Bone Allograft Prosthesis Composite to Revise a Failed Massive Allo-Prosthesis: Case Report and 10 Years of Follow-Up.

An 18-year-old male patient with a high-grade osteosarcoma was initially treated with resection and reconstruction using an osteochondral allograft. The allograft collapsed after five years, and thus a revision with a constrained knee prosthesis was performed. After one year, the implant failed due to a fracture, requiring another revision with a new allo-prosthetic composite. The long-term results were satisfactory. Allo-prosthetic composites may offer good long-term results after sarcoma resection. The failure of a massive bone allograft does not preclude the use of another allograft to maintain the bone stock and preserve the function.