Correction of the paralytic claw-thumb by two-tailed transfer of the superficialis tendon through a window in the flexor retinaculum.

The results of correction of 39 paralytic claw-thumbs in 34 leprosy patients with combined ulnar and median nerve paralysis by transfer of the flexor superficialis tendon through a small window in the flexor retinaculum are reported. The motor tendon was split into two slips, one passed lateral and the other volar to the metacarpophalangeal joint of the thumb. Both slips were sutured to the tendon of the extensor pollicis longus. The volar slip was used in an attempt to restore muscle balance at the metacarpophalangeal joint. Satisfactory abduction was obtained in 90 percent of the cases, and excessive tip flexion during abduction-opposition was abolished in 85 percent of the cases. However, undesirable flexion of the proximal phalanx occurred in 10 thumbs when held actively in abduction-opposition.