimated; in the great majority of cases, fractures in old people unite as rapidly and as firmly as those occurring at other periods of life.

Treatment.--The general condition of the patient should be improved, by dieting and tonics. One of the most reliable methods of hastening union in these cases is by inducing passive hyperaemia of the limb after the method advocated by Bier, and this plan should always be tried in the first instance. An elastic bandage is applied above the seat of fracture, sufficiently tightly to congest the limb beyond, and, to concentrate the congestion in the vicinity of the fracture, an ordinary bandage should be applied from the distal extremity to within a few inches of the break. The hyperaemia should be maintained for several hours (six to twelve) daily. An apparatus should be adjusted to enable the patient to get into the open air, and in fractures of the lower extremity the patient should move about with crutches in the intervals, putting weight on the fractured bone. This method of treatment should be persevered with for three or four weeks, and the limb should be massaged daily while the constricting bandage is off.

Among the other methods which have been recommended are the injection between the fragments of oil of turpentine (Mikulicz), a quantity of the patient's own blood (Schmieden), or alcohol and iodine; the forcible rubbing of the ends together, under an anaesthetic if necessary; and the administration of thyreoid extract. If these methods fail, the case should be treated as one of un-united fracture. As a rule, satisfactory union is ultimately obtained, although much patience is required.

#Non-Union.#--Sometimes the fragments become united by a dense band of fibrous tissue, and the reparative process goes no further--fibrous union. This is frequently the case in fractures of the patella, the olecranon, and the narrow part of the neck of the femur.

False Joint--Pseudarthrosis.--In rare cases the ends of the fragments become rounded and are covered with a layer of cartilage. Around their ends a capsule of fibrous tissues forms, on the inner aspect of which a layer of endothelium develops and secretes a synovia-like fluid. This is met with chiefly in the humerus and in the clavicle.

Failure of Union--"Un-united Fracture."--As the time taken for union varies widely in different bones, and ossification may ultimately ensue after being delayed for several months, a fracture cannot be said to have failed to unite until the average period has been long overpassed and still there is no evidence of fusion of the fragments. Under these conditions failure of union is a rare complication of fractures. In adults it is most frequently met with in the humerus, the radius and ulna (Fig. 6), and the femur; in children in the bones of the leg and in the forearm.

In a radiogram the bones in the vicinity of the fracture, particularly the distal fragment, cast a comparatively faint shadow, and there may even be a clear space between the fragments. When the parts are exposed by operation, the bone is found to be soft and spongy and the ends of the fragments are rarefied and atrophied; sometimes they are pointed, and occasionally absorption has taken place to such an extent that a gap exists between the fragments. The bone is easily penetrated by a bradawl, and if an attempt is made to apply plates, the screws fail to bite. These changes are most marked in the distal fragment.

The want of union is evidently due to defective activity of the bone-forming cells in the vicinity of the fracture. This may result from constitutional dyscrasia, or may be associated with a defective blood supply, as when the nutrient artery is injured. Interference with the trophic nerve supply may play a part, as cases are recorded by Bognaud in which union of fractures of the leg failed to take place after injuries of the spinal medulla causing paraplegia. The condition has been attributed to local causes, such as the interposition of muscle or other soft tissue between the fragments, or to the presence of a separated fragment of bone or of a sequestrum following suppuration. In our experience such factors are seldom present.

If the treatment recommended for delayed union fails, recourse must be had to operation, the most satisfactory procedure being to insert a bone graft in the form of an intra-medullary splint. In certain cases met with in the bones of the leg in children, the degree of atrophy of the bones is such that it has been found necessary to amputate after repeated attempts to obtain union by operative measures have failed.

In the tibia we have found that with the double electric saw a rod of bone can be rapidly and accurately cut, extending well above as well as below the site of fracture but unequally in the two directions; the rod is then reinserted into the trough from which it was taken with the ends reversed, so that a strong bridge of bone is provided at the seat of non-union.

CLINICAL FEATURES OF SIMPLE FRACTURES

In the first place, the history of the accident should be investigated, attention being paid to the nature of the violence--whether a blow, a twist, a wrench, or a crush, and whether the violence was directly or indirectly applied. The degree of the violence may often be judged approximately from the instrument inflicting it--whether, for example, a fist, a stick, a cart wheel, or a piece of heavy machinery. The position of the limb at the time of the injury; whether the muscles were braced to meet the blow or were lax and taken unawares; and the patient's sensations at the moment, such as his feeling something snap or tear, may all furnish information useful for purposes of diagnosis.

Signs of Fracture.--The most characteristic signs of fracture are unnatural mobility, deformity, and crepitus.

Unnatural mobility--that is, movement between two segments of a limb at a place where movement does not normally occur--may be evident when the patient makes attempts to use his limb, or may only be elicited when the fragments are seized and moved in opposite directions. Deformity, or the part being "out of drawing" in comparison with the normal side, varies with the site and direction of the break, and depends upon the degree of displacement of the fragments. Crepitus is the name applied to the peculiar grating or clicking which may be heard or felt when the fractured surfaces are brought into contact with one another.

The presence of these three signs in association is sufficient to prove the existence of a fracture, but the absence of one or more of them does not negative this diagnosis. There are certain fallacies to be guarded against. For example, a fracture may exist and yet unnatural mobility may not be present, because the bones are impacted into one another, or because the fracture is an incomplete one. Again, the extreme tension of the swollen tissues overlying the fracture may prevent the recognition of movement between the fragments. Deformity also may be absent--as, for instance, when there is no displacement of the fragments, or when only one of two parallel bones is broken, as in the leg or forearm. Similarly, crepitus may be absent when impaction exists, when the fragments completely override one another, or are separated by an interval, or when soft tissues, such as torn periosteum or muscle, are interposed between them. A sensation simulating crepitus may be felt on palpating a part into which blood has been extravasated, or which is the seat of subcutaneous emphysema. The creaking which accompanies movements in certain forms of teno-synovitis and chronic joint disease, and the rubbing of the dislocated end of a bone against the tissues amongst which it lies, may also be mistaken for the crepitus of fracture.

It is not advisable to be too diligent in eliciting these signs, because of the pain caused by the manipulations, and also because vigorous handling may do harm by undoing impaction, causing damage to soft parts or producing displacement which does not already exist, or by converting a simple into a compound fracture.

It is often necessary for purposes of diagnosis to administer a general anaesthetic, particularly in injuries of deeply placed bones and in the vicinity of joints. Before doing so, the appliances necessary for the treatment of the injury should be made ready, in order that the fracture may be reduced and set before the patient regains consciousness.

Radiography in the Diagnosis of Fractures.--While radiography is of inestimable value in the diagnosis of many fractures and other injuries, particularly in the vicinity of joints, the student is warned against relying too implicitly on the evidence it seems to afford.

A radiogram is not a photograph of the object exposed to the X-rays but merely a picture of its shadow, or rather of a series of shadows of the different structures, which vary in opacity. As the rays emanate from a single point in the vacuum tube, and as they are not, like the sun's rays, approximately parallel, the shadows they cast are necessarily distorted. Hence, in interpreting a radiogram, it is necessary to know the relative positions of the point from which the rays proceed, the object exposed, and the plate on which the shadow is registered. The least distortion takes place when the object is in contact with the plate, and the shadow of that part of the object which lies perpendicularly under the light is less distorted than that of the parts lying outside the perpendicular. The light and the plate remaining constant, the amount of distortion varies directly with the distance between the object and the plate.

To ensure accuracy in the diagnosis of fracture by the X-rays, it is necessary to take two views of the limb--one in the sagittal and the other in the coronal plane. By the use of the fluorescent screen, the best positions from which to obtain a clear impression of the fracture may be determined before the radiograms are taken. Stereoscopic radiograms may be of special value in demonstrating the details of a fracture that is otherwise doubtful.

Imperfect technique and faulty interpretation of the pictures obtained lead to certain fallacies. In young subjects, for example, epiphysial lines may be mistaken for fractures, or the ossifying centres of epiphyses for separated fragments of bone. The os trigonum tarsi has been mistaken for a fracture of the talus. In the vicinity of joints the bones may be crossed by pale bands, due to the rays traversing the cavity of the joint. In this way fracture of the olecranon or of the clavicle may be simulated. The neck of the femur may appear to be fractured if a foreshortened view is taken.

It is possible, on the other hand, to overlook a fracture--for example, if there is no displacement, or if the line of fracture is crossed by the shadow of an adjacent bone. In deeply placed bones such as those about the hip, or in bones related to dense, solid viscera--for example, ribs, sternum, or dorsal vertebrae--it is sometimes difficult to obtain conclusive evidence of fracture in a radiogram.

It is to be borne in mind also, and especially from the medico-legal point of view, that, as early callus does not cast a deep shadow in a radiogram, the appearance of fracture may persist after union has taken place. The earliest shadow of callus appears in from fourteen to twenty-one days, and can hardly be relied upon till the fourth or sixth week. The disturbed perspective produced by divergence of the rays may cause the fragments of a fracture to appear displaced, although in reality they are in good position. If the limb and the plate are not parallel, the bones may appear to be distorted, and errors in diagnosis may in this way arise. In this relation it should be mentioned that perfect apposition of the fragments and anatomically accurate restoration of the outline of the bones are not always essential to a good functional result.

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As most of the remaining signs are common to all the lesions from which fractures have to be distinguished, their diagnostic value must be carefully weighed.

Interference with Function.--As a rule, a broken bone is incapable of performing its normal function as a lever or weight-bearer; but when a fracture is incomplete, when the fragments are impacted, or when only one of two parallel bones is broken, this does not necessarily follow. It is no uncommon experience to find a patient walk into hospital with an impacted fracture of the neck of the femur or a fracture of the fibula; or to be able to pronate and supinate the forearm with a greenstick fracture of the radius or a fracture of the ulna.

Pain.--Three forms of pain may be present in fractures: pain independent of movement or pressure; pain induced by movement of the limb; and pain elicited on pressure or "tenderness." In injuries by direct violence, pain independent of movement and pressure is never diagnostic of fracture, as it may be due to bruising of soft tissues. In injuries resulting from indirect violence, however, pain localised to a spot at some distance from the point of impact is strongly suggestive of fracture--as, for example, when a patient complains of pain over the clavicle after a fall on the hand, or over the upper end of the fibula after a twist of the ankle. Pain elicited by attempts to move the damaged part, or by applying pressure over the seat of injury, is more significant of fracture. Pain elicited at a particular point on pressing the bone at a distance, "pain on distal pressure,"--for example, pain at the lower end of the fibula on pressing near its neck, or at the angle of a rib on pressing near the sternum,--is a valuable diagnostic sign of fracture. When nerve-trunks are implicated in the vicinity of a fracture, pain is often referred along the course of their distribution.

Localised swelling comes on rapidly, and is due to displacement of the fragments and to haemorrhage from the torn vessels of the marrow and periosteum.

Discoloration accompanies the swelling, and is often widespread, especially in fracture of bones near the surface and when the tension is great. It is not uncommon to find over the ecchymosed area, especially over the shin-bone, large blebs containing blood-stained serum. In fractures of deep-seated bones, discoloration may only show on the surface after some days, and at a distance from the break.

Alterations in the relative position of bony landmarks are valuable diagnostic guides. Alteration in the length of the limb, usually in the direction of shortening, is also an important sign. Before drawing deductions, care must be taken to place both limbs in the same position and to determine accurately the fixed points for measurement, and also to ascertain if the limbs were previously normal.

Shock is seldom a prominent symptom in uncomplicated fractures, although in old and enfeebled patients it may be serious and even fatal. During the first two or three days after a fracture there is almost invariably some degree of traumatic fever, indicated by a rise of temperature to 99 deg. or 100 deg. F.

#Complications.#--Injuries to large arteries are not common in simple fractures. The popliteal artery, however, is liable to be compressed or torn across in fractures of the lower end of the femur; extravasation of blood from the ruptured artery and gangrene of the limb may result. If large veins are injured, thrombosis may occur, and be followed by pulmonary embolism.

Injuries to nerve-trunks are comparatively common, especially in fractures of the arm, where the radial (musculo-spiral) nerve is liable to suffer.

The nerve may be implicated at the time of the injury, being compressed, bruised, lacerated, or completely torn across by broken fragments, or it may be involved later by the pressure of callus. The symptoms depend upon the degree of damage sustained by the nerve, and vary from partial and temporary interference with sensation and motion to complete and permanent abrogation of function.

In rare instances fat embolism is said to occur, and fat globules are alleged to have been found in the urine. In persons addicted to excess of alcohol, delirium tremens is a not infrequent accompaniment of a fracture which confines the patient to bed.

#Prognosis in Simple Fractures.#--Danger to life in simple fractures depends chiefly on the occurrence of complications. In old people, a fracture of the neck of the femur usually necessitates long and continuous lying on the back, and bronchitis, hypostatic pneumonia, and bed-sores are prone to occur and endanger life. Fractures complicated with injury to internal organs, and fractures in which gangrene of the limb threatens, are, of course, of grave import.

The prognosis as regards the function of the limb should always be guarded, even in simple fractures. Incidental complications are liable to arise, delaying recovery and preventing a satisfactory result, and these not only lead to disappointment, but may even form a ground for actions for malpraxis.

The chief and most frequent cause of permanent disability after fracture is angular displacement. A comparatively small degree of angularity may lead to serious loss of function, especially in the lower limb; the joints above and below the fracture are placed at a disadvantage, arthritic changes result from the abnormal strain to which they are subjected, and rarefaction of the bone may also ensue.

Fibrous union is a common result in fractures of the neck of the femur in old people and in certain other fractures, such as fracture of the patella, of the olecranon, coronoid and coracoid processes, and although this does not necessarily involve interference with function, the patient should always be warned of the possibility.

Impairment of growth and eventual shortening of the limb may result from involvement of an epiphysial junction.

Stiffness of joints is liable to follow fractures implicating articular surfaces, or it may result from arthritic changes following upon the injury.

Osseous ankylosis is not a common sequel of simple fractures, but locking of joints from the mechanical impediment produced by the union of imperfectly reduced fragments, or from masses of callus, is not uncommon, especially in the region of the elbow.

Wasting of the muscles and oedema of the limb often delay the complete restoration of function. Delayed union, want of union, and the formation of a false joint have already been referred to.

#Treatment.#--The treatment of a fracture should be commenced as soon after the accident as possible, before the muscles become contracted and hold the fragments in abnormal positions, and before the blood and serum effused into the tissues undergo organisation.

Care must be taken during the transport of the patient that no further damage is done to the injured limb. To this end the part must be secured in some form of extemporised splint, the apparatus being so designed as to control not only the broken fragments, but also the joints above and below the fracture.

When the ordinary method of removing the clothes involves any risk of unduly moving the injured part, they should be slit open along the seams.

The patient should be placed on a firm straw, horse-hair, or spring mattress, stiffened in the case of fractures of the pelvis or lower limbs by fracture-boards inserted beneath the mattress. Special mattresses constructed in four pieces, to facilitate the nursing of the patient, are sometimes used.

In many cases, particularly in muscular subjects, in restless alcoholic patients, and in those who do not bear pain well, a general anaesthetic is a valuable aid to the accurate setting of a fracture, as well as a means of rendering the diagnosis more certain.

The procedure popularly known as "setting a fracture" consists in restoring the displaced parts to their normal position as nearly as possible, and is spoken of technically as the reduction of the fracture.

The Reduction of Fractures.--In some cases the displacement may be overcome by relaxing the muscles acting upon the fragments, and this may be accomplished by the stroking movements of massage. In most cases, however, it is necessary, after relaxing the muscles, to employ extension, by making forcible but steady traction on the distal fragment, while counter-extension is exerted on the proximal one, either by an assistant pulling upon that portion of the limb, or by the weight of the patient's body. The fragments having been freed, and any shortening of the limb corrected in this way, the broken ends are moulded into position--a process termed coaptation.

The reduction of a recent greenstick fracture consists in forcibly straightening the bend in the bone, and in some cases it is necessary to render the fracture complete before this can be accomplished.

In selecting a means of retaining the fragments in position after reduction, the various factors which tend to bring about re-displacement must be taken into consideration, and appropriate measures adopted to counteract each of these.

In addition to retaining the broken ends of the bone in apposition, the after-treatment of a fracture involves the taking of steps to promote the absorption of effused blood and serum, to maintain the circulation through the injured parts, and to favour the repair of damaged muscles and other soft tissues. Means must also be taken to maintain the functional activity of the muscles of the damaged area, to prevent the formation of adhesions in joints and tendon sheaths, and generally to restore the function of the injured part.

Practical Means of Effecting Retention--By Position.--It is often found that only in one particular position can the fragments be made to meet and remain in apposition--for example, the completely supine position of the forearm in fracture of the radius just above the insertion of the pronator teres. Again, in certain cases it is only by relaxing particular groups of muscles that the displacement can be undone--as, for instance, in fracture of the bones of the leg, or of the femur immediately above the condyles, where flexion of the knee, by relaxing the calf muscles, permits of reduction.

