Madelung's Deformity of the Wrist.—In 1878, Madelung called attention to a deformity also called sub-luxation of the hand, in which the lower articular surface of the radius is rotated so that it looks towards the palm; there is palmar displacement of the carpus, and the lower end of the ulna projects on the dorsum. The cause of the condition is obscure, but it is met with chiefly in young women with slack ligaments, whose laborious occupation or athletic pursuits subject the hand and wrist to long-continued or repeated strain. It is as frequently unilateral as bilateral and may recur in successive generations. There is a good deal of pain, the grasping power of the hand is impaired, and dorsiflexion is considerably restricted. The deformity disappears on forcible traction, but at once reappears when the traction is removed. A wristlet of poroplastic or leather extending from the mid-forearm to the knuckles is moulded to the limb in the corrected position, and is taken off at intervals for massage and exercises.
When operative treatment is called for, it takes the form of osteotomy of the radius and ulna about an inch or more above their articular surfaces.
Congenital dislocation of the wrist is rare.
Deformities of the Fingers.—Various forms of congenital dislocation of the fingers are met with, but they are of little clinical importance, as they interfere but slightly with the usefulness of the digit affected.
Congenital lateral deviation of the phalanges is more unsightly than disabling; it is met with chiefly in the thumb, in which the terminal phalanx deviates to the radial or to the ulnar side in extension; the deviation disappears on flexion.
Congenital contraction of the fingers is comparatively common. It is an inherited deformity, and is often met with in several members of the same family. It most frequently affects the little or the ring and little fingers ([Fig. 172]), and is usually bilateral. The second and third phalanges are flexed towards the palm; the first phalanx is dorsiflexed, this being the reverse of what is observed in Dupuytren's contraction. Duncan Fitzwilliams suggests that it should be called “hook-finger,” and that it is probably due to imperfect development of the anterior ligament of the first inter-phalangeal joint. He has observed it in association with laxity of the ligaments of the other joints of the body.
Fig. 172.—Congenital Contraction of Ring and Little Fingers.
The affection is usually disregarded in infancy and childhood as being of no importance. In young children, the deformity is corrected by wearing a light splint fixed with strips of plaster, or a piece of whalebone or steel inside the finger of a glove. In older children, the finger may be straightened by subcutaneous division of the ligament over the palmar aspect of the base of the middle phalanx, or failing this by lengthening the flexor tendons and resecting a wedge from the dorsal aspect of the first phalanx close to the inter-phalangeal joint.