The deformities of the fingers and toes

by William Anderson

CONTRACTIONS ARISING FROM INTERRUPTED EVOLUTION OF THE FLEXORS OF THE FINGERS, WITHOUT PARALYTIC OR SPASTIC COMPLICATIONS.

This condition necessarily belongs to the pre-adult stage of development. It is characterised by persistent flexion of one or more digits, without any articular abnormality, and unassociated with spasm or paralysis, but the contraction is of a different kind from that found in hammer finger and hammer toe. The degree of flexion varies with the position of the hand, and when the wrist is strongly bent forwards the fingers may be extended, perhaps completely, but extension of the wrist is accompanied by a return of the contraction, the degree of which increases progressively as the wrist extension is carried nearer to its limit. The power of grasp is little impaired. Any attempt to overcome the flexion by violence is met by powerful resistance, and great pain is induced. If the patient be anæsthetised, the contraction remains unaltered, but the resistance is felt to be of a peculiar elastic character, and yields to a slight extent during the application of passive force. The defect leads to great interference with the functions of the hand. The pain caused by anything that tends to stretch the shortened muscles induces a voluntary exaggeration of the flexion, and after a time the control over the extensors is apt to become impaired. The causes are often obscure, but some examples have been traced to traumatic injuries of the flexor side of the forearm in infancy or childhood. In any case the essential factor appears to be a trophic lesion of local or central origin, which retards or arrests the due growth of a muscle or a portion of a muscle without causing its atrophy or paralysis. The following cases will serve to illustrate the phenomena so far as they have come under my own observation:

Case 1.—M. O., a domestic servant aged seventeen, was admitted into St. Thomas’s Hospital in September 1889. On examination the third, fourth, and fifth fingers of the right hand were found to be flexed at the metacarpo-phalangeal and inter-phalangeal joints—the two latter strongly, the former slightly. When the wrist was fully extended the contraction became more marked, and the distal phalanges of the ring and little fingers touched the palm, but when the wrist was fully flexed the fingers could be voluntarily brought into a state of complete extension. The power of grasp was good, although somewhat less than in the left arm; the bones were normal in form and size; and the joints were quite free in their movements when the flexors were relaxed by position. The forearm muscles appeared to be of normal size. A small scar was seen about two inches below the elbow, over the inner side of the front of the arm, the result of a fall thirteen years before. The patient was strong and healthy in appearance, and showed no sign of neurotic disorder. She had never suffered from rheumatism or any other severe illness, and the family history appeared to be good. She stated that the contraction began to appear in childhood, shortly after the injury to the arm, but that it had been making more rapid progress in the past eighteen months, during which she had been growing very quickly. After a fruitless attempt to improve the condition by passive motion and splint extension, neither of which was well borne, it was determined to lengthen the tendons by operation. On October 18, 1889, the patient was chloroformed, and it was observed that the deepest anæsthesia caused no relaxation of the contraction. A semicircular incision was made over the inner side of the front of the forearm just above the wrist, the convexity overlapping the tendon of the flexor carpi ulnaris, the horns reaching to a line midway between the radial and ulnar borders of the limb. The flap of integument and fascia was reflected towards the radial side, exposing the inner portion of the flexor sublimis. The tendon of this muscle going to the ring finger was then isolated, transfixed by a fine tenotomy knife, and split longitudinally for a distance of two inches. At each end of the fissure so made the tendon was divided in such a manner as to leave one-half of the split portion attached to the proximal, the other to the distal, end of the tendon. ([Fig. 8.]) The tendon, a very slender one, to the little finger was similarly treated. The effect of this measure upon the contraction was very slight. The portion of the flexor profundus common to the middle, ring, and little fingers was then drawn out and divided after the same method, and the section was followed by immediate and complete extension of the digits. When the fingers were fully straightened, the ends of the divided tendons still overlapped each other to the extent of about a third of an inch, and these portions, in each tendon, were then carefully sewn together by catgut sutures. The wound was then closed and dressed antiseptically (without drainage), and the hand was placed upon a plaster-of-Paris splint; the wrist and fingers being moderately flexed, in order that no undue tension should be thrown upon the united tendons. Healing took place by first intention. At the end of a week the fingers were partially extended, and four days later the extension was made complete, the alteration of position on each occasion being effected without difficulty, and at the expense of little pain. In the middle of the fourth week after the operation a feeble power of flexion had appeared. The patient was discharged on November 13, twenty-six days after the operation. Two months later the condition had much improved, and the voluntary flexion, although still weak, was almost complete as to range. All the tendons had evidently united firmly. She was directed to wear an extension splint at night, and to practise active and passive movement at intervals in the day-time. At the end of a further three months the patient, who lived in the country, came again to London. She had been growing taller in the interval, and said that the contraction had been gradually reappearing. On inquiry it was found that she had neglected her instructions as to extension and motion. Some slight return of the flexion had appeared in the ring and little fingers, and has since been steadily increasing, till it is now almost as great as when she first attended. She has made no adequate effort to oppose the retrogression, but has almost entirely discontinued to use the affected hand. She is still, however, able to move the fingers freely at all the joints. She desires to undergo another operation; but has been advised to obey the directions given to her after the first, and to wait until her growth is quite complete before any more active surgical treatment is undertaken.

Fig. 8.

Diagrams showing Method of Tendon Lengthening.

A. Tendon split longitudinally; B. Section completed by incisions at extremities of fissure; C. Divided tendon elongated and sutured.

The pathology of this case is very obscure. The contraction evidently depended upon a trophic lesion, perhaps due to the injury in childhood, involving the ulnar portion of the flexor profundus, impeding the growth of the muscle, and so preventing it from keeping pace with the normal growth of the bone, but not causing paralysis. The contraction of the flexor sublimis was evidently secondary. The recurrence of the deformity may be explained by the progressively increasing length of the bones of the forearm, the muscle remaining stationary; in other words, the original cause of the condition—the incapacity of the profundus for development—persisted, and led to a return of the effect. Under these circumstances it would obviously be advisable to delay a second operation until the osseous system had reached its permanent proportions. The operation I believe to be original; and so far as the restoration of continuity of tendon is concerned, the result proved a complete success. It might possibly be applied with advantage in various conditions as a substitute for tenotomy.

The operation was performed independently by Professor Keen,[3] about a twelvemonth after this case, and has since been adapted to lengthening and shortening of tendons by Drs. H. A. Wilson,[4] Colgan,[5] and Ochsner, in America.

Case 2.—H. L., a youth aged seventeen, was admitted as an out-patient at St. Thomas’s Hospital, in November 1890. He complained of a contraction of the thumb and fingers of the right hand of three years’ duration. The condition began without apparent cause, and has increased progressively. He was fairly well grown, but of somewhat delicate aspect. He had an attack of rheumatic fever at the age of six, but had since been in good health. The contraction was of the same nature as that in Case 1, but less in degree, and involved all the digits. The hand was well formed, and all the bones, joints, and muscles were normal. The power of finger extension was complete during flexion of the wrist. The forearm flexors are rather small, but there is no distinct atrophy; the movements at the wrist, elbow, and shoulder are perfect. He said that the defect crippled him greatly for work, and that forcible extension caused pain in the forearm. He was instructed to carry out a system of massage, with active and passive movements of the fingers and wrist.