[An unusual form of macrodactylia]

The authors report a rare case of macrodactyly of the thumb in a 36 year old woman. The hypertrophy predominates on the epiphyseal tissue with complete ankylosis of the trapezo-metacarpal metacarpo-phalangeal, and interphalangeal joints in an abnormal position. This results in total functional incapacity of the thumb. The cosmetic and psychological impact are important to consider. Treatment consisted of two operative procedures. First a silastic implant for the trapezo-metacarpal joint and an arthrodesis of the metacarpophalangeal joint in a normal position was done. Three months later, the volume of the thumb was reduced by a longitudinal bone resection. The functional and cosmetic result is assessed. The literature is reviewed and the different modes of treatment utilized in such a malformation are presented. A relation between macrodactyly and lipomatous macrodystrophy is considered.