Neuropathic arthropathy as a possible cause of failure of a whole joint allograft. A case report.

This report illustrates the fate of a whole joint allograft in a 23-year-old male with chondrosarcoma of the right hip. An extraarticular resection of the right proximal femur and surrounding pelvis was performed. Reconstruction was carried out with a fresh-frozen cadaveric allograft of articulated proximal femur and acetabulum with the capsule intact. Excellent union at the junction of host bone with the allograft was demonstrated roentgenographically 12 months later. Nineteen months after the operation, as weight bearing proceeded, sudden onset of instability of the joint occurred without pain. Collapse of the allograft with partial dissolution of the femoral head and acetabulum were observed roentgenographically. Reconstruction was achieved with a prosthetic implant. The roentgenographic and pathologic features of the allograft are suggestive of neuropathic arthropathy; however, the possibility of allograft rejection cannot be excluded but seems unlikely.