Massage and Movement in the Treatment of Fractures.--Lucas-Championniere, in 1886, first pointed out that a certain amount of movement between the ends of a fractured bone favours their union by promoting the formation of callus, and advocated the treatment of fractures by massage and movement, discarding almost entirely the use of splints and other retentive appliances. We were early convinced by the teaching of Lucas-Championniere, and have adopted his principles in fractures.

In the majority of cases the massage and movement are commenced at once, but circumstances may necessitate their being deferred for a few days. The measures adopted vary according to the seat and nature of the fracture, but in general terms it may be stated that after the fracture has been reduced, the ends of the broken bone are retained in position, and gentle massage is applied by the surgeon or by a trained masseur. The lubricant may either be a powder composed of equal parts of talc and boracic acid, or an oily substance such as olive oil or lanolin. The rubbing should never cause pain, but, on the contrary, should relieve any pain that exists, as well as the muscular spasm which is one of the most important causes of pain and of displacement in recent fractures. The parts on the proximal side of the injured area are first gently stroked upwards to empty the veins and lymphatics, and to disperse the effused blood and serum. The process is then applied to the swollen area, and gradually extended down over the seat of the fracture and into the parts beyond. In this way the circulation through the damaged segment of the limb is improved, the veins are emptied of blood, the removal of effused fluid is stimulated, and the muscular irritability allayed. The joints of the limb are gently moved, care being taken that the broken ends of the bone are not displaced. After the rubbing has been continued for from fifteen to twenty minutes, the limb is placed in a comfortable position, and retained there by pillows, sand-bags, or, if found more convenient, by a light form of splint.

The massage is repeated once each day; the sittings last from ten to fifteen minutes. The sequence should be, first, massage; second, passive movement; and third, active movement. At first massage predominates, and more passive than active movement; gradually massage is lessened and movements are increased, active movements ultimately preponderating.

Splints and other Appliances.--The appropriate splints for individual fractures and the method of applying them will be described later; but it may here be said that the general principle is that when dealing with a part where there is a single bone, as the thigh or upper arm, the splint should be applied in the form of a ferrule to surround the break; while in situations where there are two parallel bones, as in the forearm and leg, the splint should take the form of a box.

Simple wooden splints of plain deal board or yellow pine, sawn to the appropriate length and width; or Gooch's splinting, which consists of long strips of soft wood, glued to a backing of wash-leather, are the most useful materials. Gooch's splinting has the advantage that when applied with the leather side next the limb it encircles the part as a ferrule; while it remains rigid when the wooden side is turned towards the skin. Perforated sheet lead or tin, stiff wire netting, and hoop iron also form useful splints.

When it is desirable that the splint should take the shape of the part accurately, a plastic material may be employed. Perhaps the most convenient is poroplastic felt, which consists of strong felt saturated with resin. When heated before a fire or placed in boiling water, it becomes quite plastic and may be accurately moulded to any part, and on cooling it again becomes rigid. The splint should be cut from a carefully fitted paper pattern. Millboard, leather, or gutta-percha softened in hot water, and moulded to the part, may also be employed.

In conditions where treatment by massage and movement is impracticable, and where movable splints are inconvenient, splints of plaster of Paris, starch, or water-glass are sometimes used, especially in the treatment of fractures of the leg. When employed in the form of an immovable case, they are open to certain objections--for example, if applied immediately after the accident they are apt to become too tight if swelling occurs; and if applied while swelling is still present, they become slack when this subsides, so that displacement is liable to occur.

When it is desired to enclose the limb in a plaster case, coarse muslin bandages, 3 yards long, and charged with the finest quality of thoroughly dried plaster of Paris, are employed. The "acetic plaster bandages" sold in the shops set most quickly and firmly. Boracic lint or a loose stocking is applied next the skin, and the bony prominences are specially padded. The plaster bandage is then placed in cold water till air-bubbles cease to escape, by which time it is thoroughly saturated, and, after the excess of water is squeezed out, is applied in the usual way from below upward. From two to four plies of the bandage are required. In the course of half an hour the plaster should be thoroughly set. To facilitate the removal of a plaster case the limb should be immersed for a short time in tepid water.

A convenient and efficient splint is made by moulding two pieces of poroplastic felt to the sides of the limb, and fixing them in position with an elastic webbing bandage; this apparatus can be easily removed for the daily massage.

Padding is an essential adjunct to all forms of splints. The whole part enclosed in the splint must be covered with a thick layer of soft and elastic material, such as wool from which the fat has not been removed. All hollows should be filled up, and all bony projections specially protected by rings of wadding so arranged as to take the pressure off the prominent point and distribute it on the surrounding parts. Opposing skin surfaces must always be separated by a layer of wool or boracic lint. A bandage should never be applied to the limb underneath the splints and pads, as congestion or even gangrene may be induced thereby.

#Operative Treatment of Simple Fractures.#--Operation in simple fracture is specially called for (1) in fracture into or near a joint where a permanently displaced fragment will cause locking of the joint; (2) when fragments are drawn apart, as in fractures of the patella or olecranon; (3) when displacement, especially shortening, cannot be remedied by other means; (4) when complications are present, such as a torn nerve-trunk or a main artery; (5) when non-union is to be feared, as in certain cases of fracture of the neck of the femur in old people. Under such circumstances it is necessary to expose the fracture by operation, and to place the fragments in accurate apposition, if necessary, fixing them in position by wires, pegs, plates, or screws (Op. Surg., p. 52). Operative interference is usually delayed till about five to seven days after the injury, by which time the effect of other measures will have been estimated, accurate information obtained by means of the X-rays regarding the nature of the lesion and the position of the fragments, and the tissues recovered their normal powers of resistance. Such operations, however, are not to be undertaken lightly, as they are often difficult, and if infection takes place the results may be disastrous. Arbuthnot Lane and Lambotte advocate a more general resort to operative measures, even in simple and uncomplicated fractures, and it must be conceded that in many fractures an open operation affords the only means of securing accurate apposition and alignment of the fragments.

Both before and after operation, massage and movement are to be carried out, as in fractures treated by other methods.

COMPOUND FRACTURES

The essential feature of a compound fracture is the existence of an open wound leading down to the break in the bone. The wound may vary in size from a mere puncture to an extensive tearing and bruising of all the soft parts.

A fracture may be rendered compound from without, the soft parts being damaged by the object which breaks the bone--as, for example, a cart wheel, a piece of machinery, or a bullet. Sloughing of soft parts resulting from the pressure of improperly applied splints, also, may convert a simple into a compound fracture. On the other hand, a simple fracture may be rendered compound from within--for example, a sharp fragment of bone may penetrate the skin; this is the least serious variety of compound fracture.

As a rule, it is easy to recognise that the fracture is compound, as the bone can either be seen or felt.

The prognosis depends on the success which attends the efforts to make and to keep the wound aseptic, as well as on the extent of damage to the tissues. When asepsis is secured, repair takes place as in simple fracture, only it usually takes a little longer; sometimes the reason for the delay is obvious, as when the compound fracture is the result of a more severe form of violence and where there is comminution and loss of one or more portions of bone that would have contributed to the repair. Sometimes the delay cannot be so explained; Bier suggested that it is due to the escape of blood at the wound, whereas in simple fractures the blood is retained and assists in repair.

If sepsis gains the upper hand in a compound fracture there is, firstly, the risk of infection of the marrow--osteomyelitis--which in former times was liable to result in pyaemia; in the second place, not only do loose fragments tend to die and be thrown off as sequestra, but the ends of the fragments themselves may undergo necrosis; involving as this does the dense cortical bone of the shaft, the dead bone is slow in being separated, and until it is separated and thrown off, no actual repair can take place. The sepsis stimulates the bone-forming tissues and new bone is formed in considerable amount, especially on the surface of the shaft in the vicinity of the fracture; in macerated specimens it presents a porous, crumbling texture. Sometimes the new bone--which corresponds to the involucrum of an osteomyelitis--imprisons a sequestrum and prevents its extrusion, in which case one or more sinuses may persist indefinitely. Cases are met with where such sinuses have existed for the best part of a long life and have ultimately become the seat of epithelioma.

It should be noted that all the above changes can be followed in skiagrams.

Treatment.--The leading indication is to ensure asepsis. Even in the case of a small punctured wound caused by a pointed fragment coming through the skin it is never wise to assume that the wound is not infected. It is much safer to enlarge such a wound, pare away the bruised edges, and disinfect the raw surfaces.

In cases of extensive laceration of the soft parts, all soiled, bruised, or torn portions of tissue should be clipped away with scissors, blood-clots removed, and the bleeding arrested by forci-pressure or ligature. If there is any reason to believe that the wound is infected, any fragments of bone completely separated from the periosteum should be removed. In comminuted fractures, extension applied by strips of plaster or by means of ice-tong callipers or Steinmann's apparatus (p. 150) often facilitates replacement of the fragments and their retention in position. Plates and screws are not recommended for comminuted fractures, owing to the mechanical difficulty of fixing a number of small fragments and the risks of infection. The wound should be purified with eusol, and the surrounding parts painted with iodine. On the whole, it is safer not to attempt to obtain primary union by completely closing such wounds, but rather to drain or pack them. To increase the local leucocytosis and so check the spread of infection, a Bier's constricting bandage may be applied.

In other respects the treatment is carried out on the same lines as in simple fractures, provision being made for dressing the wound without disturbance of the fracture. Massage and movement should be commenced after the wound is healed and the condition has become analogous to a simple fracture.

#Question of Amputation in Compound Fractures.#--Before deciding to perform primary amputation of a limb for compound fracture, the surgeon must satisfy himself (1) that the attainment of asepsis is impossible; (2) that the soft parts are so widely and so grossly damaged that their recovery is improbable; (3) that the vascular and nervous supply of the parts beyond has been rendered insufficient by destruction of the main blood vessels and nerve-trunks; (4) that the bones have been so shattered as to be beyond repair; and (5) that the limb, even if healing takes place, will be less useful than an artificial one.

In attempting to save the limb of a young subject, it is justifiable to run risks which would not be permissible in the case of an older person. To save an upper limb, also, risks may be run which would not be justifiable in the case of a lower limb, because, while a serviceable artificial leg can readily be procured, any portion of the natural hand or arm is infinitely more useful than the best substitute which the instrument-maker can contrive. The risk involved in attempting to save a limb should always be explained to the patient or his guardian, in order that he may share the responsibility in case of failure.

Whether or not the amputation should be performed at once, depends upon the general condition of the patient. If the injury is a severe one, and attended with a profound degree of shock, it is better to wait for twenty-four or forty-eight hours. Meanwhile the wound is purified, and the limb wrapped in a sterile dressing. Means are taken to counteract shock and to maintain the patient's strength, and evidence of infection or of haemorrhage is carefully watched for. When the shock has passed off, the operation is then performed under more favourable auspices. Clinical experience has proved that by this means the mortality of primary amputations may be materially diminished, especially in injuries necessitating removal of an entire limb.

Having decided to amputate, it is important to avoid having bruised, torn, or separated tissues in the flaps, as these are liable to slough or to become the seat of infection. In this connection it should be borne in mind that the damage to soft tissues is always wider in extent than appears from external examination.

The attempt to save a limb may fail and amputation may be called for later because of spreading infective processes, osteomyelitis, or gangrene; to prevent exhaustion from prolonged suppuration and toxin absorption; or on account of secondary haemorrhage.

#Gun-shot Injuries of Bone.#--Fractures resulting from the impact of bullet or fragments of shell are of necessity compound, and are usually infected from the outset by organisms carried in by the missile or by portions of clothing or other foreign material. Not infrequently the missile lodges in the bone.

The extent of the injury to the bone varies infinitely, from a mere chip or gutter-shaped wound to complete pulverisation of the portion struck. The fracture is of the comminuted and fissured variety, the cracks radiating from the point of impact and extending for a considerable distance, sometimes even implicating the articular surface of the bone some inches away. In comminuted fractures of the shafts of long bones there is often a large wedge-shaped fragment completely isolated from the rest, and in the presence of infection this may form a sequestrum. Healing is often delayed by the separation of sequestra, which takes place slowly, and union is attended with excessive formation of callus. When a considerable section of the shaft has been lost, want of union, fibrous union, or the formation of a false joint may result.

The treatment is carried out on the same lines as in other forms of compound fracture, except that mention should be made of the irrigation method of Carrel, found to be the most potent means of overcoming the associated infection.

SEPARATION OF EPIPHYSES[1]

[1] We do not employ the term "diastasis," which has been used in different senses by different writers.

In young subjects before the bones are fully developed the epiphyses may be separated from the diaphyses. The use of the X-rays has added greatly to our knowledge of these lesions.

It is useful to remember that in the upper extremity the epiphyses in the regions of the shoulder and wrist, and, in the lower extremity, those in the region of the knee, are the latest to unite; and that it is in these situations that growth in length of the bone goes on longest and most actively (twenty to twenty-one years). Injuries of these epiphyses, therefore, are most liable to interfere with the growth of the limb.

An epiphysis is nourished from the articular arteries and through the vessels of the periosteum.

Pathological Separation of Epiphyses.--There are certain pathological conditions, such as rickets, scurvy, congenital syphilis, tubercle, suppurative conditions, and tumour growths, which render separation of the epiphyses liable to occur from injuries altogether insufficient to produce such lesions under normal conditions.

#Traumatic Separations.#[2]--Speaking generally, it may be said that injuries which in an adult would be liable to produce dislocation, are in a young person more apt to cause separation of an epiphysis. Indirect violence, especially when exerted in such a way as to combine traction with torsion,--for example, when the foot is caught in the spokes of a carriage wheel,--is the commonest cause of epiphysial separation. Direct violence is a much less frequent cause. Muscular action occasionally produces separation of the epiphyses--for example, the anterior superior iliac spine, the small trochanter of the femur, or the upper end of the fibula.

[2] We desire here to acknowledge our indebtedness to Mr. John Poland's work on Traumatic Separation of the Epiphyses.

The majority of separations take place between the eleventh and the eighteenth years, chiefly because during this period the injuries liable to produce such lesions are most common. They do not occur after twenty-five, because by that time all the epiphyses have united. In females this form of injury is rare, and almost invariably occurs before puberty.

The following are the most common seats of separation in the order of their frequency: (1) the lower end of the femur; (2) the lower end of the radius; (3) the upper end of the humerus; (4) the lower end of the humerus; (5) the lower end of the tibia; and (6) the upper end of the tibia.

Morbid Anatomy.--In a true separation the epiphysial cartilage remains attached to the epiphysis. As a rule the epiphysis is not completely separated from the diaphysis, the common lesion being a separation along part of the epiphysial line, with a fracture running into the diaphysis (Fig. 8). It is not uncommon for more than one epiphysis to be separated by the same accident--for example, the lower end of the femur and the upper ends of the tibia and fibula. Epiphysial separations, like fractures, may be simple or compound. Incomplete separations are liable to be overlooked at the time of the accident, but there is reason to believe that they may form the starting-point of disease. Strain of the epiphysial junction--the juxta-epiphysial strain of Ollier--is a common injury in young children.

Clinical Features.--The symptoms simulate those of dislocation rather than of fracture. Thus, unnatural mobility at an epiphysial junction may closely resemble movement at the adjacent joint, especially when the epiphysis is an intra-capsular one. The relationship of the bony points, however, serves to indicate the nature of the lesion. The degree of deformity is often slight, because the transverse direction of the lesion, the breadth of the separated surfaces, and the firmness of the periosteal attachment along the epiphysial line often prevent displacement. In many cases a distinct, rounded, smooth, and regular ridge, caused by the projection of the diaphysis, can be felt. The peculiar "muffled" nature of the crepitus is one of the most characteristic signs. The older the patient, and the further ossification has progressed, the more does the crepitus resemble that of fracture.

Of the subsidiary signs, loss of power in the limb is one of the most constant; indeed, in young children it is sometimes the first, and may be the only, sign that attracts attention. Pain and tenderness along the epiphysial line are valuable signs, particularly when the lesion is due to indirect or muscular violence and there is no bruising of soft parts. Localised swelling, accompanied by ecchymosis, is often marked; and the adjacent joint may be distended with fluid.

As distinguishing this injury from a dislocation, it may be noted that in epiphysial separation there is no snap felt when the deformity is reduced, the tendency to re-displacement is greater, and the amount of relief given by reduction less than in dislocation. The use of the Roentgen rays at once establishes the diagnosis.

Prognosis and Results.--In the majority of cases union takes place satisfactorily by the formation of callus in the spongy tissue of the diaphysis and on the deep surface of the periosteum. In spite of the favourable nature of the prognosis in general, however, the friends of the patient should be warned that a completely satisfactory result cannot always be relied upon.

