Treatment of a locally advanced diaphyseal osteoblastic osteosarcoma: resection and reconstruction (A case report)

Strictly diaphyseal osteosarcoma is rare and poses complex challenges for intercalary reconstruction following tumor resection. We report the case of a 20-year-old female patient presenting with a locally advanced osteoblastic osteosarcoma of the left femoral diaphysis. Imaging revealed a 9 cm mass infiltrating adjacent soft tissues without neurovascular involvement. The staging workup was negative for metastasis. Faced with the dilemma of reconstructing a massive bone defect, a wide oncological resection followed by defect filling with surgical cement and locked plate osteosynthesis was preferred. Histopathological examination confirmed clear margins and tumor necrosis evaluated at Huvos grade II [2]. This two-stage approach (Masquelet-type technique) provides immediate mechanical stability while minimizing the risk of biological graft loss in the event of local recurrence [4].