[An unusual form of macrodactyly]

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 joints. The metacarpo-phalangeal joint and interphalangeal joints in an abnormal position. This results 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 are being assessed. The literature is reviewed and the different modes of treatment utilised in such a malformation is presented. A relation between macrodactyly and lipomatous macrodystrophy is considered.