Extensor indicis opposition transfer in the ulnar and median palsied thumb in leprosy.

Twenty seven opponensplasties for ulnar and median paralysis in 25 leprosy patients were performed using extensor indicis proprius. An additional transfer of the radial half of flexor pollicis longus to extensor pollicis longus was done to stabilize the metacarpophalangeal joint of the thumb. The biomechanical aspects of extensor indicis proprius tendon transfer were studied and results evaluated using various anatomical and functional parameters. Extensor indicis proprius provides adequate strength to position the thumb. However, sometimes it does not reach its new insertion. There is no significant deficit at the donor site but in a few cases the index finger may lose its capability for independent extension and sometimes a proximal interphalangeal joint contracture may develop.