Complications following metatarsal lengthening by callus distraction for brachymetatarsia

We performed six metatarsal lengthenings in four patients for brachymetatarsia of the fourth toe by callus distraction from 1991 to 1995. Healing was achieved in all cases. The average amount of lengthening was 30% (range, 15-41%) of the original length. The average healing index was 82 days/ cm (range, 66-113 days/cm). After the operation, range of movement of the metatarsophalangeal joint decreased in all cases (120° before and 57° after surgery). In two cases in which the lengthening exceeded 40% of the original length, stiffness of the joint (20° and 0° each) and joint deformity occurred. These two cases also had angulation of the metatarsal. Corrective osteotomy and release surgery was performed in one case. Angulation of the metatarsal was corrected, but the range of movement of the joint did not much recover after surgery. Another case was left untreated because the patient had no complaints. In metatarsal lengthening by callus distraction, the amount of lengthening should not exceed 40% of the original length.