Chipping corrective osteotomy for reconstruction of malunion with angular deformity of the lower extremity: Technical tips and preliminary clinical results.

Abstract

Significant functional disturbance, deformity, and malalignment may occasionally develop after healing of a fracture, especially one involving the lower extremities. This study sought to provide preliminary evidence of the effectiveness of chipping corrective osteotomy (CCO), which does not require autologous bone grafting, for treating malunion with lower extremity angular deformity. We retrospectively reviewed clinical and radiologic results of 6 male patients (median age 48.5 years) treated with CCO for femoral and tibial malunion (4 femurs, 4 tibias) with angular deformity in the coronal plane. In performing CCO, we applied a temporary external fixator to correct the deformity; definitive fixation was performed using a locking plate. Time to consolidation after the surgery was recorded. The Mikulicz line was evaluated before surgery and at final follow-up in each patient to confirm a change in alignment of the affected lower extremity. We measured the score taken as the ratio of the distance between the medial tibial joint surface and the Mikulicz line to the width of the tibial plateau. Median follow-up duration was 34 months. Bone healing was achieved by a median of 3.5 months postoperatively. Correction of the mechanical axis in the affected lower extremity was achieved in all 6 patients. Median score by the length from the tibial medial joint surface to the Mikulicz line to the tibial plateau width was 7.7% preoperatively and 25.7% at final follow-up. These preliminary findings suggest that CCO is potentially useful for treating malunion with lower extremity angular deformity. Further evaluation in a larger series is needed to clarify the usefulness of CCO in correction of angular malunion.