Favorable long-term results of prosthetic arthroplasty of the knee for distal femur neoplasms.

UNLABELLED: We evaluated implant survival, late complications prompting reoperation and functional outcome in long-term (> 5 years) survivors of bone neoplasms of the distal femur treated with osteoarticular resection and segmental rotating hinge total knee arthroplasty. We retrospectively reviewed 83 patients who survived more than 5 years after the first procedure. Seventy-four of the 83 patients have retained a mobile knee joint. At a median followup of 146 months (range, 62-252 months), 22 patients required 26 additional procedures for a prosthesis-specific event (n = 24) or tumor recurrence (n = 2) after reaching 5-year followup. Aseptic loosening (n = 7) and component breakage (n = 2) occurred between 5 and 10 years. Polyethylene wear (n = 12) occurred only after 10 years. One late tumor recurrence at 62 months prompted amputation. All other patients retained a mobile knee joint. Functional outcome was excellent with a median Musculoskeletal Tumor Society score of 88% and a median Toronto Extremity Severity Scale score of 94%. Patients with bone neoplasms who survive more than 5 years after limb salvage with a segmental rotating hinge total knee arthroplasty can expect to retain a mobile knee joint and function consistently at a high level. LEVEL OF EVIDENCE: Therapeutic study, Level III-2 (retrospective cohort study). See the Guidelines for Authors for a complete description of levels of evidence.