Femoral Elongation Using Distraction Osteogenesis: Is It Possible in Patients with a Previous Massive Femoral Bone Allograft?

Primary bone sarcomas in children frequently involve the distal femur, and limb-salvage resection often results in loss of the distal femoral physis, leading to progressive limb-length discrepancy (LLD). Biological reconstruction with massive allografts restores bone stock but does not prevent LLD. To describe the surgical technique and clinical outcomes of proximal femoral lengthening using distraction osteogenesis over an intramedullary nail in pediatric patients who developed significant LLD following distal femoral tumor resection and osteoarticular allograft (OA) reconstruction. Between 2000 and 2020, four pediatric patients with LLD ≥50 mm following distal femoral resection and OA reconstruction underwent proximal femoral lengthening. Clinical and radiographic outcomes were assessed using the Paley criteria. Mean follow-up was 6.1 years. Proximal femoral lengthening was performed using distraction osteogenesis over an IM nail in patients with established LLD following distal femoral growth plate loss. Through a lateral proximal femoral approach, the femur was reamed and an IM nail inserted. An external fixator was applied exclusively to autologous bone, followed by a proximal femoral osteotomy. Gradual distraction began seven days postoperatively at 1 mm/day. After achieving the planned length, the nail was locked proximally and the external fixator removed. Mean lengthening was 61 mm. All patients achieved radiographic consolidation. Functional outcomes improved, with predominantly excellent results and no major procedure-related complications. Proximal femoral lengthening over an IM nail is a reliable technique for correcting LLD after distal femoral tumor resection and OA reconstruction, combining biological restoration with reduced morbidity.