CHAPTER 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.