Deformity, with stiffness and locking at the adjacent joint, especially at the elbow, may result from imperfect reduction, or from exuberant callus. Arrest of growth of the bone in length is a rare sequel, and when it occurs, it is due, not to premature union of the epiphysis with the shaft, but to diminished action at the ossifying junction.

When the growth of one of the bones of the leg or forearm is arrested after separation of its epiphysis while the other bone continues to grow, the foot or hand is deviated towards the side of the shorter one.

Partial separations may be overlooked at the time of the accident and cause trouble later from bending of the bone, as in one variety of coxa vara. The epiphysis at the lower end of the femur may be displaced into the ham and press on the popliteal vessels.

Treatment.--The general principles which govern the treatment of fractures apply equally to epiphysial separations, the essential being the accurate replacement of the epiphysis.

In compound separations of epiphysis, the end of the diaphysis may be pushed through the skin. The entrance of sepsis may prove an obstacle to any operative measure that would otherwise be indicated.

II. INJURIES OF JOINTS

SURGICAL ANATOMY--INJURIES: Contusions; Wounds; Sprains; Dislocations--TRAUMATIC DISLOCATIONS: Causes: Varieties; Clinical features; Treatment--Compound dislocations--Old-standing dislocations.

#Surgical Anatomy.#--The function of a joint is to permit of the movement of one bone upon another. The articular surfaces are covered with a thin layer of hyaline cartilage, and are retained in apposition by the tension of ligaments and of the muscles surrounding the joint. The articular capsule (capsular ligament) is directly continuous with the periosteum, and is lined by a synovial layer, which at the line of attachment of the capsule is reflected on to the bone as far as the articular cartilage. The synovial layer invests intra-articular ligaments, and is projected into the interior of the joint in the form of loose folds wherever the articulating surfaces are not in immediate contact. The surface of the synovial layer is covered with minute processes or villi, which in diseased conditions may become hypertrophied. The synovia owes its lubricating property to mucin, derived from the solution of the endothelial cells on the free surface of the synovial layer. The opposing surfaces of a joint being always in accurate contact, the so-called cavity is only a potential one. If fluid is poured out into the joint, the synovial layer and the capsule are put upon the stretch, causing discomfort or actual pain, which is partly relieved by slightly flexing the joint. If the distension persists, the ligaments become elongated and the joint unstable.

The common origin of bone, cartilage, periosteum, and synovial layer from one parent tissue of the embryo, accords with the readiness with which any one of these tissues may be converted into another under traumatic or pathological influences; and how in ligaments and in synovial membrane foci of hyaline cartilage may form and, after increasing in size, undergo ossification.

Joints derive an abundant blood supply through the articular arteries. The lymphatics, which take origin in the synovial layer, pass to efferent vessels which run in the intermuscular and other connective-tissue planes of the limb. The nerve supply is derived chiefly from the nerves distributed to the muscles acting on the joint and to the skin over it.

#Sources of Joint Strength.#--The capacity of a joint to resist dislocation depends upon (1) the shape of its osseous elements; (2) the strength and arrangement of its ligaments; (3) the support it receives from muscles or tendons placed in relation to it; and (4) the relative stability of adjacent structures. While all these factors contribute to the strength of a given joint, one or other of them usually predominates, so that certain joints are osseously strong, others are ligamentously strong, while a few depend chiefly upon adjacent muscles for their stability.

The hip and elbows are the best examples of joints deriving their strength mainly from the architectural arrangement of the constituent bones. These joints are dislocated only by extreme degrees of violence, and not infrequently--especially in the elbow--portions of the bones are fractured before the articular surfaces are separated.

The knee, the wrist, the carpal, the tarsal, and the clavicular joints depend for their stability almost entirely on the strength of their ligaments. These joints are rarely dislocated, but as the main incidence of the violence falls on the ligaments they are frequently sprained.

The shoulder is the typical example of a joint depending for its security chiefly upon the muscles and tendons passing over it, and hence the frequency with which it is dislocated when the muscles are taken unawares. At the same time the great mobility of the scapula and clavicle materially increases the stability of the shoulder-joint. The tendons passing in relation to the knee, ankle, and wrist add to the stability of these joints.

The proximity of an easily fractured bone also contributes to prevent dislocation of certain joints--for example, fracture of the clavicle prevents an impinging force expending itself on the shoulder-joint; and the frequency of Colles' fracture of the radius, and of Pott's fracture of the fibula, doubtless accounts to some extent for the rarity of dislocation of the wrist and ankle-joints respectively. The immunity from dislocation which the joints of young subjects enjoy is partly due to the ease with which an adjacent epiphysis is separated.

The mechanical axiom that "what is gained in movement is lost in stability" applies to joints, those which have the widest range of movement being the most frequently dislocated.

* * * * *

The injuries to which a joint is liable are Contusions, Wounds, Sprains, and Dislocations.

#Contusions of Joints.#--Contusion is the mildest form of injury to a joint. Whether the violence is transmitted from a distance, as in contusion of the hip from a fall on the feet, or acts more directly, as in a fall on the great trochanter, the bones are violently driven against one another, and the force expends itself on their articular surfaces. The articular cartilages and the underlying spongy bone, as well as the synovial lining, are bruised, and there is an effusion of blood and serous fluid into the joint and surrounding tissues.

The most prominent clinical features are swelling and discoloration. The swelling, especially in superficially placed joints, is an early and marked symptom, and is mainly due to the effusion of blood into the joint (haemarthrosis). In deeply placed joints, discoloration may not appear on the surface for some days, especially if the violence has been indirect. The joint is kept in the flexed position, and is painful only when moved. In haemophilic subjects, considerable effusion of blood into a joint may follow the most trivial injury.

A slight degree of serous effusion into the joint (hydrarthrosis) often persists for some time, and tuberculous affections of joints not infrequently date from a contusion.

The treatment is the same as for sprains (p. 36).

#Wounds of Joints.#--The importance of accidental wounds of joints--such, for example, as result from a stab with a penknife or the spike of a railing--lies in the fact that they are liable to be followed by infection of the synovial cavity. The infection may involve only the synovial layer (septic synovitis), or may spread to all the elements of the joint (septic arthritis). These conditions are described with diseases of joints.

Penetration of the joint may sometimes be recognised by the escape of synovia from the wound, or the synovial layer or articular cartilage may be exposed. When doubt exists, the wound should be enlarged. The use of the probe is to be avoided, on account of the risk of carrying infective material from the track of the wound into the joint.

Penetrating wounds of joints are treated on the same lines as compound fractures. If the penetrating instrument is to be regarded as infected,--as, for example, when the spoke of a motor bicycle is driven through the upper pouch of the knee,--the injury is to be looked upon as serious and capable of endangering the function of the joint, loss of the limb, or even life itself. Reliance is chiefly laid on primary excision of the edges and track of the wound, and other measures employed in the treatment of gun-shot wounds. While the wound in the synovialis and capsule is sutured, that in the soft parts is left open. If drainage is employed, the tube extends down to the opening in the synovialis, but not into the joint itself. If sepsis supervenes, the joint is opened and irrigated by Carrel's method. Some form of splint and a Bier's bandage are valuable adjuncts. The final recourse is to amputation.

#Gun-shot injuries# of joints vary in severity from a mere puncture of the synovial layer by a chip of shell to complete shattering of the articular surfaces. Between these extremes are cases in which the capsular and synovial layer are extensively lacerated without involvement of the bones, and others in which the bones are implicated without serious damage being done to ligaments or synovial layer--for example, by a bullet passing through and through the cancellated part of one of the constituent bones, or by a fissure extending into the articular surface.

In all degrees the great risk is from septic infection, which may be assumed to be present in all but the last-named variety.

The treatment consists in immediately cleansing the wound by excising grossly damaged tissue and removing any foreign body that may have lodged; disinfecting the exposed part of the joint cavity with eusol, "bipp," or other antiseptic, and closing the wound or establishing drainage, according to circumstances. The joint is then immobilised till the wound has healed, after which massage and movement are commenced. When the bones are shattered or when sepsis gets the upper hand and disorganises the joint, amputation is called for.

#Sprains.#--A sprain results from a stretching or twisting form of violence which causes the joint to move beyond its physiological limits, or in some direction for which it is not structurally adapted. The main incidence of the force therefore falls upon the ligaments, which are suddenly stretched or torn. The synovial layer also is torn, and the joint becomes filled with blood and synovial fluid.

Muscles and tendons passing over the joint are stretched or torn, and their sheaths filled with serous effusion. It is not uncommon for portions of bone to be torn off at the site of attachment of strong ligamentous bands or tendons, constituting a "sprain fracture"; or for intra-articular cartilages to be torn and displaced, as in the knee.

Clinical Features.--The injury is accompanied by intense sickening pain, and this may persist for a considerable time. At first it is aggravated by moving the joint, but if the movement is continued it tends to pass off. The particular ligaments involved may be recognised by the tenderness which is elicited on making pressure over them, or by putting them on the stretch. In this way a sprain may often be diagnosed from a fracture in which the maximum tenderness is over the injury to the bone.

The effusion of blood and synovia into the joint and into the tissues around gives rise to swelling and discoloration, and the fluid effused into tendon sheaths often produces a peculiar creaking sensation, which may be mistaken for the crepitus of fracture. In sprains, the bony points about the joint retain their normal relations to one another, and this usually enables these injuries to be diagnosed from dislocations. When the swelling is great, it is often necessary to have recourse to the Roentgen rays to make certain that there is no fracture or dislocation. The special features and complications of sprains of the knee are discussed with other injuries of that joint.

Repair of Sprains.--Blood and synovia are absorbed and torn structures become reunited, but in this process adhesions may form inside the joint and in the surrounding tendon sheaths and interfere with the movement of the joint.

Prognosis.--Stiffness, lasting for a longer or shorter time, follows most sprains, but may be largely prevented by proper treatment. In old and rheumatic persons, changes of the nature of arthritis deformans are liable to supervene, interfering greatly with movement. While suppuration is rare, tuberculous disease is alleged to have resulted from a sprain.

Treatment.--If seen immediately after the accident, firm pressure should be applied by means of an elastic bandage over a thick layer of cotton wool, to prevent bleeding and effusion of synovia. Later the best treatment is by massage and movement. In the ankle, for example, massage should be commenced at once, the part being gently stroked upwards. If the massage is light enough there is no pain, it is actually soothing. The rubbing is continued for from fifteen to twenty minutes, and the patient is encouraged to move the toes and ankle; a moderately firm elastic bandage is then applied. The massage is repeated once or twice a day, the sittings lasting for about fifteen minutes. The patient should be encouraged to move the joint from the first, beginning with the movements that put least strain upon the damaged ligaments, and gradually increasing the range. In the course of a few days he is encouraged to walk or cycle, or otherwise to use the joint without subjecting it to strain, or to a repetition of the movement that caused the accident. Alternate hot and cold douching, or hot-air baths, followed by massage, are also useful. Complete rest and prolonged immobilisation are to be condemned.

TRAUMATIC DISLOCATIONS

A dislocation or luxation is a persistent displacement of the opposing ends of the bones forming a joint. We are here concerned only with such dislocations as immediately follow upon injury. Those that are congenital or that result from disease will be studied later.

Causes.--The majority of dislocations are the result of indirect violence, the more movable bone acting as a lever, on a fulcrum furnished by the natural check to movement in the form of ligament, bone, or muscle. It is in this way that most dislocations of the shoulder, hip, and elbow are produced.

At the moment the violence is applied, the muscles are relaxed or otherwise taken at a disadvantage, so that the joint is for the time being deprived of their support. The joint is moved beyond its physiological range, and the end of one of the bones being brought to bear upon the capsule, tears it, and passes through the rent thus made. The muscles then contract reflexly, and pull the head of the bone into an unnatural position outside the capsule. The position assumed will depend upon such factors as the direction of the force, the structure of the joint, the position of the limb at the time of the accident, and the relative strength of the different groups of muscles acting upon the bone which is displaced.

Violence applied directly to the joint is a much less frequent cause of dislocation. In this way, however, the knee-joint may be dislocated, one bone being driven past the other--for example, by a kick from a horse; or the acromio-clavicular joint by a blow on the shoulder.

Muscular contraction is not often the sole cause of dislocation, although, as has been mentioned, it plays an important role in the production of the majority of these injuries. The shoulder, mandible, and patella are, however, not infrequently displaced by muscular action alone. Acrobats sometimes acquire the power of dislocating certain joints by voluntary contraction of their muscles.

Age and Sex.--Dislocations occur most frequently in adult males, doubtless on account of the nature of their occupations and recreations. In children the epiphyses are separated, and in old people the bones are broken by such forms of violence as cause dislocation in the middle-aged.

Muscular debility and undue laxness of ligaments resulting from disease or previous dislocation are also predisposing factors.

Clinical Varieties.--The separation between the bones may be complete or partial. When partial, portions of the articular surfaces remain in apposition, and the injury is known as a sub-luxation. Like fractures, dislocations may be simple or compound, the latter being specially dangerous on account of the risk of infection. When seen within a few days of its occurrence, a dislocation is looked upon as recent; but when several weeks or months have elapsed, it is spoken of as an old-standing dislocation. The latter will be described later.

Dislocations, like fractures, may be complicated by injuries to large blood vessels or nerve-trunks, by injuries to internal organs, or by a wound of the soft tissues which does not communicate with the joint. Further, a fracture may coexist with a dislocation--a most important complication.

Clinical Features.--The most characteristic signs of dislocation are preternatural rigidity, or want of movement where movement should naturally take place; mobility in abnormal directions; and deformity, the part being "out of drawing" as compared with the uninjured side (Fig. 18). The bony landmarks lose their normal relationship to one another; and the deformity is characteristic, and is common to all examples of the same dislocation.

Although any of the subsidiary signs may occur in lesions other than dislocations, due weight must be given to them in making a diagnosis. Loss of function is complete as a rule. Pain is much more intense than in fracture, usually because the displaced bone presses upon nerve-trunks, and from the same cause there is often numbness and partial paralysis of the limb beyond. Swelling of the soft parts due to effused blood is usually less marked in dislocation than in fracture, but is often sufficiently great to interfere with diagnostic manipulations. The displaced bone, and sometimes the empty socket, may be palpable. Discoloration is usually later of appearing than in fractures. Alteration in the length of the injured limb--usually in the direction of shortening--is a common feature; while girth measurements usually show an increase. A peculiar soft grating or creaking sensation is often felt on attempting to move the joint; this is due to cartilaginous or ligamentous structures rubbing on one another, and must not be mistaken for the crepitus of fracture. In the majority of cases, although not in all, after reduction has been effected, the bones retain their proper relations without external support, a point in which a dislocation differs from a fracture. A careful investigation of the kind of force which produced the injury, particularly as regards its intensity and direction of action, may aid in the diagnosis. The diagnosis can always be verified by the use of the Roentgen rays, and this should be had recourse to whenever possible, as a fracture may be shown that otherwise would escape recognition.

Prognosis.--After having once been dislocated, a joint is seldom as strong as it was formerly, although for all practical purposes the limb may be as useful as ever. Some degree of stiffness, of limited movement, or of muscular weakness, and occasional arthritic changes and a liability to re-dislocation, are the commonest sequelae. Prolonged immobilisation is liable to lead to stiffness by permitting of the formation of adhesions; while too early movement tends to produce a laxity of the ligaments which favours re-displacement from slight causes.

Treatment.--Reduction should be attempted at the earliest possible moment. Every hour of delay increases the difficulty. The guiding principle is to cause the displaced bone to re-enter its socket by the same route as that by which it left it--that is, through the existing rent in the capsule. This is done by carrying out certain manipulations which depend upon the anatomical arrangement of the parts, and which vary, not only with different joints, but also with different varieties of dislocation of the same joint. In general terms it may be said that the main impediments to reduction are: the contraction of the muscles acting upon the displaced bone; the entanglement of the bone among tendons or ligamentous bands which fix it in its abnormal position; and the rent in the capsule being small or valvular, so that it forms an obstacle to the bone reentering the socket.

Muscular contraction is best overcome by the administration of a general anaesthetic, and in all but the simplest cases this should be given to ensure accurate and painless reduction. Failing this, however, the muscles may be wearied out by the surgeon making steady and prolonged traction on the limb, while an assistant makes counter-extension on the proximal segment of the joint. Advantage may also be taken of such muscular relaxation as occurs when the patient is already faint, or when his attention is diverted from the injured part, to carry out the manipulations necessary to restore the bone to its normal position.

The appropriate manoeuvres for disengaging the head of the bone from tendons, ligaments, or bony processes with which it may be entangled, will be suggested by a consideration of the anatomy of the particular joint involved, and will be described with individual dislocations.

In reducing a dislocation, no amount of physical force will compensate for a want of anatomical knowledge. All tugging, twisting, or wrenching movements are to be avoided, as they are liable to cause damage to blood vessels, nerves, or other soft parts, or even--and especially in old people--to fracture one of the bones concerned.

