Madelung's Deformity of the Wrist

Abstract

MADELUNG'S deformity of the wrist is a rare condition, usually bilateral, developing at the distal end of the forearm of young individuals between the ages of 8 and 20 years—80 per cent of such deformities appear between the ages of 11 and 15 years. The deformity is essentially an anterolateral curvature of the distal third of the radius, with dorsal prominence of the joint end of the ulna. Contrary to early descriptions, it is not associated with an irreducible dislocation of the wrist. The lesion progresses slowly and by the end of one or two years the deformity is complete. During the active developmental stage, pains may or may not be present. If there is discomfort from pain or ache, it may be aggravated by forced movement, chiefly by extension. The anatomical changes are best seen in roentgenograms which include the hand and the entire forearm. There is bowing of the lower third of the radius, usually dorsal and lateral. The articular surface is tilted medially toward the volar side and slightly rotated inward and backward, and the carpus is thrown forward. The increase of the axial curve of the radius, especially along its medial aspect, results in marked bowing with shortening of the length of the bone. The ulna is not primarily affected, but, due to the shortening of the radius, the distal joint end of the ulna is made to override the carpus and it becomes unduly prominent, as is demonstrated in lateral views. In 96 per cent of the cases this overriding takes place dorsally and the carpus is displaced anteriorly. Rarely, as in Stetten's case, the reverse occurs. The relative overgrowth of the ulna is of the greatest importance and very often gives rise to the first clinical manifestation of the deformity. Especially characteristic is the widening of the interosseous space due to the exaggeration of the normal flexor concavity of the distal end of the radius. The arrangement of the carpal bones presents more or less alteration, chiefly as regards the static relationship between the distal end of the forearm and the proximal carpal series, while the individual bones mostly remain normal in shape and outline. Schnek and Melchior have drawn attention to more or less marked changes in the declination angle of the joint surface of the radius with a corresponding pyramidal arrangement of the proximal carpal bones (Figs. 1 and 2). Köhler points out that instead of the normal slightly curved arrangement of the carpals, paralleling the joint fork of the forearm, there is a V-shaped arrangement with the os lunatum forming the vertex of the triangle. This is mainly observed in cases of bilateral true Madelung's deformity. Recent papers have confirmed this finding and have further pointed out the presence of low-grade changes of a similar nature in the contralateral joint in cases in which clinically the deformity was only unilaterally manifest.