From 1990 to 1997, callus distraction of the first metacarpal bone was performed on 34 patients with a traumatic amputation of the thumb, if replantation was not possible. After a period of 7 +/- 11 months (range, 1-48),a corticotomy and continuous distraction with an external fixator was carried out. Of the patients, 31 (91%) were reviewed after treatment. The follow-up period range was 41 +/- 32 months. With this method,the average lengthening of the thumb was 78% in comparison to the uninjured side. Complications were rupture of the callus in one case, four patients suffered a superficial wound infection, and seven patients showed pin tract infection without osteitis. At follow-up examination, 20 patients (64.5%) showed excellent, 9 (29%) good and 2 patients (6.5%) unsatisfying results.