After reduction, great benefit is gained by the systematic use of massage and movement. Before any restraining apparatus is applied the whole region should be gently stroked in a centrifugal direction for fifteen or twenty minutes; and this is to be repeated daily, each sitting lasting for about twenty minutes. From the first day onward, movement of the joint is carried out in every direction, except that which tends to bring the head of the bone against the injured part of the capsule; and the patient is encouraged to move the joint as early as possible. The appropriate apparatus and the period during which it should be worn will be considered with the individual dislocations.

Operation in Simple Dislocations.--In a limited number of cases, even with the aid of an anaesthetic, reduction by manipulation is found to be impossible. Resort must then be had to operation, which is a comparatively safe and satisfactory proceeding, although often difficult. It may happen in rare instances that the undoing of the displacement is only possible after the removal of a portion of one or other of the bones.

#Compound Dislocations.#--Compound dislocations are usually the result of extreme violence produced by machinery or railway accidents, or by a fall from a height. In the majority of cases they are complicated by fracture of one or more of the constituent bones of the joint, as well as by laceration of muscles, tendons, and blood vessels. In the region of the ankle, wrist, and joints of the thumb, however, compound dislocation is sometimes met with uncomplicated by other lesions. The great risk is infection, which may result in serious impairment of the usefulness of the joint or even in its complete destruction, results towards which the concomitant injuries materially contribute. In many instances where infection has occurred, ankylosis is the best result that can be hoped for.

Treatment.--As a rule, the first question that arises is whether amputation is necessary or not, and the considerations that determine this point are the same as in compound fractures (p. 26). If an attempt is to be made to save the limb, the treatment is the same as in compound fracture (p. 25).

#Dislocation complicated by Fracture.#--In certain dislocations the separation of small portions of bones or of epiphyses is of common occurrence--for example, fracture of the tip of the coronoid process in dislocation of the elbow backwards, and chipping off of a portion of the edge of the acetabulum in dislocation of the hip.

The most important example of a fracture complicating a dislocation is fracture of the surgical neck of the humerus coexisting with dislocation of the shoulder. Here the difficulty of diagnosis is greatly increased, and the treatment of both injuries requires to be modified. The dislocation must be reduced--by operation if necessary--before the fracture is treated, and in many cases it is advisable to secure the fragments of the broken bone by pegs, or plates, to admit of movement being commenced early, and so to prevent stiffness of the joint.

#Old-standing Dislocations.#--When, from want of recognition--and, curiously enough, a dislocation is much more liable to be overlooked than would have been thought possible--or from unsuccessful treatment, a dislocation is left unreduced, changes take place in and around the joint which render reduction increasingly difficult or impossible. The rent in the capsule closes upon the neck of the bone, and fibrous adhesions form between muscles, tendons, and other structures that have been torn. The articular cartilage of the head, being no longer in contact with an opposing cartilage, tends in time to be converted into fibrous tissue, and may become adherent to other fibrous structures in its vicinity. By pressing on adjacent structures it may form for itself a new socket of dense fibrous tissue which in time becomes lined with a secreting membrane. When the displaced head lies against a bone, the continuous pressure produces a new osseous socket, from the margins of which osteophytic outgrowths may spring, and as the surrounding fibrous tissue becomes condensed and forms a strong capsule, a new joint results. The occurrence of these changes in the direction of a new ball-and-socket joint is largely dependent on the behaviour of the patient: a vigorous man, anxious to recover the use of the limb, will employ it with a degree of determination and indifference to pain that could not be expected in a sensitive elderly female. The most perfect example of a new ball-and-socket joint, following upon an unreduced dislocation at the hip, that has come under our observation, was in a hunting dog, given one of us by an Australian pupil, who testified that the animal was as fleet with the new joint as it had been with the original one. Meanwhile the cartilage of the original socket is converted into fibrous tissue, which may come to fill up the cavity. Changes resembling those of arthritis deformans may occur. The large blood vessels and nerves in the vicinity may be pressed upon or stretched by the displaced bone, or may be implicated in fibrous adhesions. In course of time they become lengthened or shortened in accordance with the altered attitude of the limb.

In many cases the new joint is remarkably mobile and useful; but in others, pain, limited movement, and atrophy of muscles render it comparatively useless, and surgical intervention is called for.

Treatment.--It is always a difficult problem to determine the date after which it is inadvisable to attempt reduction by manipulation in an old dislocation and no rules can be laid down which will cover all cases. Rather must each case be decided on its own merits, due consideration being had to the risks that attend this line of treatment. The chief of these are: rupture of a large blood vessel or nerve that has formed adhesions with the displaced bone, or has become shortened in adaptation to the altered shape or length of the limb; tearing of muscles or tendons, or even of skin; fracture of the bone, especially in old people; and separation of epiphyses in the young.

Before carrying out the manipulations appropriate to the particular dislocation, all adhesions must first be broken down; and during the proceedings no undue force is to be employed. The first attempt at reduction may fail, and yet subsequent efforts, at intervals of a few days, may ultimately prove successful; the vigorous traction and twisting of the soft parts, matted together as they are by scar-tissue, causes reactive changes in the vessels and tissues which render them more liable to yield on subsequent attempts at reduction. In old people, and where there is an absence of suffering from pressure on nerves or vessels, it may be wiser to leave the dislocation unreduced, and strive rather by massage and movement to obtain a useful variety of false joint. If the conditions are otherwise, it may be better to improve the function of the limb by an open operation. Tight ligaments and other structures are divided, and the socket is cleared out. If reduction is still impossible, a partial excision may be performed and a flap of fascia lata introduced to prevent ankylosis (arthroplasty). In the case of the hip, the dislocation may be left alone and the femur divided below the trochanter, especially if there is pronounced flexion.

#Habitual or recurrent dislocation# is almost exclusively met with in the shoulder, and will be described with the injuries of that joint.

#Pathological Dislocations.#--Joints may become dislocated in the course of certain diseases. These pathological dislocations fall into different groups: (1) those due to gradual stretching of the capsular and other ligaments weakened by inflammatory and suppurative processes, such as sometimes follow on typhoid, scarlet fever, or diphtheria, and in pyaemia; (2) those due to destructive changes in the ligaments and bones--typically seen in tuberculous arthritis, in arthritis deformans, in Charcot's disease, and in nerve lesions, e.g. dislocation of the hip in spastic conditions, such as Little's disease; (3) those associated with deformed attitudes of the limb; (4) those due to changes in the articular surfaces, e.g. the phalanges in arthritis deformans. These will be considered with the conditions which give rise to them.

#Congenital Dislocations.#--Congenital dislocations are believed to be the result of abnormal or arrested development in utero, and are to be distinguished from dislocations occurring during birth, which are essentially traumatic in origin. They will be described along with the Deformities of the Extremities.

III. INJURIES IN THE REGION OF THE SHOULDER AND UPPER ARM

Surgical Anatomy--FRACTURES OF CLAVICLE: Varieties--DISLOCATION OF CLAVICLE: Varieties--DISLOCATION OF SHOULDER: Varieties--Sprains and contusions of shoulder--FRACTURE OF SCAPULA: Sites--FRACTURE OF UPPER END OF HUMERUS: Surgical neck; Separation of epiphysis; Fracture of head, anatomical neck, or tuberosities--FRACTURES OF SHAFT OF HUMERUS.

The injuries met with in the region of the shoulder include fractures and dislocations of the clavicle, fractures of the scapula, dislocations and sprains of the shoulder-joint, and fractures of the upper end of the humerus.

#Surgical Anatomy.#--For the examination of an injury in the region of the shoulder the patient should be seated on a low stool or chair. After inspecting the parts from the front, the surgeon stands behind the patient and systematically examines by palpation the shoulder girdle and upper end of the humerus. The uninjured side should be examined along with the other for purposes of comparison.

Immediately lateral to the supra-sternal notch, the sterno-clavicular articulation may be felt, the large end of the clavicle projecting to a varying degree beyond the margins of the small and shallow articular surface on the sternum. Any dislocation of this joint is at once recognised. The clavicle being subcutaneous throughout its whole length, any irregularity in its outline can be easily detected. A small tubercle (deltoid tubercle) which frequently exists near the acromial end is liable to suggest the presence of a fracture. The lateral end forms with the acromion the acromio-clavicular joint, which, however, is not always readily identified. The fingers are now carried over the acromion, which often exhibits in the situation of its epiphysial cartilage a prominent ridge, which must not be mistaken for a fracture. The tip of the acromion is usually employed as a fixed point in measuring the length of the upper arm.

The outline of the spine of the scapula can be traced back to the vertebral border; and the body of the bone may be manipulated, and its movements tested by moving the arm.

The coracoid process can be recognised in the upper and lateral angle of the triangular depression bounded by the pectoralis major, the deltoid, and the clavicle.

The head and surgical neck of the humerus may now be felt from the axilla, if the axillary fascia is relaxed by bringing the arm to the side. The great tuberosity can be indistinctly felt on the lateral aspect of the shoulder through the fibres of the deltoid. It lies vertically above the lateral epicondyle, and may be felt to rotate with the shaft. The inter-tubercular (bicipital) groove looks forward, and lies in a line drawn vertically through the biceps muscle.

The subclavian artery, with its vein to the median side and the cords of the brachial plexus to the lateral side, passes under the middle of the clavicle, and may be compressed against the first rib immediately above this bone.

FRACTURE OF THE CLAVICLE

Fracture of the clavicle is one of the commonest injuries met with in practice. As about one-third of the cases occur in children, the fracture is often of the greenstick variety. The fractures are seldom compound or complicated, unless as a result of gun-shot injuries; but occasionally one of the fragments pierces the skin, or comes to press upon the subclavian vessels or the cords of the brachial plexus, arresting the pulsation in the vessels of the limb, and causing severe pain in the arm.

The most common site of fracture is in the middle third (Fig. 13), and this usually results from indirect violence, such as a fall on the outstretched hand, the elbow, or the outer aspect of the shoulder, the force being transmitted through the glenoid cavity to the scapula, and thence by the coraco-clavicular ligaments to the clavicle. The violence is therefore of a twisting character, and the bone gives way near the junction of the lateral and middle thirds, just where the two natural curves of the bone meet, and where the supporting muscular and ligamentous attachments are weakest.

The fracture so produced is usually oblique from above, downwards and inwards. The sternal fragment may be slightly drawn upwards by the clavicular fibres of the sterno-mastoid, while the acromial fragment falls by the weight of the arm, and the fragments usually overlap to the extent of about half an inch. The shoulder, having lost the buttressing support of the clavicle, falls in towards the chest wall, narrowing the axillary space, while the weight of the arm pulls it downward, and the muscles inserted in the region of the bicipital groove pull it forward.

Fracture of the middle third may result also from a direct stroke, such as the recoil of a gun, or from violent muscular contraction, the fracture as a rule being transverse, and the displacement less marked than in fracture by indirect violence.

Clinical Features.--The attitude of the patient is characteristic: the elbow is flexed and is supported by the opposite hand, while the head is inclined towards the affected shoulder to relax the muscles of the neck. Crepitus is elicited on bracing back the shoulders, or on attempting to raise the arm beyond the horizontal, and these movements cause pain. Tenderness is elicited on making pressure over the seat of fracture, and also on distal pressure. The sternal fragment almost invariably overrides the acromial, and can usually be palpated through the skin; on measurement, the clavicle is found to be shortened. When the fracture is incomplete (greenstick) or transverse, the symptoms are less marked.

Fracture of the lateral or acromial third of the clavicle is a common form of accident at football matches, and usually results from direct violence, the bone being driven down against the coracoid process, and broken as one breaks a stick over the knee. The fracture may take place through the attachment of the conoid and trapezoid ligaments, in which case the only symptoms are pain and tenderness at the seat of fracture, with impaired movement of the limb. Displacement and crepitus are prevented by the splinting action of the ligaments.

When the break is lateral to the attachment of the trapezoid ligament, the fracture is usually transverse, and is almost always due to a fall on the back of the shoulder--the angle between the spine and the acromion process striking the ground. The acromial fragment rotates forward (Fig. 14), sometimes even to a right angle, causing the tip of the shoulder to pass forwards, and so to lie slightly nearer the middle line. The integrity of the coraco-clavicular ligaments prevents any marked drooping of the shoulder. It is noteworthy that the displacement is not always evident at first.

Fractures of the medial or sternal third are rare, are usually oblique, and result either from an indirect force acting in the line of the clavicle, or, less frequently, from direct violence or muscular action. As a rule, the deformity is insignificant, except when the costo-clavicular ligament is torn, in which case the medial end of the distal fragment is tilted up by the weight of the arm. The shoulder passes downwards, forwards, and medially. When close to the sternal end, this fracture may simulate a dislocation of the sterno-clavicular joint or a separation of the clavicular epiphysis. This last is a rare accident, which may occur between the seventeenth and the twenty-fifth years, and is usually the result of violent muscular action. It differs from the other injuries in this region in being more easily reduced and retained in position, the epiphysis lying entirely within the limits of the articular capsule of the sterno-clavicular joint.

Simultaneous fracture of both clavicles usually results from a severe transverse crush of the upper part of the thorax or from a fall on the outstretched hands--for example, in hunting. The middle third of the bone is implicated, and there is marked displacement and overriding. The patient is rendered helpless, and from the extrinsic muscles of respiration being thrown out of action and the weight of the powerless limbs pressing on the chest, there is considerable difficulty in breathing, and this is often increased by the fracture being complicated by injuries of the lung or pleura.

The prognosis as to union in all these injuries is good. Firm bony union usually occurs within twenty-one days. Non-union, false-joint, or fibrous union is but rarely met with. At the same time it is to be borne in mind that, in spite of all precautions, some deformity and shortening may result, without, however, interfering with the usefulness of the limb.

Treatment.--The displacement in complete fractures of the clavicle is readily reduced by supporting the elbow, bracing back the shoulders, and levering out the tip of the affected shoulder. In a few cases the interposition of some fibres of the subclavius muscle between the fragments has prevented perfect reduction.

In the greenstick variety the bone may be bent back into its normal position, but no great force should be employed, as, in spite of imperfect reduction, the clavicle usually straightens as it grows, and although some deformity may persist, the function of the limb is not interfered with.

Recumbent Position.--There is little doubt that the most perfect aesthetic results are obtained by treating the patient in the recumbent position. In girls, therefore, in whom it is desired that the shoulders should be perfectly symmetrical, the best results are obtained from placing the patient on a firm mattress, with a narrow, firm cushion between the shoulder-blades, so that the weight of the shoulder may carry the acromial fragment laterally and backwards. A pad is inserted in the axilla, the elbow raised, and the arm placed by the side on a pillow and steadied with sand-bags. Massage is applied daily. As this position must be maintained uninterruptedly for two or three weeks, it proves too irksome for most patients. When both clavicles are fractured, however, it is, short of operation, the only available method of treatment.

In ordinary cases the arm should be placed in that position which gives the best alignment of the fragments and least deformity. A thin layer of wool is placed in the axilla to separate the skin surfaces. A sling, supporting the elbow, is now applied, maintaining the arm in position, and a body bandage fixes the arm to the side. Massage and movement should be commenced at once.

A simple method, which yields satisfactory results, is that suggested by Wharton Hood. The fracture having been reduced, three strips of adhesive plaster, each an inch and a half wide, are applied from a point immediately above the nipple to a point 2 inches below the angle of the scapula (Fig. 15). The middle strap covers the seat of fracture, and is applied first: the others, slightly overlapping it, extend about half an inch on either side. The elbow is supported in a sling. This plan has the advantage that it permits of movement of the shoulder being carried out from the first, but the plaster rather interferes with massage.

The Handkerchief Method.--In cases of emergency, one of the best methods applicable to all fractures of the clavicle is to brace back the shoulders by means of two padded handkerchiefs, folded en cravate, placed well over the tips of the shoulders and tied, or interlaced, between the scapulae. The forearm is then supported by a third handkerchief applied as a sling, the base of which is placed under the elbow, the ends passing over the sound shoulder.

Operative treatment may be called for in compound or comminuted fractures when the fragments have injured, or are likely to injure, the subclavian vessels or the cords of the brachial plexus, or when it is otherwise impossible to reduce the fracture or to retain the fragments in apposition. It is also indicated in some cases of fracture of both clavicles.

These various methods of treatment are not equally applicable to all cases. In our experience, in the circumstances indicated, the following methods have proved the most satisfactory: (1) As a temporary means of retention in emergency cases,--for example, accidents occurring on the football field,--the handkerchief method. (2) In uncomplicated fractures of average severity in any part of the bone, the method of sling and body bandage. (3) In cases where, for aesthetic reasons, the chief consideration is the avoidance of deformity and the maintenance of the symmetry of the shoulders, as in girls, the treatment by recumbency. (4) When retentive apparatus fails, or when the fragments are exerting injurious pressure, operative treatment.

