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 pract.i.tioner 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 a.s.sure 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 s.p.a.ce 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 p.r.o.nation and supination. For a few days the limb may be bound to the chest by a broad roller bandage.
[Ill.u.s.tration: FIG. 31.--"c.o.c.k-up" Splint, for maintaining Dorsiflexion at Wrist.]
The splints are removed daily to admit of ma.s.sage 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.
[Ill.u.s.tration: FIG. 32.--Gooch Splints for Fracture of Shaft of Humerus; and Rectangular Splint to secure Elbow.]
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 st.i.tched, as may be necessary; the opportunity should also be taken of dealing with the fracture. The limb is put up in a "c.o.c.k-up" splint, with the hand in the att.i.tude of marked dorsiflexion (Fig. 31).
Satisfactory results have been obtained without the use of splints, by relying upon ma.s.sage 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, ma.s.sage and movement are employed.
CHAPTER 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 pa.s.ses just above the tip of the olecranon when the arm is fully extended. On flexing the joint, the tip of the olecranon gradually pa.s.ses to the distal side of this line, and when the joint is fully flexed the tip of the olecranon is found to have pa.s.sed 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 pa.s.ses 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 p.r.o.nation 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 p.r.o.nation 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).
[Ill.u.s.tration: FIG. 33.--Radiogram of Supra-condylar Fracture of Humerus, in a child aet. 7.]
_Clinical Features._--The elbow is flexed at an angle of 120 or 130, and the forearm, held semi-p.r.o.nated, 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 coa.r.s.e crepitus, which has been likened to the feeling of a bag of beans, may be elicited if the fragments are comminuted.
[Ill.u.s.tration: FIG. 34.--Radiogram of T-shaped Fracture of Lower End of Humerus.]
#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. m.u.f.fled 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 ma.s.sage, 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 ma.s.sage 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.