(Sir Robert Jones" case. Radiogram by Dr. D. Morgan.)]
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 a.s.sociated 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 p.r.o.nated position. The displaced head usually pa.s.ses _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 p.r.o.nated. 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.
[Ill.u.s.tration: FIG. 40.--Radiogram of Forward Dislocation of Head of Radius, with Fracture of Shaft of Ulna.]
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 pa.s.s 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 p.r.o.nation 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 p.r.o.nating and supinating it. After reduction, a few days"
ma.s.sage 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 ma.s.sage 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 p.r.o.nator teres during the act of p.r.o.nation, 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 ma.s.sage 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).
[Ill.u.s.tration: FIG. 41.--Greenstick Fracture of both Bones of the Forearm, in a boy.]
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 s.p.a.ce, and may become united to one another, preventing the movements of p.r.o.nation and supination. There may be shortening from overriding of fragments.
When the radius is broken above the insertion of the p.r.o.nator teres, its upper fragment may be supinated by the biceps and supinator muscles, while the lower fragment remains in the usual semi-p.r.o.ne 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 p.r.o.nation 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 s.p.a.ce, and p.r.o.nation 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 s.p.a.ce.
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 p.r.o.nator teres, with the forearm midway between p.r.o.nation 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.
[Ill.u.s.tration: FIG. 42.--Gooch Splints for Fracture of both Bones of Forearm. (These are applied with the wooden side towards the skin.)]
When the fracture of the radius is above the insertion of the p.r.o.nator 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 p.r.o.nation.
Ma.s.sage 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 s.p.a.ce, 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 p.r.o.nation against resistance, as in wringing clothes. It is rare in comparison with fracture of both bones. When broken above the insertion of the p.r.o.nator teres, the upper fragment is flexed and supinated by the biceps and supinator, while the lower fragment remains semi-p.r.o.ne, and is drawn towards the ulna by the p.r.o.nator quadratus.
When the fracture is below the p.r.o.nator 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 p.r.o.nation 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 a.s.sociated 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 s.p.a.ce. 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.
CHAPTER V
INJURIES IN THE REGION OF THE WRIST AND HAND