In quite a number of cases, there is an excessive amount of pain, preventing sleep; where this is due to cramp-like contractions of the muscles and movements of the fragments, it is relieved by more accurate fixation, as by strips of plaster; otherwise a hypodermic injection of heroin or morphin is indicated.

DISLOCATION OF THE CLAVICLE

Dislocation of the #acromial end#--sometimes, and perhaps more correctly, spoken of as dislocation of the scapula--is more frequent than that at the sternal end, and it usually results from a blow from behind, or from a fall on the tip of the shoulder, driving down the scapula, so that the clavicle projects upwards and overrides the acromion process.

Downward displacement of the acromial end of the clavicle is much rarer, and may follow a fall on the elbow or a blow over the clavicle. The end of the bone lies under the acromion process, in contact with the capsule of the shoulder-joint, and the acromion stands out prominently.

The clinical features are so well marked that the diagnosis is unmistakable. The head inclines towards the affected side, and the tip of the shoulder tends to pass slightly downward, forward, and medially. The displaced end of the bone can be seen and felt as a prominence under the skin, or the empty socket can be palpated, while the muscles attached to the displaced clavicle stand out in relief. The movements at the shoulder are restricted, particularly in the direction of abduction above the level of the shoulder. These injuries are sometimes associated with fracture of the ribs, a complication which adds materially to the difficulties of treatment.

Treatment.--Reduction is easily effected by bracing back the shoulders and replacing the bone in its socket by manipulation; but retention is invariably difficult, and in many cases impossible; even when the displacement is permanent, however, the usefulness of the arm is not necessarily impaired.

Treatment is similar to that for fracture of the clavicle by sling and body bandage. Another plan is to place a pad over the acromial end of the clavicle, and fix it in this position by a few turns of elastic bandage carried over the shoulder and under the elbow. The forearm is placed in a sling with the elbow well supported, and the arm is bound to the side by a circular bandage. When the bone cannot be kept in position and the usefulness of the limb is impaired, the joint surfaces may be rawed and the bones wired, with a view to obtaining ankylosis.

#The sternal end# may be dislocated forwards, backwards, or upwards.

Forward dislocation is the most common; the end of the clavicle lies on the front of the sternum, somewhat below the level of the sterno-clavicular joint, and its articular surface can be distinctly palpated (Fig. 16). The inter-articular cartilage sometimes remains attached to one bone, sometimes to the other; the rhomboid ligament is usually intact.

In the backward dislocation the end of the clavicle lies behind the manubrium sterni and the muscles attached to it; there is a marked hollow in the position of the joint, and the facet on the sternum can be felt. In a comparatively small number of cases the bone exerts pressure upon the trachea and oesophagus, producing difficulty in breathing and swallowing. It has also been known to press upon the subclavian artery and on other important structures at the root of the neck.

In rare cases the rhomboid ligament is torn, and the end of the clavicle passes upwards, and rests in the episternal notch behind the sterno-mastoid muscle.

The bone may be retained in position by keeping the shoulders braced back by a figure-of-eight bandage, or by padded handkerchiefs, and making pressure over the displaced end of the bone with a pad. The forearm is supported by a sling, and the arm fixed to the side. Massage is employed from the first, and the patient is allowed to move the arm by the end of a week. Imperfect reduction interferes so little with the functions of the limb that operative measures are seldom required except for aesthetic reasons.

Dislocation of #both ends# of the clavicle has occasionally occurred from a severe crush. The ultimate result has been satisfactory, as one or other end has always healed in normal position, and the function of the arm has thus been maintained.

DISLOCATION OF THE SHOULDER

The shoulder is more frequently dislocated than all the other joints in the body taken together. This is explained by its exposed position, the wide range of movement of which it is capable, the length of the lever afforded by the humerus, and the anatomical construction of the joint--the large, round humeral head imperfectly fitting the small and shallow glenoid cavity, and the ligaments being comparatively lax and thin. The capsule of the joint is materially strengthened in its upper and back parts by the tendons of the supra- and infra-spinatus and teres minor muscles; while it is weakest below and in front, between the subscapularis and teres major tendons. It is here that it most frequently gives way and allows of the escape of the head of the bone. The determining factor is probably that when the arm is abducted the neck of the humerus comes in contact with the tip of the acromion, and further abduction forces the head against the lower, weak portion of the capsule, which gives way.

The violence is usually transmitted from the hand or elbow, less frequently from the lateral aspect of the shoulder, the limb being usually abducted and the muscles relaxed and taken unawares. The head of the humerus, thus brought to bear on the weakest part of the capsule, ruptures it and passes out through the rent. Dislocation is readily produced in an unconscious person--as, for example, in conducting artificial respiration in a patient suffering from opium poisoning, the arms being hyper-abducted to exert traction on the chest.

Varieties.--Several varieties of dislocation are recognised, according to the position in which the head of the humerus finally rests (Fig. 17). The simplest of these is the sub-glenoid variety, in which the head rests on the long tendon of the triceps, where it arises from the axillary border of the scapula just below the glenoid cavity. In almost all dislocations of the shoulder the head of the bone is at least momentarily in this position, but the sharp edge of the scapula and the rounded head are ill adapted to one another, and the position is not long maintained. The subsequent course taken by the humerus depends upon the nature and direction of the force, the position of the limb at the moment of injury, and the relative strength and capacity for effective action of the different groups of muscles acting upon the bone.

In the great majority of cases it passes forward and medially, and comes to lie against the anterior surface of the neck of the scapula, under cover of the tendons of origin of the biceps and coraco-brachialis muscles, constituting the sub-coracoid dislocation. Much less frequently it passes under cover of the pectoralis minor and against the edge of the clavicle--the sub-clavicular variety. In rare cases the head passes backward and lies against the spine on the dorsum of the scapula, beneath the infra-spinatus muscle--the sub-spinous variety. Other varieties are so rare that they do not call for mention.

Clinical Features common to all Varieties.--Dislocation of the shoulder is commonest in adult males; in advanced life the proportion of female sufferers increases. It is usually attended with great pain, and there is often numbness of the limb due to pressure of the head of the bone upon the large nerve-trunks. There is sometimes considerable shock. The patient inclines his head towards the injured side, and, while standing, the forearm is supported by the hand of the opposite side. The acromion process stands out prominently, the roundness of the shoulder giving place to a flattening or depression immediately below it, so that a straight-edge applied to the lateral aspect of the limb touches both the acromion and the lateral epicondyle. The vertical circumference of the shoulder is markedly increased; this test is easily made with a piece of tape or bandage and is compared with a similar measurement on the normal side--we lay great stress on this simple measure, as it is a most reliable aid in diagnosis. The head of the bone can usually be felt in its new position, and the axis of the humerus is correspondingly altered, the elbow being carried from the side--forward or backward according to the position of the head. The empty glenoid may sometimes be palpated from the axilla. In most cases, although not in all, the patient is unable at one and the same time to bring his elbow to the side and to place his hand upon the opposite shoulder (Dugas' symptom). Measurements of the length of the limb from acromion to lateral epicondyle are rarely of any diagnostic value.

The #sub-coracoid dislocation# (Fig. 18) is that most frequently met with. It usually results from hyper-abduction of the arm while the scapula is fixed, as in a fall on the medial side of the elbow when the arm is abducted from the side. The surgical neck of the humerus is then brought to bear upon the under aspect of the acromion, which forms a fulcrum, and the head of the bone is pressed against the medial and lower part of the capsule. In some cases muscular action produces this dislocation; it may also result from force applied directly to the upper end of the humerus.

The head leaves the capsule through the rent made in its lower part, and, either from a continuation of the force or from contraction of the muscles inserted into the inter-tubercular (bicipital) groove, particularly the great pectoral, passes medially under cover of the biceps and coraco-brachialis till it comes to rest against the anterior surface of the neck of the scapula, just below the coracoid process. The anatomical neck of the humerus presses against the anterior edge of the glenoid, and there is frequently an indentation fracture of the head of the humerus where the two bones come into contact (F. M. Caird). The subscapularis is bruised or torn, the muscles inserted into the great tuberosity are greatly stretched, or the tuberosity itself may be avulsed, allowing the long tendon of the biceps to slip laterally, where it may form an impediment to reduction. The axillary (circumflex) nerve is often bruised or torn, and the head of the humerus is liable to press injuriously on the nerves and vessels in the axilla.

The clinical features common to all dislocations are prominent, although Dugas' symptom is not constant.

Treatment.--The guiding principle in the reduction of these dislocations is to make the head of the bone retrace the course it took in leaving the socket. The main obstacles to reduction being muscular contraction and the entanglement of the head with tendons, ligaments, or bony points, appropriate means must be taken to counteract each of these factors.

A general anaesthetic is an invaluable aid to reduction, and should be given unless there is some reason for withholding it. It is specially indicated in strong muscular subjects, and in nervous patients who do not bear pain well, and particularly when the dislocation has existed for a day or two. In quite recent cases, however, the surgeon may succeed in replacing the bone by taking advantage of a temporary faintness, or by engaging the patient's attention with other matters while he carries out the appropriate manipulations.

When an anaesthetic is employed, the patient should be laid on a mattress on the floor, or on a narrow, firm table; otherwise he should be seated on a chair.

Kocher's method is suitable for the great majority of cases of sub-coracoid dislocation. (1) The elbow is firmly pressed against the side, and the forearm flexed to a right angle. The surgeon grasps the wrist and elbow and firmly rotates the humerus away from the middle line (Fig. 20) till distinct resistance is felt and the deltoid becomes more prominent. In this way the rent in the lower part of the capsule is made to gape, and the head of the humerus rolls away from the middle line till it lies opposite the opening, rotation taking place about the fixed point formed by the contact of the anatomical neck of the humerus with the anterior lip of the glenoid cavity (D. Waterston). (2) The elbow is next carried forward, upward, and towards the middle line (Fig. 21); the humerus acting as the long arm of a lever on the fulcrum furnished by the muscles inserted in the region of the surgical neck, the head, which forms the short arm of the lever, is carried backward, downward, and laterally, and is thus directed towards the socket. (3) The humerus is now rotated towards the middle line by carrying the hand across the chest towards the opposite shoulder (Fig. 22). The anatomical neck of the humerus is thus disengaged from the edge of the glenoid, and the head is pulled into the socket by the tension of the surrounding muscles.

A method of reduction has been formulated by A. G. Miller, which we have found to be quite as successful as Kocher's method. The limb is grasped above the wrist and elbow, the forearm flexed to a right angle, and the upper arm abducted to the horizontal (Fig. 23). While an assistant makes counter-extension and fixes the scapula, the surgeon gradually draws the arm away from the body till the head of the humerus is felt to pass laterally. The humerus is then rotated medially by dropping the hand (Fig. 24), and the bone gradually glides into the socket.

In a certain number of cases reduction can be effected by hyper-abduction of the shoulder with traction. The patient is laid upon a firm mattress, and the surgeon, seated behind him while an assistant fixes the acromion, slowly and steadily extends the arm until it is raised well above the head. In some cases the head of the humerus spontaneously slips into its socket; in others it may be manipulated into position by pressure from the axilla. This method is restricted to recent cases, as in those of long standing the axillary vessels are liable to be stretched or torn.

The method of reduction by traction on the arm with the heel in the axilla is only to be used when other measures have failed, as it depends for its success on sheer force.

After-Treatment.--After reduction, the part is gently massaged for ten or fifteen minutes, a layer of wool is placed in the axilla, the forearm is supported by a sling, and the arm fixed to the side by a circular bandage. Massage is carried out from the first, and movement of the shoulder in every direction except that of abduction may be commenced on the first or second day. The circular bandage may be dispensed with at the end of a week, and abduction movements commenced, and by the end of a month the patient should be advised to use the arm freely.

The #sub-clavicular dislocation# (Fig. 17) is to be looked upon as an exaggerated degree of the sub-coracoid rather than as a separate variety. It is produced by the same mechanism, but the violence is greater, and the damage to the soft parts more severe. The head passes farther upwards and towards the middle line under cover of the pectoralis minor, resting under the clavicle against the serratus anterior and chest wall. The symptoms are usually so marked that they leave no doubt as to the diagnosis. The outline of the head of the humerus in its abnormal position is visible through the skin, and the shortening of the limb is more marked than in the sub-coracoid variety. The treatment is the same as for sub-coracoid dislocation.

#Sub-glenoid dislocation# (Fig. 17) is less frequently met with than the sub-coracoid variety, and almost always results from forcible abduction of the arm. The head of the humerus passes out through a small rent in the lower and medial portion of the capsule, and rests against the anterior edge of the triangular surface immediately below the glenoid cavity, supported behind by the long head of the triceps, and in front by the subscapularis muscle. It is readily felt in the axilla. All the tendons in relation to the upper end of the humerus are stretched or torn, and the great tuberosity is not infrequently avulsed. There is sometimes bruising of the axillary nerve.

The projection of the acromion, the flattening of the deltoid, the increased depth of the axillary fold, and the abduction of the elbow are well marked; the arm is slightly lengthened, rotated out, and carried forward. It is reduced by the hyper-abduction method (p. 60).

#Sub-spinous Dislocation.#--Backward dislocation is usually termed sub-spinous, although in a considerable proportion of cases the head of the humerus does not pass beyond the root of the acromion process (sub-acromial) (Fig. 17). This dislocation is usually produced by a fall on the elbow, the arm being at the moment adducted and rotated medially, so that the head of the humerus is pressed backwards and laterally against the capsule, which ruptures posteriorly. All the muscles attached to the upper end of the humerus are liable to be torn, and the tuberosities are frequently avulsed. The long tendon of the biceps may slip from its position between the tuberosities, and prevent reduction or favour re-dislocation, necessitating an open operation.

In the milder cases the clinical features are not always well marked, and on account of the swelling this dislocation is apt to be overlooked. In addition to the ordinary symptoms, the shoulder is broadened, there is a marked hollow in front in which the coracoid projects, and the arm is held close to the side with the elbow directed forward. The head of the bone may be seen and felt in its abnormal position below the spine of the scapula.

Reduction can usually be effected by making traction on the arm with medial rotation, and pressing the head forward into position, while counter-pressure is made upon the acromion.

Prognosis.--The ultimate prognosis in dislocations of the shoulder should always be guarded. The axillary nerve may be stretched or torn, and this may lead to atrophy of the deltoid; or other branches of the brachial plexus may be injured and the muscles they supply permanently weakened. In a certain number of cases traumatic neuritis has resulted in serious disability of the limb. The movements of the shoulder-joint may be restricted by cicatricial contraction of the torn portion of the capsule and of the damaged muscles. A marked tendency to recurrent dislocation may follow if abduction movements are permitted before repair of the capsule has had time to occur.

#Dislocation of the Shoulder complicated with Fracture of the Upper End of the Humerus.#--In these injuries the dislocation is almost always of the sub-coracoid variety, and the most common fractures by which it is complicated are those of the surgical neck, the anatomical neck, or the greater tuberosity. The most common cause is a fall directly on the shoulder, and it seems probable that the head of the bone is first dislocated, and, the force continuing to act, the upper end of the humerus is then broken; or the two lesions may be produced synchronously.

When seen soon after the accident, the existence of the fracture of the humerus is liable to be overlooked, the condition being mistaken for dislocation alone, or for a fracture through the neck of the scapula. On careful examination under an anaesthetic, however, it is observed that not only is the head of the humerus absent from the glenoid cavity, but that it does not move with the rest of the bone, abnormal mobility and crepitus are recognised at the seat of fracture, and the upper arm is shortened. The extravasation in the axilla is usually greater than that accompanying a simple dislocation, and the pain and shock are more severe. A fracture through the neck of the scapula alone is readily recognised by the ease with which the deformity is reduced, and the way in which it at once recurs when the support is withdrawn. In many cases it is only by the aid of a radiogram that an accurate diagnosis can be made (Fig. 25).

Treatment.--Unless the dislocation is reduced at once, the movements of the arm are certain to be seriously restricted, and painful pressure effects from excess of callus are liable to ensue. An attempt should first be made, under anaesthesia, to replace the head in its socket, by making extension on the arm in the hyper-abducted (vertical) position, and manipulating the upper fragment from the axilla.

On no account should the lower fragment be employed as a lever in attempting reduction. When reduction by manipulation fails, recourse should be had to an open operation. The upper fragment should be exposed by an incision over its lateral aspect, and made to return to the socket by using Arbuthnot Lane's levers or M'Burney's hook, or a long steel pin may be inserted into the fragment to give the necessary leverage.

Reduction having been accomplished, the fracture is adjusted in the usual way, advantage being taken of the open wound, if necessary, to fix the fragments together by plates. The best position in which to fix the limb is that of abduction at a right angle. Massage and movement should be commenced early to prevent stiffness of the joint.

When it is found impossible to reduce the dislocation, it is usually advisable to remove the upper fragment.

The method of allowing the fracture to unite without reducing the dislocation, and then attempting reduction, usually results in re-breaking the bone, or else in failure to replace the head in the socket, and has nothing to recommend it.

