Techniques for small-bone lengthening in congenital anomalies of the hand and foot

The purpose of this study is to analyse three different lengthening techniq ues used in 31 small bones for congenital malformations of the hand and foo t: 15 metacarpals, 12 metatarsals, 1 foot stump and 3 spaces between a prev iously transplanted phalanx end of the carpus or the metacarpal. Progressiv e lengthening with an external fixator device was performed in 23 cases: th e callus distraction (callotaxis) technique was used in 15 cases, whereas i n the other 8 cases the speed of lengthening was faster and the defect brid ged with a bone graft as a second stage. In another eight cases, a one-stag e lengthening was performed. In the callotaxis group, the total length gain ed ranged from 9 mm to 30 mm and the percentage of lengthening obtained (co mpared with the initial bone length) averaged 53.4%; in the fast lengthenin g group, the length gained ranged from 8 min to 15 mm, and the average perc entage of lengthening was 53.1%; and in the one-stage group, the length gai ned ranged from 7 mm to 15 mm, and the average percentage of lengthening wa s 43%. The overall complication rate was 22.5%.