[Lengthening middle hand and finger segment stumps by external distraction devices following traumatic amputations and in congenital abnormalities].

Since November 1984, lengthening of metacarpals and digital phalanges by a distraction apparatus has been performed in six metacarpal bones and four phalangeal bones in nine patients (four females, five males). The age ranged from 14 to 59 years (average 36). The follow-up period was from two to 28 months (average 16). Lengthening was performed by two kinds of external distraction devices, the Ikuta external fixateur for metacarpals and the mini-Hoffmann-device for phalanges. The achieved elongation of the metacarpal bones varied from 26 mm to 30 mm (average 28.8 mm), and of the digital phalanges from 10 mm to 17 mm (average 13.5 mm). During the operation, the bone was distracted primarily about 5 mm and thereafter it was gradually distracted at a rate of 0.5 to 1 mm per day. Blood supply and subjective complaints were examined carefully. During distraction, following complications were observed: Fracture of grafted bone, necrosis of free grafted skin, rupture of a tendon with neglected lesion and delayed spontaneous bone union between the fragments. It is emphasized that skin, tendons, and other soft tissues around the thumb and fingers to be elongated should be intact and that the gap should be filled with an en-bloc bone graft. This facilitates early union in spite of a relatively short period of immobilization. Because of the relative simplicity of the method, no microsurgical technique is required. The main advantage of the procedure is that the lengthened digit retains its original sensation, vascular supply and some mobility. It is a useful procedure especially when a patient does not want to sacrifice another digit.