Successful conversion of a total femur knee-arthrodesing prosthesis to a functional knee construct—a case report

Katznelson and Nerubay (1980) reported their experience with 5 cases of total femur endoprosthetic reconstruction in Acta Orthopaedica Scandinavica almost 3 decades ago. Their patients had primary bone sarcomas of the distal femur, the extent of which necessitated total femur resection in order to achieve wide surgical margins. Design features of the prosthesis they used for reconstruction included an Austin-Moore type head, a stabilizing platform that lay on the tibial plateau, and a long tibial stem (Figure 1). This prosthesis preserved hip motion but left the patient with a fixed knee. In 1999, a 30-year-old woman who had been similarly treated by the same authors in 1982 was referred to our institution with the request to improve her knee function. At that time she was an independent, unmarried social worker and was extremely frustrated by her inability to flex her knee. She had an osteosarcoma of the distal femur and was free of disease after surgery combined with pre- and postoperative chemotherapy. Physical examination upon referral showed considerable atrophy of all thigh muscles, but their contraction capability was preserved and sufficient muscle tissue was left for additional prosthetic coverage. We decided to replace a segment of her prosthesis to restore knee motion.