Femoral lengthening by callus distraction and cortical apposition (Z-osteotomy).

Nine patients underwent femoral lengthening by callus distraction with cortical apposition (Z-osteotomy). The average amount of lengthening was 4.8 cm (range, 2.9-6.0 cm). The average time of external fixator use was 70 days (range, 33-100 days). The average time for using the cast brace was 3.5 months. All patients had complete union. No patient required bone grafting. No patient had premature consolidation of the osteotomy. Complications included cellulitis around the pins in 2 patients, transient peroneal nerve palsy in 1 patient, and fracture after removal of external fixator in 2 patients. In this procedure the alignment and rotation is controlled by a strong external fixating device. The large area of cortical contact after z-osteotomy assists in rapid union of the distracted bone.