#Old-standing Dislocation of the Shoulder.#--It is impossible to lay down definite rules as to the date after which it is inadvisable to attempt reduction by manipulation of an old-standing dislocation of the shoulder. Experience of a hundred cases in Bruns' clinic led Finckh to conclude that, provided there are no complications, reduction can generally be effected within four weeks of the accident; that within nine weeks the prospect of success is fairly good; but that beyond that time reduction is exceptional.

The patient is anaesthetised, and all adhesions broken down by free yet gentle movement of the limb. The appropriate manipulations for the particular dislocation are then carried out, care being taken that no undue force is employed, as the humerus is liable to be broken. If these are not successful, they should be repeated at intervals of two or three days, as it is frequently found that reduction is successfully effected on a second or third attempt.

Should manipulative measures fail, it may be advisable to have recourse to operation if the age of the patient and his general health warrant it, and if the condition of the limb is interfering with his occupation or involves serious disability. If operation is deemed advisable, a few days should be allowed to elapse to permit of the parts recovering from the effects of the manipulations. The joint is freely exposed, the capsule divided, the head of the bone freed and returned to the glenoid cavity. It is sometimes so difficult to replace the head of the bone that it is necessary to resect it and aim at the formation of a new joint, an operation which usually yields satisfactory results.

#Habitual or Recurrent Dislocation.#--Cases are occasionally met with in which the shoulder-joint shows a marked tendency to be dislocated from causes altogether insufficient to produce displacement under ordinary circumstances. This condition is usually met with in young women, and, in some cases at least, appears to be due to too early and too free movement of the joint after an ordinary dislocation, so that the capsule is stretched and remains lax. In some cases it would appear that the liability to dislocation is due to some structural defect in the joint, and under these conditions both sides are sometimes affected, and the accident is not attended with the usual pain and disability either at the time or after reduction. The facility and frequency with which dislocation recurs render the limb comparatively useless, and may seriously incapacitate the patient. We have had cases under observation in which dislocation resulted from the hyper-abduction of the arm in swimming, from throwing the arms above the head in dancing and in gymnastic exercises, and even in "doing" the hair.

The treatment consists in preventing the patient making the particular movements which tend to produce the dislocation. These are chiefly movements of hyper-abduction and overhead movements; we have found an apparatus consisting of a belt applied around the thorax, and fixed to another around the upper arm by a band which passes above the axillary fold of the dress, useful in restraining these movements. If these measures fail, it may be advisable to have recourse to operation; this may consist in tightening up the capsule, the results of which are said to be uncertain, or in detaching a portion of the deltoid or subscapularis muscle and stitching it beneath the joint to cover and strengthen the weakened portion of the capsule. It is suggestive that in performing this operation no rent in the capsule is discovered.

The condition is also met with in epileptics; and it is generally found that the head of the bone is deficient, as a result either of fracture or disease; that the muscles which naturally support the joint are atrophied or torn; and that the capsule is unduly lax.

#Sprain# of the shoulder-joint is comparatively rare, because of the wide range of movement of which it is capable. The region of the shoulder becomes swollen and tender to pressure, the point of maximum tenderness being over the front of the joint, just below the acromion process; pain is elicited also when the ligaments or tendons are put upon the stretch.

#Contusion# of the region of the shoulder, on the other hand, is exceedingly common. In most cases it is merely the deltoid muscle and the subcutaneous tissue over it that are bruised, but sometimes a haematoma forms either in the muscle or in the sub-deltoid bursa. There is pain on moving the limb, and the patient may be unable to abduct the arm at the shoulder-joint. Under treatment by massage and movement, the symptoms usually pass off completely in two or three weeks. The affections of the bursa are described elsewhere.

In other cases, the cords of the brachial plexus above the clavicle are stretched, or the axillary nerve is bruised, and these injuries are liable to be followed by prolonged pain, loss of abduction, and stiffness in the arm. The deltoid frequently undergoes considerable atrophy, and there is severe neuralgic pain in the axillary nerve, especially marked in the region of the insertion of the deltoid.

In addition to maintaining the limb in the abducted position, it is necessary to keep up the nutrition of the muscles by massage and electricity.

FRACTURE OF THE SCAPULA

Fractures of the scapula may implicate the body, the surgical neck, the acromion, or the coracoid process. They are rarely compound.

#Fracture of the Body.#--Considering its exposed position, the body of the scapula is comparatively seldom fractured, doubtless because of its mobility, and the support it receives from the elastic ribs and soft muscular cushions on which it lies. Apart from gun-shot injuries, it is most frequently broken by a severe blow or crush. The scapula presents two natural arches--one longitudinal, the other transverse--and when the bone is crushed or struck, the force produces fracture by undoing its curves (E. H. Bennett). A main fissure usually runs transversely across the infra-spinous fossa, and secondary cracks radiate from it (Fig. 26). In other cases the line of the primary fracture is longitudinal, passing through the spine and involving both fossae.

The clinical features are obscured by swelling of the overlying soft parts. Crepitus may sometimes be elicited by placing one hand firmly over the bone, and with the other moving the arm and shoulder. When the spine is implicated, the fragments may be grasped and made to move one upon another. The displacement, which usually consists in overlapping of the fragments--although sometimes they are drawn apart--is partly due to the action of the serratus anterior and teres major muscles, and partly depends on the direction of the force. Movement is restricted and painful. Osseous union usually takes place rapidly, and although displacement often persists, the function of the limb is unimpaired.

Treatment.--As these fractures are usually complicated by other injuries, especially of the thorax, and are accompanied by severe shock, it is necessary to confine the patient to bed. It is usually sufficient to fix the arm and shoulder to the chest wall by a firm binder, in the position which admits of the most complete apposition of fragments. This retentive apparatus is employed for about three weeks, after which the patient is allowed to use his arm. The bandages are removed daily to admit of massage.

#Fracture of the surgical neck of the scapula#, although a rare accident, is of importance, as it is liable to be mistaken for dislocation of the shoulder. The line of fracture runs through the scapular notch, downwards and laterally to the lower margin of the glenoid, so that the glenoid and the coracoid process are separated from the rest of the bone.

The coraco-acromial and coraco-clavicular ligaments are usually torn, and the detached fragment, along with the head of the humerus, sinks into the axilla, causing a flattening of the shoulder, and leaving a depression below the projecting acromion. These signs may be obscured by the general swelling of the shoulder. The arm may be lengthened about an inch. By supporting the arm the deformity is at once reduced, but recurs as soon as the support is withdrawn. Crepitus is usually detected on carrying out this manipulation; and the coracoid process is found to move with the arm and not with the scapula. By these tests, and by the X-rays, this injury is distinguished from a dislocation.

A partial fracture carrying away the lower part of the glenoid cavity simulates a sub-glenoid dislocation. This is, however, a rare injury.

The treatment consists in bracing back the shoulders and supporting the elbow, and this is most satisfactorily done by a body bandage and sling for the elbow, as for fracture of the middle third of the clavicle. Passive movements and massage are employed from the first.

#Fracture of the acromion process# may result from a blow or fall on the shoulder. It is often overlooked on account of the swelling resulting from bruising of the soft parts, and the absence of marked displacement. On palpation, crepitus and an irregularity at the seat of fracture may sometimes be detected. The shoulder is slightly flattened, and abduction of the arm is difficult. In rare cases the fracture passes into the acromio-clavicular joint, and is associated with dislocation of the clavicle.

In connection with this fracture, reference must be made to a condition frequently met with, in which the epiphysial portion of the acromion is found to be separate from the body of the process--separate acromion. This is by some (Symington, Hamilton) looked upon as a want of union of the epiphysis, but the weight of evidence seems to prove that it is rather of the nature of an un-united fracture at this level, even when, as sometimes happens, it is bilateral (Struthers, Arbuthnot Lane).

Between the fourteenth and twenty-second years a true separation of the epiphysis may be met with, but it is seldom possible to make a positive diagnosis of this injury. As is the case in all fractures of the acromion, bony union seldom takes place.

The treatment is the same as for fracture of the lateral end of the clavicle.

#Fracture of the coracoid process# is rare. It may result from direct violence, such as the recoil of a gun, but it is more often an accompaniment of dislocation of the shoulder or of the lateral end of the clavicle upward. As the coraco-clavicular ligaments usually remain intact, there is no displacement; but when these are torn the coracoid is dragged downwards and laterally by the combined action of the pectoralis minor, biceps, and coraco-brachialis muscles. Crepitus may be elicited on moving the fragment. Separation of the epiphysial portion of the coracoid may occur up to the seventeenth year.

The treatment consists in placing the arm across the front of the chest, to relax the muscles causing the displacement, and retaining it in that position by a sling and roller bandage.

FRACTURE OF THE UPPER END OF THE HUMERUS

It is most convenient to study fractures of the upper end of the humerus in the following order: (1) fracture of the surgical neck; (2) separation of the epiphysis; (3) fracture of head, anatomical neck, or tuberosities.

#Fracture of the Surgical Neck.#--The surgical neck of the humerus extends from the level of the epiphysial junction to the insertion of the pectoralis major and teres major muscles, and it is within these limits that most fractures of the upper end of bone occur. This fracture is most common in adults, and usually follows direct violence applied to the shoulder, but may result from a fall on the hand or elbow, or from violent muscular action, as, for example, in throwing a stone. It is usually transverse, and there is often little or no displacement, the fragments being retained in position by the long tendon of the biceps and the long head of the triceps. When the fracture is oblique, the fragments are often comminuted, and sometimes impacted. The displacement of the upper fragment seems to depend upon the attitude of the limb at the moment of fracture. When the upper arm is approximated to the side, the upper fragment retains its vertical position, but is slightly rotated laterally by the muscles inserted into the greater tuberosity, while the lower fragment is drawn upwards and medially towards the coracoid process by the muscles inserted into the inter-tubercular groove and the longitudinal muscles of the upper arm, and can be felt in the axilla. The elbow points laterally and backwards, and the upper arm is shortened. The shoulder retains its rotundity, but there is a slight hollow some distance below the acromion. On grasping the elbow and moving the shaft, it is found that the head and tuberosities do not move with it, and unnatural mobility and crepitus at the seat of fracture may be detected. When the upper arm is abducted at the moment of fracture, the upper fragment is retained in that position by the lateral rotator and abductor muscles inserted into it, while the lower fragment passes upwards and medially.

Although there is sometimes overlapping and broadening after union, beyond some limitation of the range of abduction the usefulness of the limb is seldom impaired.

Treatment.--Massage, by allaying spasm of the muscles, soon overcomes the moderate amount of displacement which is usually met with. Further, the skin surfaces of the axilla having been separated by a thin layer of cotton wool, a sling is applied to support the wrist, and the arm is bound to the side by a body bandage.

In comminuted fractures and those with marked displacement, a general anaesthetic may be required to ensure accurate reduction; and to maintain the fragments in apposition, and to avoid any limitation of abduction after union, the limb may be fixed in the position of abduction at a right angle by means of a Thomas' arm splint with swivel ring, and extension applied, if necessary, to maintain this attitude. After a week or ten days the patient is allowed up, wearing an abduction frame (Fig. 29), or a splint, such as Middeldorpf's, which consists of a double inclined plane, the base of which is fixed to the patient's side, while the injured arm rests on the other two sides of the triangle. Massage and movement are employed daily.

Should these measures fail, the fracture may be exposed by an incision carried along the anterior border of the deltoid, and the ends mechanically fixed, after which the limb is put up in the abducted position for three or four weeks. Massage is commenced on the second or third day. Union is usually complete in about four weeks.

#Separation of Epiphysis.#--The upper epiphysis of the humerus includes the head, both tuberosities, and the upper fourth of the inter-tubercular groove. On its under aspect is a cup-like depression into which the central pyramidal-shaped portion of the diaphysis fits. This epiphysis unites about the twenty-first year.

Traumatic separation is met with chiefly between the fifth and fifteenth years, and is most common in boys. It usually results from forcible traction of the arm upwards and away from the side, as in lifting a child by the upper arm, or from direct violence, but may be caused by a fall on the lateral side of the elbow.

The epiphysis, especially in young children, may be separated without being displaced, or the displacement may be incomplete.

When the epiphysis is completely separated from the shaft, the clinical features closely resemble those of fracture of the surgical neck, and the diagnosis is made by a consideration of the age of the patient, and the muffled character of the crepitus, when it can be elicited. The upper end of the diaphysis forms a projecting ridge which may be felt below and in front of the acromion. The diagnosis can usually be established by the use of the X-rays (Fig. 30). Dislocation is rare at the age when separation of the epiphysis occurs.

Reduction is often difficult on account of the periosteum and other soft tissues getting between the fragments, and on account of the small size of the upper fragment. Union almost invariably results, but the growth of the limb may be interfered with and its shape altered, especially when the injury occurs at an early age and its nature is overlooked.

Treatment.--This injury is treated on the same general lines as fracture of the surgical neck. General anaesthesia is almost always necessary to secure satisfactory reduction, and retention is most easily secured if the patient is confined to bed with the upper arm fixed in the fully abducted position. Operative treatment is called for in exceptional cases.

#Fractures of the Head, Anatomical Neck, and Tuberosities of Humerus.#--These fractures are met with as accompaniments of dislocation of the shoulder, and as results of gun-shot injuries, blows, or falls.

In sub-coracoid dislocation the head of the humerus may be indented by coming in contact with the anterior edge of the glenoid cavity (F. M. Caird).

The anatomical neck may be fractured in an old person by a direct blow on the shoulder. In a few cases the fracture is entirely intra-capsular, the head of the bone remaining loose in the cavity of the joint. As a rule, however, the fracture passes laterally and implicates the tuberosities. In some cases there is impaction, and in others comminution of the fragments. The use of the X-rays has shown that in many cases in which prolonged stiffness has followed a severe blow of the shoulder, there has been a fracture of the anatomical neck.

The tuberosities may be implicated in other fractures in this region and in dislocation of the shoulder; and either of them may be separated by muscular contraction or by direct violence.

Clinically all these injuries are difficult to diagnose with accuracy, and, without the use of the X-rays, it is impossible in many cases to go further than to say that a fracture exists above the level of the surgical neck. Fracture of the anatomical neck is attended with little deformity beyond slight flattening of the shoulder and sometimes slight shortening of the upper arm.

When the great tuberosity is torn off, considerable antero-posterior broadening of the shoulder may be recognised by grasping the region of the tuberosities between the fingers and thumb. Crepitus can be elicited on rotating the humerus. At the same time it will be recognised that the tuberosity does not move with the shaft. Firm union, with considerable formation of callus and some broadening of the shoulder, usually results, but the usefulness of the joint is not necessarily impaired. There may, however, be prolonged stiffness and impaired movement from adhesion; or pain and crackling in the joint may result from arthritic changes like those of arthritis deformans.

Treatment.--These fractures are treated on the same lines as fracture of the surgical neck of the humerus.

The combination of fracture of the upper end of the humerus with dislocation of the shoulder has already been referred to.

FRACTURE OF THE SHAFT OF THE HUMERUS

Fractures occurring in the shaft of the humerus between the surgical neck and the base of the condyles may, for convenience of description, be divided into those above, and those below, the level of the deltoid insertion--the majority being in the latter situation.

Direct violence is the most common cause of these fractures, but they may occur from a fall on the elbow or hand; and a considerable number of cases are on record where the bone has been broken by muscular action--as in throwing a cricket-ball. Twisting forms of violence may produce spiral fractures.

The fracture is usually transverse in children and in cases in which it is due to muscular action. In adults, when due to external violence, it is usually oblique, the fragments overriding one another and causing shortening of the limb. The displacement depends largely on the direction of the force and the line of fracture, but to a certain extent also on the action of muscles attached to the fragments. Thus, in fractures above the insertion of the deltoid the upper fragment is usually dragged towards the middle line by the muscles inserted into the inter-tubercular groove, while the lower is tilted laterally by the deltoid. When the break is below the deltoid insertion the displacement of the fragments is reversed. The signs of fracture--undue mobility, deformity, shortening, and crepitus--are at once evident, and the patient himself usually recognises that the bone is broken.

The nerve-trunks in the arm--the median, ulnar, and radial (musculo-spiral)--are apt to be damaged in these injuries; in fractures of the lower part of the shaft the radial nerve is specially liable to be implicated. This may occur at the time of the injury, the nerve being contused by the force causing the fracture, or pressed upon by one or other of the fragments, or its fibres may be partly or completely torn across. When there is evidence of nerve injury, the practitioner should draw the attention of the patient to it then and there, and so guard himself against actions for malpraxis should paralysis of the muscles ensue. Later, the nerve may become involved in callus, or be damaged by the pressure of ill-fitting splints. Weakness or paralysis of the extensors of the wrist and hand results, giving rise to the characteristic "wrist-drop." The actions of the muscles should always be tested before applying splints, and each time the apparatus is removed or readjusted, to assure that no undue pressure is being exerted on the nerves.

