[Thumb reconstruction after amputation injuries]

Reconstruction of the thumb following amputation injuries: In this review of the different methods of thumb reconstruction following traumatic amputation, the procedures applicable in the primary care of the hand are first mentioned and demonstrated: replantation of a thumb, cover of a distal amputation with a neurovascular flap and salvage of a thumb with intermediate segmental loss. In most instances the thumb reconstruction is performed as a secondary procedure. The indication and the selection of the method depend upon the level of amputation, the dominance of the injured hand, and the presence of other injuries to the same hand as well as age, sex, occupation, and intelligence of the patient. There are several different operative methods: 1) Deepening of the first web space (phalangisation of the first metacarpal) by means of a Z-plasty with proximal transposition of the insertion of the adductor pollicis muscle. 2) Lengthening of the first metacarpal with a bone graft either as Gillies cocked hat procedure or as interposition following distraction of the osteotomized two parts of the metacarpal in one stage or as continuous distraction (Matev). --Both methods are performed often in combination and are indicated in loss of the thumb at the base of the proximal phalanx or at the MP-joint in the non-dominant hand or in unskilled workmen. 3) Osteoplastic methods with bone graft, tube pedicle and neurovascular island flap have the risk of absorption of the bone graft and therefore more limited indications. These are given in unskilled manual workers with no other injured digits and in multiple loss of digits where toe transfer is not appropriate. 4) Transposition of another intact or partially amputated digit on a neurovascular pedicle. The two different operative techniques depend upon the presence or loss of the first metacarpal and the thenar muscles. The indication is given in amputations at any point proximal to the base of the proximal phalanx in either hand of most women, children and skilled workers. 5) Free toe transfer is indicated if there is not any other finger or part of a finger available and the first metacarpal is preserved. In exceptional cases a free transfer of a digit of the contralateral hand is possible.