New strategy for shortening the consolidation period in distraction lengthening of phalanges or metacarpal bone

Abstract

Distraction lengthening of digits enhances hand function in patients with congenital phalangeal defects or traumatic hand amputations. Although callotasis is a useful distraction lengthening method, it is challenging and often results in various complications and prolonged fixation. Based on our experiences, we attempted to develop innovations to reduce the fixation period. We included 12 digits from nine patients with digital bone defects; lengthening was performed on seven proximal phalanges and five metacarpal bones using an Ilizarov mini-fixator device. In three digits, cancellous bone grafting within the cavity of the distraction callus, concomitant with internal fixation using an intramedullary screw, was performed to shorten the Healing Index. The mean achieved lengthening was 24 mm for proximal phalanges and 22 mm for metacarpal bones, with a Healing Index of 37.9 and 42.6 days/cm, respectively. Additionally, the Healing Index was significantly shorter in the three digits treated with cancellous bone grafting and internal fixation (mean 27.0 days/cm) than in the nine with no bone grafting (mean 44.1 days/cm). Major complications included early bone union, insufficient fingertip skin, and callus fractures during the consolidation period, affecting two, two, and one patient, respectively. Bone grafting within the distraction callus cavity promotes rapid bone formation, while internal fixation enables earlier removal of external fixators, thereby shortening the Healing Index.