Union takes place in from four to six weeks in adults, and in from three to four weeks in children. Delayed union, or want of union and the formation of a false joint, is more common in fractures of the middle of the shaft of the humerus than in any other long bone--a point to be borne in mind in treatment. Arrest of growth in the bone from injury to the nutrient artery is also said to have occurred.

Treatment.--To restore the alignment of the bone, extension is made on the lower fragment and the ends are manipulated into position. This may necessitate the use of a general anaesthetic, and care must be taken that no soft tissue intervenes between the fragments, as is evidenced radiographically by the persistence of a clear space between the ends even when they appear to be in apposition.

In transverse fractures the position may be maintained by a simple ferrule of poroplastic or Gooch-splinting. The elbow is flexed at a right angle, and the forearm supported in a sling midway between pronation and supination. For a few days the limb may be bound to the chest by a broad roller bandage.

The splints are removed daily to admit of massage and movement being carried out, and while the splints are off, the patient is allowed to exercise the fingers and wrist. If at the end of four or five weeks, osseous union has not occurred, the reparative process may be hastened by inducing venous congestion by Bier's method.

In oblique and spiral fractures it is often necessary to control the shoulder and elbow-joints to prevent re-displacement. This can be done by means of a plaster of Paris case enclosing the upper part of the thorax, together with the upper arm, abducted, and the elbow, at right angles.

It is sometimes necessary to apply continuous extension to the lower fragment to prevent overriding. For this purpose a Thomas' arm splint is employed, the extension tapes being attached to its lower end, but care must be taken that the traction is not sufficient to separate the fragments and leave a gap between them. The elbow should not be retained in the extended position for more than three weeks.

In rare cases it is necessary to have recourse to operative treatment.

When there is evidence that the radial nerve has been injured, and no sign of improvement appears within three or four days of the accident, operative interference is indicated. An incision is made on the lateral side of the arm, and the nerve exposed and freed from pressure, or stitched, as may be necessary; the opportunity should also be taken of dealing with the fracture. The limb is put up in a "cock-up" splint, with the hand in the attitude of marked dorsiflexion (Fig. 31).

Satisfactory results have been obtained without the use of splints, by relying upon massage to overcome the spasm of muscles, and allowing the weight of the arm to act as an extending force (J. W. Dowden and A. Pirie Watson).

In cases of un-united fracture, a vertical or semilunar incision is made over the lateral aspect of the bone, and the muscles separated from one another till the fracture is exposed, care being taken to avoid injuring the radial nerve. The fibrous tissue is removed from the ends of the bone, and the rawed surfaces fixed in apposition; the wound is then closed, and appropriate retentive apparatus applied. As soon as the wound has healed, massage and movement are employed.

IV. INJURIES IN THE REGION OF THE ELBOW AND FOREARM

Surgical Anatomy--Examination of injured elbow--FRACTURE OF LOWER END OF HUMERUS: Supra-condylar; Inter-condylar; Separation of epiphysis; Fracture of either condyle alone; Fracture of either epicondyle alone--FRACTURE OF UPPER END OF ULNA: Olecranon; Coronoid--FRACTURE OF UPPER END OF RADIUS: Head; Neck; Separation of epiphysis--DISLOCATION OF ELBOW: Both bones; Ulna alone; Radius alone--FRACTURE OF FOREARM: Both bones; Radius alone; Ulna alone.

The injuries met with in the region of the elbow-joint include the various fractures of the lower end of the humerus, and upper ends of the bones of the forearm, including the olecranon; and dislocations and sprains of the elbow-joint. The differential diagnosis is often exceedingly difficult on account of the swelling and tension which rapidly supervene on most of these injuries, the pain caused by manipulating the parts, and the difficulty of determining whether movement is taking place at the joint or near it.

#Surgical Anatomy.#--The medial epicondyle of the humerus is more readily felt through the skin than the lateral. The two epicondyles are practically on the same level, and a line joining them behind passes just above the tip of the olecranon when the arm is fully extended. On flexing the joint, the tip of the olecranon gradually passes to the distal side of this line, and when the joint is fully flexed the tip of the olecranon is found to have passed through half a circle. The head of the radius can be felt to rotate in the dimple on the back of the elbow just below the lateral epicondyle. The coronoid process may be detected on making deep pressure in the hollow in front of the joint. As the line of the radio-humeral joint is horizontal, while that of the ulno-humeral joint slopes obliquely downwards, the arm forms with the fully extended and supinated forearm an obtuse angle, opening laterally--the "carrying angle." This angle is usually more marked in women, in harmony with the greater width of the female pelvis. The ulnar nerve lies in the hollow between the olecranon and the medial condyle, and the median nerve passes over the front of the joint, with the brachial artery and biceps tendon to its lateral side. The radial nerve divides into its superficial and deep (posterior interosseous) branches at the level of the lateral condyle.

In examining an injured elbow, the thumb and middle finger are placed respectively on the two epicondyles, while the index locates the olecranon and traces its movements on flexion and extension of the joint. The movements of the head of the radius are best detected by pressing the thumb of one hand into the depression below the lateral epicondyle, while movements of pronation and supination are carried out by the other hand. The uninjured limb should always be examined for purposes of comparison.

In injuries about the elbow much aid in diagnosis is usually obtained by the use of the X-rays; but in young children it is sometimes impossible, even with excellent pictures, to make an accurate diagnosis by means of radiograms alone. In cases of suspected fracture, a radiogram should be taken with the back of the limb resting on the plate, the forearm being extended and supinated. If a dislocation is suspected and a lateral view is desired, the arm should be placed on its medial side. In obscure cases it is useful to take radiograms of the healthy limb in the same position.

FRACTURES OF THE LOWER END OF THE HUMERUS

The following fractures occur at the lower end of the humerus: (1) supra-condylar fracture; (2) inter-condylar fracture; (3) separation of epiphyses; (4) fracture of either condyle alone; and (5) fracture of either epicondyle alone.

All these injuries are common in children, and result from a direct fall or blow upon the elbow, or from a fall on the outstretched hand, especially when at the same time the joints are forcibly moved beyond their physiological limits, more particularly in the direction of pronation or abduction. While it is generally easy to diagnose the existence of a fracture, it is often exceedingly difficult to determine its exact nature. Although the ulnar and median nerves are liable to be injured in almost any of these fractures, they suffer much less frequently than might be expected.

Ankylosis, or, more frequently, locking of the joint, is a common sequel to many of these injuries. This is explained by the difficulty of effecting complete reduction, and by the wide separation of periosteum which often occurs, favouring the production of an excessive amount of new bone, particularly in young subjects.

The #supra-condylar# fracture usually results from a fall on the outstretched hand with the forearm partly flexed, from a direct blow, or from a twisting form of violence. The line of fracture is generally transverse, or but slightly oblique from behind downwards and forwards, so that the lower fragment is forced backward together with the bones of the forearm, simulating backward dislocation of the elbow; the lower end of the upper fragment lies in front (Fig. 33).

Clinical Features.--The elbow is flexed at an angle of 120 deg. or 130 deg., and the forearm, held semi-pronated, is supported by the other hand. Around the seat of fracture great swelling rapidly ensues. The olecranon projects behind, but the mutual relations of the bony points of the elbow are unaltered. The lower end of the upper fragment may be felt in front above the level of the joint, as a rough and sharp projection, and this sometimes pierces the soft parts and renders the fracture compound. Movement at the joint is possible, but unnatural mobility may be detected above the level of the joint. Crepitus and localised tenderness may be elicited. The displacement is readily reduced by manipulation, but usually returns when the support is withdrawn. The arm is shortened to the extent of about half an inch.

In rare cases the obliquity of the fracture is downward and backward, and the lower fragment is displaced forward.

The #inter-condylar# fracture is a combination of the supra-condylar with a vertical split running through the articular surface, and so implicating the joint. The condyles are thus separated from one another, as well as from the shaft, by a T- or Y-shaped cleft. As such fractures usually result from severe forms of direct violence, they are often comminuted and compound. In addition to the signs of supra-condylar fracture, the joint is filled with blood. The condyles may be felt to move upon one another, and coarse crepitus, which has been likened to the feeling of a bag of beans, may be elicited if the fragments are comminuted.

#Separation of the lower epiphysis# of the humerus is met with in children of three or four years of age, but it may occur up to the thirteenth or fourteenth year. The more common lesion, however, is a combination of separated epiphysis with fracture, and this lesion is produced by the same forms of violence as cause supra-condylar fracture. If the periosteum is not torn, there is little or no displacement, but as a rule the clinical features closely resemble those of transverse fracture above the condyles, or of dislocation of the elbow. In separation of the epiphysis there is a peculiar deformity of the posterior aspect of the joint, consisting of two projections--one the olecranon, and the other the prominent capitellum with a scale of cartilage which it carries with it from the lateral condyle (R. W. Smith and E. H. Bennett). The end of the diaphysis may be palpated through the skin in front. Muffled crepitus can usually be elicited, and there is pain on pressing the segments against one another. Sometimes the separation is compound, the diaphysis protruding through the skin.

Union takes place more rapidly than in fracture, but, owing to the excessive formation of callus from the torn periosteum in front of the joint, full flexion is often interfered with. If the displaced epiphysis is imperfectly reduced, serious interference with the movements of the elbow is liable to ensue, and may call for operative treatment.

#Fracture of either Condyle alone.#--The lateral condyle or trochlea is more frequently separated from the rest of the bone than is the medial or capitellum. In either, the size of the fragment varies, but the line of fracture is partly extra-capsular and partly intra-capsular, so that the joint is always involved. Pain, crepitus, and the other signs of fracture are present. As the ligaments of the joint are not as a rule torn, there is little or no immediate displacement of the fragment. Secondary displacement is liable to occur, however, during the process of union, producing alterations in the "carrying angle" of the limb--cubitus varus or cubitus valgus.

#Fracture of Epicondyles.#--Fracture of the lateral epicondyle alone is so rare that it need only be mentioned.

The medial epicondyle may be chipped off by a fall on the edge of a table or kerbstone, or it may be forcibly avulsed by traction through the ulnar collateral (internal lateral) ligament, as an accompaniment of dislocation. It is usually displaced downwards and forwards by the flexor muscles attached to it, and may thus come to exert pressure on the ulnar nerve. The fragment may be grasped and made to move on the shaft, producing crepitus. Fibrous union is the usual result.

Up to the age of seventeen or eighteen the epiphysis of the epicondyle may be separated.

#Treatment of Fractures in Region of Elbow.#--The administration of a general anaesthetic is a valuable aid to accurate reduction and fixation of fractures in this region. Much discussion has taken place as to the best position in which to treat these fractures. In our experience the best approximation of the fragments, as shown by the X-rays, is obtained when the limb is fixed in the position of full flexion with supination. American surgeons favour the position of flexion at a right angle. In the region of the elbow there is a risk of promoting too much callus formation by early and vigorous massage, with the result that the movements of the joint are restricted by locking of the bony projections. This is probably due to bone cells being forced into the surrounding tissues, where they multiply and form new bone on an exaggerated scale.

The supra-condylar fracture is reduced by first extending the elbow to free the lower fragment from the triceps, and then, while making traction through the forearm, manipulating the fragments into position, and finally flexing the elbow to an acute angle and supinating the forearm. In this way the triceps is put upon the stretch and forms a natural posterior splint. A layer of wadding is placed in the bend of the elbow to separate the apposed skin surfaces, the arm placed in a sling so arranged as to support the elbow, and fixed to the side by a body bandage. This position is maintained for three weeks, with daily massage and movement. The last movement to be attempted is that of complete extension. Operative treatment is rarely called for.

Separation of the epiphysis and fracture of the medial epicondyle are treated on the same lines as supra-condylar fracture.

T- or Y-shaped fractures and fractures of the condyles, inasmuch as they implicate the articular surfaces, present greater difficulties in treatment, but they are treated on the same lines as the supra-condylar. In young subjects whose occupation entails free movement of the elbow-joint, it is sometimes advisable to expose the fracture by operation and secure the fragments in position. The details of the operation vary in different cases, and depend upon the line of obliquity of the fracture, and the disposition of the individual fragments, points which may usually be determined by the use of the X-rays. In performing the operation, care must be taken to disturb the periosteum as little as possible, otherwise there may follow excessive formation of new bone.

Operative interference is sometimes necessary for ankylosis or locking of the joint after the fracture is united, or to relieve the ulnar nerve when it is involved in callus. Volkmann's ischaemic contracture is liable to occur after fractures in the region of the elbow from impairment of the blood supply as a result of tight bandaging.

FRACTURE OF THE UPPER END OF THE ULNA

#Fracture of the olecranon# is a comparatively common injury in adults. It usually follows a fall on the flexed elbow, and results from the direct impact, supplemented by the traction of the triceps muscle. In a few cases it has been produced by muscular action alone. The line of fracture may pass through the tip of the process, or through its middle, less frequently through the base. It may be transverse, oblique, T- or V-shaped, but is rarely comminuted or compound.

Clinical Features.--As the fracture almost invariably implicates the articular surface, there is considerable swelling from effusion of blood into the joint. The power of extending the forearm is impaired, and other symptoms of fracture are present. The amount of displacement depends upon the level of the fracture, and the extent to which the aponeurotic expansion of the triceps is torn. As the fracture is usually near the tip, the displacement is comparatively slight, the prolongation of the fibres of insertion of the triceps on to the sides and posterior part of the process holding the small fragment in position; and the fracture may easily escape recognition. When the line of fracture is nearer the base, however, the contraction of the triceps tends to separate the fragments widely (Fig. 35), and a distinct gap, which is increased on flexing the elbow, may often be felt between them, and if the elbow is passively extended, the fragments may be brought into apposition, and crepitus elicited.

When there is little displacement, bony union may result, but in many cases the fragments are united only by fibrous tissue. The upper fragment sometimes forms attachments to the shaft of the humerus, and this leads to stretching of the fibrous band between the fragments and to marked wasting of the triceps.

Separation of the olecranon epiphysis is one of the rarest forms of epiphysial detachment (Poland). When the epiphysis is displaced upwards and unites in this position, it may interfere with complete extension of the elbow.

Treatment.--It would appear that too much stress has hitherto been laid on the necessity of bringing the fragments into perfect apposition, and too little attention paid to the importance of maintaining the functions of the triceps and the movements of the elbow-joint.

Massage and movements are carried out from the first, and the forearm is supported in a sling. Full flexion is the last movement to be attempted. In carrying out the movements, the tip of the olecranon is pressed down with the thumb, so that it is obliged to follow the movements of the ulna, and is prevented from adhering to the humerus.

It was formerly the practice to have the arm almost, but not quite, fully extended, and a Gooch splint, extending from the lower border of the axilla to the finger-tips, and cut to the shape of the extended limb, applied anteriorly and fixed in position by a bandage, the region of the elbow being covered by a convergent spica.

Operative Treatment.--Operative treatment may be had recourse to, particularly in cases in which there is wide separation of the fragments. The fracture is exposed, the joint cavity opened up and cleared of clots, and silver-wire sutures passed through the fragments without encroaching upon the articular cartilage. The limb is fixed with the elbow-joint in the position of almost complete extension. Movement may be commenced at the end of a week, the angle at which the joint is fixed being changed morning and evening. During the day the flexed position should be maintained and the arm carried in a sling; during the night the limb is fixed to a pillow in the extended position. The patient is allowed to use the joint cautiously within a fortnight.

Old-standing Fracture.--When union fails to take place, the interval between the fragments tends to increase by the contraction of the triceps gradually stretching the intermediate fibrous tissue, so that a wide gap comes to separate the fragments. It is quite common that the function of the arm is all that can be desired in spite of a gap between the fragments, but, if this is not the case, the fragments may be united by operation.

#Fracture of the coronoid process# is rare except as a complication of backward dislocation of the elbow. It may be produced by direct violence, as well as by muscular action. As the fracture is usually within a quarter of an inch of the tip, the fibres of insertion of the brachialis prevent displacement. The ordinary evidence of fracture is often absent, and the diagnosis is seldom completed without the aid of the X-rays. The treatment consists in flexing the elbow and supporting the forearm in a sling. In some cases associated with dislocation, however, the small fragment has been so far displaced as to become attached to the back of the humerus (Annandale).

FRACTURE OF THE UPPER END OF THE RADIUS

Intra-capsular fracture of the #head of the radius# may result from direct violence, from a fall on the pronated hand, or from forcible pronation or abduction--that is, deviation of the forearm to the radial side. It may accompany dislocation of the elbow or fracture of adjacent bones. The head may be completely separated, or may be split into two or more fragments. Up to the seventeenth year, the epiphysis, which is entirely intra-articular, may be separated.

The clinical features are localised pain, crepitus, interference with pronation and supination, while the elbow can be almost fully extended and flexed, and in some cases the fragment may be felt through the skin, although it usually continues to move with the shaft in pronation and supination.

Union generally takes place satisfactorily, but in some cases the fragments form new attachments resulting in impaired movement at the elbow, and necessitating operative interference.

