Entin reconstruction for duplication of ulna (mirror hand). A, Appearance of mirror hand with extra digits. Digits I and III were discarded; digit II was retained for pollicization. B, Pollicization of digit II. This digit was properly positioned by osteotomy through base of its metacarpal and by intermetacarpal graft cut from metacarpal of discarded digit III. C, Filleted skin of digit III was used as flap to cover space created by pollicization.