Treatment of volar instability of the metacarpophalangeal joint of the thumb by volar capsulodesis.

The metacarpophalangeal joint bears most of the stresses to which the thumb ray is subjected. Instability of this joint results in considerable functional impairment of the hand. Volar instability may be secondary to trauma, rheumatoid arthritis, or adduction spasms in cerebral palsy. The resulting hyperextension causes pain and weakness of pinch (Fig. 1). Various techniques have been described to correct this deformity. We prefer a volar capsulodesis as first described by Filler (1976), in which the whole volar plate is reinserted. Detailed knowledge of the complicated volar anatomy is essential. We have treated eight patients (two bilaterally) with this technique, all with satisfactory results.