Fracture of the #neck of the radius# between the capsule and the tubercle is rare.

#Avulsion of the tubercle# may occur from forcible contraction of the biceps, or, in children, from traction made on the forearm (A. L. Hall).

These injuries are treated with the elbow in the flexed position, and massage and movement are carried out as already described.

DISLOCATION OF THE ELBOW

Dislocations of the elbow-joint may involve one or both bones of the forearm, and may be complete or incomplete.

#Dislocation of both bones backward# is the most common of all dislocations of the elbow, and is the only dislocation that is frequently met with in children. It usually results from a fall on the outstretched hand, causing hyper-extension of the joint with abduction--that is, deviation towards the radial side; but it may follow a direct blow on the back of the humerus, a fall on the elbow, or a twist of the forearm.

Morbid Anatomy.--All the ligaments of the elbow, except the annular (orbicular), are torn or stretched. The radius and ulna pass backward, the coronoid process coming to rest opposite the olecranon fossa behind the humerus, and the head of the radius behind the lateral condyle. The condyles of the humerus bear their normal relations to one another. The olecranon and the triceps tendon form a marked prominence on the back of the elbow, the tip of the olecranon lying above and behind the condyles. The lower end of the humerus lies in the flexure of the joint with the biceps tendon tightly stretched over it. The coronoid process is often broken, or the tendon of the brachialis torn. The median and ulnar nerves may be stretched or torn. Not infrequently the bones of the forearm are displaced towards the medial side as well as backward.

Occasionally, as a sequel to the dislocation, processes of bone develop in relation to the insertion of the brachialis and interfere with the movements of the joint. These outgrowths are due to displacement of bone-forming elements, either at the time of the original injury or as a result of forcible efforts at reduction. According to D. M. Greig, they do not develop in the tendon of the brachialis, but under it, and are not of the nature of myositis ossificans. In from four to six weeks after reduction of the dislocation, the movements begin to be restricted, and a hard mass can be felt in the cubital fossa, which with the X-rays is seen to be a bony outgrowth springing from the quadrilateral space on the front of the elbow below the coronoid process (Fig. 37). This gradually increases in size and leads to fixation of the joint. In most cases the effects reach their maximum in about six months, and then reabsorption of the mass begins.

If the disability shows no sign of abatement within a year, or if the bony outgrowth is producing pressure effects on the median nerve, it should be removed by operation.

It is important not to mistake this condition for the effects of a fracture which has complicated the dislocation and been overlooked at the time of the accident.

Clinical features.--The elbow is held fixed at an angle of about 120 deg., pronated or midway between pronation and supination. Any attempt at movement causes great pain, and is followed by an elastic rebound to the abnormal position. The antero-posterior diameter of the joint is increased, and the forearm, as measured from the lateral epicondyle to the tip of the styloid process of the radius, is shortened to the extent of about an inch. If examined before swelling ensues, the outlines of the articular surfaces may be recognised in their abnormal positions, but swelling usually comes on rapidly, and, by obscuring the bony landmarks, renders the diagnosis difficult.

This injury has to be diagnosed from supra-condylar fracture with backward displacement of the lower fragment and from separation of the lower humeral epiphysis. A general anaesthetic is often necessary to enable an accurate diagnosis to be made. When the deformity is once reduced, there is no tendency to its reproduction unless the coronoid process is also fractured. In a considerable number of cases--according to E. H. Bennett, in the majority--this dislocation is incomplete, the coronoid process resting at the level of the trochlea, and the backward projection of the olecranon being scarcely appreciable. The head of the radius, however, is unduly prominent. In such cases the lesion is liable to be overlooked, and therefore to go untreated, leading to permanent stiffness at the elbow.

#Dislocation forward# is much less common than the backward variety. It is produced by severe force acting from behind on the flexed elbow, the ulna being driven forward, tearing the ligaments of the joint and the muscles attached to the condyles. The olecranon is frequently fractured at the same time (Fig. 39). When it remains intact, it may rest below the condyles (incomplete or first stage of dislocation), or may pass in front of them, especially if the triceps is ruptured (complete or second stage). The forearm is lengthened, the elbow slightly flexed, the posterior aspect of the joint flattened, and the condyles, in their abnormal relationship, can be palpated from behind.

#Medial and Lateral Dislocations.#--Dislocation towards the ulnar side is always incomplete, some portion of the articular surface of the bones of the forearm remaining in contact with the condyles.

The dislocation to the radial side is also incomplete as a rule, although cases have been recorded in which complete separation had taken place.

These forms of dislocation are rare, that towards the ulnar side being more frequently observed. Each form is often combined with other injuries in the vicinity.

The most common cause of these dislocations is a fall on the outstretched hand, the forearm at the moment being strongly pronated. Forced abduction favours the displacement to the ulnar side; adduction to the radial side. The limb is held flexed and pronated, and the facility with which the bony points can be palpated renders the diagnosis easy.

In a few cases diverging dislocations have been met with, the radius and ulna being separated from one another, the annular (orbicular) ligament being torn and no longer holding them together.

#Treatment of Dislocations of Elbow.#--The chief obstacle to reduction is the spasmodic contraction of the muscles passing over the joint, and, in the backward variety, the hitching of the coronoid process against the edge of the olecranon fossa. In recent cases, to effect reduction the patient is seated on a chair, while the surgeon grasps the humerus and wrist, and places his knee in the bend of the elbow. The limb is first fully extended, or even hyper-extended, to relax the triceps and free the coronoid process. Traction is then made in opposite directions upon the forearm and arm, the surgeon's knee meanwhile making pressure, in a backward direction, upon the lower end of the humerus. The joint is next slowly flexed, and the bones slip into position, often with a distinct snap. If the patient be anaesthetised, these manipulations must be adapted to the recumbent position.

When some days have elapsed before reduction is attempted, forcible manipulations are to be deprecated as they greatly increase the risk of ossification occurring in relation to the brachialis (D. M. Greig); and recourse should be had to open operation, and the tearing or bruising of the soft parts should be reduced to a minimum.

After reduction, the limb is flexed to rather less than a right angle and supported by a sling. Massage and movement are commenced at once.

Fracture of the coronoid process predisposes to recurrence of the dislocation; when this complication exists, therefore, the limb should be fixed at an acute angle, and movements of full extension postponed for a fortnight. Massage and limited movements, however, may be carried out from the first.

If there is a fracture of the olecranon, the treatment must be modified accordingly (p. 87).

Comminuted and compound injuries usually call for operative treatment, the fractured bones being wired after reduction of the dislocation, or the loose fragments removed.

The forward dislocation is reduced by fully flexing the elbow, and then pushing the bones of the forearm backward, while the humerus is pulled forward.

Old-standing Dislocations.--No attempt should be made to reduce by manipulation a dislocation of the elbow which has remained displaced for five or six weeks, especially when it has been complicated by a fracture. The joint surfaces become welded together by adhesions, and separated fragments often form attachments which lock the joint. Attempts to break these down are attended with considerable risk of re-fracturing the bone or of tearing the soft parts. In such cases it is best to expose the joint, and if reduction is not easily effected a sufficient amount of the lower end of the humerus should be removed to provide a movable joint.

#Dislocation of the ulna alone# is a rare injury, and is usually associated with fracture of one or other of its processes or of the inner condyle.

#Dislocation of the radius alone#, on the other hand, is comparatively common, especially as a concomitant of fracture of the upper third of the shaft of the ulna (Fig. 40).

The injury may result from a blow on the back of the upper end of the radius, a fall on the outstretched hand, or, in children, from forcible traction on the forearm while in the pronated position. The displaced head usually passes forward, and rests on the anterior edge of the capitellum, thus preventing complete flexion and supination of the limb.

The limb is held partly flexed and pronated. The displaced head of the radius can be felt to rotate with the shaft in its abnormal position, and the articular facet on the head of the radius may also be felt; there is a depression posteriorly below the lateral epicondyle where the head should be. The radial side of the forearm is slightly shortened. The superficial and deep (posterior interosseous) branches of the radial nerve are liable to be pressed upon or torn by the displaced head of the radius, especially if the ulna is fractured, leading to disturbances in the area of their distribution.

In a few cases the displacement of the head has been backwards or laterally.

Treatment.--To effect reduction, the forearm should be alternately flexed and extended, while traction is made upon it from the wrist, and the head of the radius is pressed backward with the thumb in the fold of the elbow. When reduction is prevented by the interposition of a portion of the torn ligaments between the bones, it is sometimes necessary to open the joint to ensure accurate adjustment. The joint is fixed in acute flexion to relax the biceps, to allow of union of the torn ligaments, and to prevent recurrence.

In old-standing cases, to obtain a useful joint, or to remove pressure from the branches of the radial nerve, resection of the head of the radius may be necessary.

#Sub-luxation of the head of the radius#, or "dislocation by elongation," is a comparatively common injury in children between the ages of two and six. It almost invariably results from the child being lifted or dragged by the hand or forearm. The traction and torsion thus put upon the radius causes the front part of its head to pass out of the annular ligament, the edge of which slips between the bones.

The person holding the child may feel a click at the moment of displacement. The child complains of pain in the region of the elbow: the arm at once becomes useless, and is held flexed, midway between pronation and supination. All movements are painful, but especially movements in the direction of supination. The deformity is slight, but the head of the radius may be unduly prominent in front. From the way in which the injury is produced the wrist also is often swollen, and in some cases the patient is brought to the surgeon on account of the condition of the wrist, and attention is not directed to the elbow.

Treatment.--Reduction frequently takes place spontaneously or during examination, the function of the arm being at once completely restored. In other cases it is necessary, under anaesthesia, to manipulate the head of the bone into position. This is usually easily done by flexing the elbow, making slight traction on the forearm, and alternately pronating and supinating it. After reduction, a few days' massage is all that is necessary, the joint in the intervals being kept at rest in a sling.

#Sprain# of the elbow is comparatively common as a result of a fall on the hand or a twist of the forearm. The point of maximum tenderness is usually over the radio-humeral joint, the radial collateral and annular ligaments being those most frequently damaged. Effusion takes place into the synovial cavity, and a soft, puffy swelling fills up the natural hollows about the joint. The bony points about the elbow retain their normal relationship to one another--a feature which aids in determining the diagnosis between a sprain and a dislocation or fracture. In children it is often difficult to distinguish between a sprain and the partial separation of an epiphysis. Sprains of the elbow are treated on the same lines as similar lesions elsewhere--by massage and movement.

The condition known as tennis elbow is characterised by severe pain over the attachment of one or other of the muscles about the elbow, particularly the insertion of the pronator teres during the act of pronation, and is due to stretching or tearing of the fibres of that muscle, and of the adjacent intermuscular septa. A similar injury--sculler's sprain--occurs in rowing-men from feathering the oar. The treatment consists in massage and movement, care being taken to avoid the movement which produced the sprain.

FRACTURE OF THE FOREARM

The shafts of the bones of the forearm may be broken separately, but it is much more common to find both broken together.

#Fracture of both bones# may result from a direct blow, from a fall on the hand, or from their being bent over a fixed object. The line of fracture is usually transverse, both bones giving way about the same level. The common situation is near the middle of the shafts. In children, greenstick fracture of both bones is a frequent result of a fall on the hand--this indeed being one of the commonest examples of greenstick fracture met with (Fig. 41).

The displacement varies widely, depending partly upon the force causing the fracture, partly on the level at which the bones break, and on the muscles which act on the respective fragments. It is common to find an angular displacement of both bones to the radial or to the ulnar side. In other cases the four broken ends impinge upon the interosseous space, and may become united to one another, preventing the movements of pronation and supination. There may be shortening from overriding of fragments.

When the radius is broken above the insertion of the pronator teres, its upper fragment may be supinated by the biceps and supinator muscles, while the lower fragment remains in the usual semi-prone position. If union takes place in this position, the power of complete supination is permanently lost.

The usual symptoms of fracture are present, and there is seldom any difficulty in diagnosis.

The prognosis must be guarded, especially with regard to the preservation of pronation and supination. These movements are interfered with if union takes place in a bad position with angular or rotatory deformity of one or both bones, or if callus is formed in excess and causes locking of the bones. In some cases the callus fuses the two bones across the interosseous space, and pronation and supination are rendered impossible.

Persistent angular deformity of the forearm is also liable to ensue, either from failure to correct the displacement primarily, or from subsequent bending due to ill-applied splints or slings. Want of union, or the formation of a false joint in one or both bones, is sometimes met with, particularly in children, and, like the corresponding fracture of the leg, is liable to prove intractable.

A considerable number of cases of gangrene of the hand after simple fracture of the forearm are on record. This is sometimes attributable to damage inflicted upon the blood vessels by the fractured bones, or to the force that caused the fracture, but is oftener due to a roller bandage applied underneath the splints strangulating the limb, to injudiciously applied pads, or to too tight bandaging over the splints. Volkmann's ischaemic contracture occasionally develops after fractures of the forearm.

In uncomplicated cases, union takes place in from three to four weeks.

Treatment.--To ensure accurate reduction and coaptation, a general anaesthetic is usually necessary. In the greenstick variety the bones must be straightened, the fracture being rendered complete, if necessary, for this purpose.

To retain the bones in position, anterior and posterior splints are then applied. These are made to overlap the forearm by about half an inch on each side, to avoid compressing the forearm from side to side, and so making the fractured ends encroach upon the interosseous space. The dorsal splint is usually made to extend from the olecranon to the knuckles, and the palmar one from the bend of the elbow to the flexure in the middle of the palm, a piece being cut out to avoid pressure on the ball of the thumb (Fig. 42). The splints are applied with the elbow flexed to a right angle, and, except when the radius is broken above the level of the insertion of the pronator teres, with the forearm midway between pronation and supination. The limb is placed in a sling, so adjusted that it supports equally the hand and elbow in order to avoid angular deformity. The use of special interosseous pads is to be avoided.

When the fracture of the radius is above the insertion of the pronator teres, the forearm should be placed in the position of complete supination, with the elbow flexed to an acute angle, and retained in this position by a moulded posterior splint, and the arm fixed to the side by a body bandage. Great care is necessary in the adjustment of the apparatus to prevent pronation.

Massage and movement should be carried out from the first. It is usually necessary to continue wearing the splints for about three weeks.

In cases of mal-union, especially when the bones are ankylosed to one another across the interosseous space, operation may be necessary, but it is neither easy in its performance nor always satisfactory in its results. The seat of fracture should be exposed by one or more incisions so placed as to enable the muscles to be separated and to give access to the callus. When the limb is straight, it is only necessary to gouge away the exuberant callus that interferes with rotatory movements; but when there is an angular deformity the bones must, in addition, be divided and re-set, and, if necessary, mechanically fixed in good position. In comparatively recent cases it is sometimes possible, without operation, to re-fracture the bones and to set them anew.

Un-united fracture of both bones of the forearm is not uncommon and is treated on the usual lines; the gap between the fragments of the radius is bridged by a portion of the fibula, that should be long enough to overlap by at least an inch at either end; it is rarely necessary to bridge the gap in the ulna, unless it alone is the seat of non-union.

#Fracture of the shaft of the radius alone# may be due to a direct blow; to indirect violence, such as a fall on the hand; or to forcible pronation against resistance, as in wringing clothes. It is rare in comparison with fracture of both bones. When broken above the insertion of the pronator teres, the upper fragment is flexed and supinated by the biceps and supinator, while the lower fragment remains semi-prone, and is drawn towards the ulna by the pronator quadratus.

When the fracture is below the pronator teres, the displacement depends upon the direction of the force and the obliquity of the fracture. In fractures of the lower third of the shaft, the hand may be flexed toward the radial side, and the styloid lies at a higher level, as in a Colles' fracture. From the frequency with which this fracture occurs while cranking a motor-car, it is conveniently described as Chauffeur's fracture; we have observed in doctors, who have sustained this fracture in their own persons, that they were under the impression that they had sustained a trivial sprain of the wrist.

In addition to the ordinary signs of fracture, there is partial or complete loss of pronation and supination. The head of the radius as a rule does not move with the lower part of the shaft, but may do so if the fracture is incomplete or impacted.

#Fracture of the shaft of the ulna alone# is also comparatively rare. It is almost always due to a direct blow sustained while protecting the head from a stroke, or to a fall on the ulnar edge of the forearm, as in going up a stair.

The upper third is most frequently broken, and this injury is often associated with dislocation of the head of the radius (Fig. 40), or some other injury implicating the elbow-joint. On account of the superficial position of the bone, this fracture is frequently compound.

The displacement depends on the direction of the force, the fragments being usually driven towards the interosseous space. There is seldom marked deformity unless the head of the radius is dislocated at the same time. The diagnosis is, as a rule, easy.

The treatment is the same as for fracture of both bones, but the splints may be discarded at the end of a fortnight.

For some unexplained reason, a fracture of the upper third of the shaft of the ulna frequently fails to unite.