The deformities of the fingers and toes

by William Anderson

CONTRACTIONS OF PARALYTIC AND SPASTIC ORIGIN FOLLOWING LOCAL INJURY.

A complete account of the various conditions falling under this denomination would require an entire course of lectures, and it is hence necessary to confine our attention to those forms which belong to the surgeon rather than to the physician.

Spastic conditions following local injury are very rare. An example was brought before the Medical Society by Dr. Beevor[6] in April 1888, in which a contusion of the right hand in a boy of fifteen was followed five days later by permanent contraction of the hand with total anæsthesia as far as the shoulder and loss of the muscular sense, the movements of the arm and forearm remaining unimpaired. In the discussion a similar case was referred to by Dr. Hadden.

All the nerves which govern the muscles acting upon the fingers are liable to injury—the median and ulnar more particularly by wounds, usually in the wrist, and the musculo-spiral by pressure of a crutch.

An injury involving solution of continuity of the Ulnar nerve is a very grave accident, unless it can be treated surgically without any long delay. The symptoms are such as might be inferred from a knowledge of the distribution of the branches. It will be remembered that the nerve supplies the flexor carpi ulnaris and ulnar half of the flexor profundus digitorum in the forearm, the whole of the muscles of the hand, except the abductor, opponens, and outer head of the flexor brevis pollicis, and the two inner lumbricales, and it gives sensation to the skin over the inner side of the wrist and hand, to the palmar and dorsal surfaces of the little and ulnar half of the ring finger, and sometimes also to the radial half of the ring finger and ulnar half of the middle finger. The effects of the nerve lesion will, of course, vary with the position of the injury. If the trunk be divided just above the wrist, the branches to the two forearm muscles and the cutaneous branch to the back of the hand and fingers will be spared; but the palmar cutaneous filament will probably be implicated by the wound. The paralysis of the interossei produces an inability to flex the first phalanges and extend the second and third, while the unbalanced action of the extensor, and superficial and deep flexors, causes the position of super-extension of the metacarpo-phalangeal joint with flexion of the inter-phalangeal joints, which constitutes the main en griffe of French pathologists ([Fig. 9]). The clawing is chiefly marked in the ring and little digits, especially the latter, but is lessened in the index and middle fingers by the continued integrity of the first and second lumbricales. There is, in addition, great loss of power in flexion and adduction of the thumb, and complete loss of sensation over the front and distal part of the back of the little finger and the corresponding portion of the ulnar side of the ring finger. At a later stage nutritive changes appear in the paralysed structures, and the deformity becomes complicated by the atrophy of the skin and subcutaneous fat, the hollowing of the interosseous spaces and the wasting of the thenar and hypothenar eminences. If the nerve be injured at the elbow, the paralysis of the two forearm muscles, and the loss of sensation over the ulnar side of the back of the hand would add to the symptoms, but would not sensibly affect the deformity.

Fig. 9.

Deformity in case of wound of ulnar nerve above wrist.

The treatment is to seek for the divided ends of the nerve, and to unite them if possible. Should the interspace be too great to allow direct suture, an attempt might be made to restore continuity by cutting a long flap from the proximal extremity of the nerve and bringing it down to the distal end; or by the transplantation of a portion of nerve from an amputated limb, or from one of the lower animals. Where the wound lies immediately above the wrist, it is well to remember that the ulnar nerve and vessels are covered by a fibrous band, which passes from the radial side of the flexor carpi ulnaris tendon in this situation to blend with the anterior annular ligament. It should also be recollected that the deep branch of the nerve, which is occasionally implicated in penetrating wounds over the hypothenar eminence, runs around the ulnar side of the tip of the unciform process, and may there be exposed without much difficulty.[7] After operation the hand should be placed in a position of adduction and flexion, and the wound dressed antiseptically. Should this measure fail, the apparatus devised by Duchenne may be applied to replace the action of the paralysed muscles.

Musculo-spiral paralysis may be induced by ordinary wounds or contusions, by fractures of the humerus, or by long-continued compression of the nerve against the bone, either by the handle of a crutch, or while the patient is sleeping with his head resting upon an arm which is supported by the back of a chair. The consequences are paralysis of the elbow extensors, the supinator longus, the supinator brevis, and the whole of the extensors of the wrist, thumb, and fingers; and loss of sensation over the cutaneous areas supplied by the nerve in the arm, forearm, and hand. For the patient the most striking symptoms are the flexion of the wrist and fingers, the loss of power to abduct the thumb, and especially the enfeeblement of grasp due to the inability to fix the wrist during the action of the finger flexors. If the wrist be held firmly by the other hand, or by another person, in the position of extension, the power of grip becomes restored. A similar condition is present in lead poisoning; but here the loss of power is confined to the extensor muscles, and the supinator longus remains unaffected. The possibility of a crutch paralysis should lead the surgeon to warn every patient who is compelled to use the implement, in order that the paralysis may be prevented, or, should it occur, that it may be perceived and arrested in its earliest stages. When the condition has become established, an attempt should be made to restore function by massage and electricity, and if these fail, the nerve should be exposed at the seat of injury, and its continuity restored by the excision of the atrophic portion and union of the two free extremities.

In paralysis of the Median nerve by a wound above the wrist, the most distressing symptoms are referable to the trophic lesions in the integuments of the thumb, index, middle, and ring fingers (radial side) on their palmar surface and the distal half of their dorsal aspect. There is, in addition, a partial loss of power of flexion and abduction of the thumb, with wasting of the thenar eminence and some interference with the delicacy of the movements of the index and middle fingers, owing to the paralysis of the first and second lumbricales. If the nerve be divided above the elbow, the pronators and all the flexors of the wrist, thumb, and fingers, except those supplied by the ulnar nerve (flexor carpi ulnaris, and ulnar half of the flexor digitorum profundus), are paralysed, and consequently the hand is, for all practical purposes, quite useless. The rules for treatment are similar in principle to those laid down for injuries of the musculo-spiral and ulnar nerves.

Spastic Paralyses, in connection with central disease, need not be discussed; but the surgeon is sometimes consulted for conditions of persistent spasm which apparently depend upon excessive use of certain muscles. Erichsen refers to, and figures, a case of flexion with pronation attributed to cutting with heavy shears. He notes that when the wrist was extended the fingers became flexed, and when the wrist was extended the fingers became bent in. It is not stated whether the permanency of the contraction was tested by the use of an anæsthetic, but the patient, as well as another in whom the extensors were affected in like manner, became cured by means of friction and galvanism, with the use of a straight splint. A case of spastic contraction of the right little finger of thirty-five years’ duration was recently in the Mile End Infirmary. The flexion of the finger is associated with slight adduction of the hand, but the parts can be straightened completely by passive force. The condition is attributed to a wound near the elbow. There is no lesion of sensation.

The group of affections known as Writer’s cramp usually fall within the province of the physician, and will only be briefly referred to. They are of uncertain pathology, vary considerably in their manifestations, and, although most common in persons much engaged in writing, are by no means confined to these. The symptoms may assume three different types—spastic, paralytic, and tremulous—affecting the muscles of the hands and forearm, and these may be combined in various ways. The prognosis is unfavourable; but the treatment found most hopeful is to relieve the affected muscles from the strain to which they have been accustomed, and strengthen them by massage and galvanism. Interference by surgical operation has been unsuccessful, except in one case, in which Stromeyer divided the flexor longus pollicis tendon.