Distal femur osteosarcoma in an adolescent: Limb salvage with cryosurgery-recycled bone, hemi knee replacement, and ORIF-A case report.

INTRODUCTION

This report presents a rare case of distal femoral osteosarcoma in an 11-year-old boy, managed through a hybrid limb-salvage approach combining cryosurgery-recycled bone, hemi knee arthroplasty, and internal fixation. The objective is to detail the surgical technique and assess short-term functional outcomes, particularly in adolescents with juxta-articular osteosarcoma.

PRESENTATION OF CASE: The patient presented with a three-month history of progressive right knee pain and swelling. Radiographs indicated classic osteosarcoma features, including a sunburst pattern and Codman's triangle. In the absence of biopsy and advanced imaging, diagnosis was made clinically and radiologically. Following 2 cycles of neoadjuvant chemotherapy, wide resection of the tumor was performed. The excised bone was treated with liquid nitrogen cryoablation and reimplanted as a recycled autograft. Knee joint reconstruction was completed using a cemented polyethylene hemiarthroplasty on the tibial side, with the femoral segment stabilized using a lateral locking plate. Postoperative recovery was smooth, with the patient achieving excellent functional outcomes within six months. No recurrence or metastasis was noted during follow-up.

DISCUSSION: This case demonstrates the clinical feasibility of combining cryo-treated autograft and hemiarthroplasty for biologic limb reconstruction in pediatric patients. The technique preserves native anatomy, reduces donor site complications, and provides a cost-effective alternative to megaprostheses-making it particularly suitable for low-resource settings.

CONCLUSION

Cryosurgery-recycled autograft combined with hemi knee replacement and internal fixation is a promising limb-salvage strategy offering favorable oncological and functional outcomes in managing pediatric osteosarcoma.