Total Knee Replacement with an Oxidised Zirconium Femoral Component: Ten Year Survivorship Analysis

OBJECTIVES: Oxidized zirconium was introduced as a material for femoral components in total knee replacement (TKR) to reduce polyethylene wear. However the long term survival of this prosthesis is not known. METHODS: A series of 303 consecutive oxidised zirconium TKR were performed over a 3 year period and prospectively included in a database. Subjects were assessed preoperatively and 10 years after TKR. Outcome measures included the Western Ontario and McMaster Universities Osteoarthritis Index, Knee Injury and Osteoarthritis Outcome Score (KOOS), radiographic evaluation and a patient satisfaction. RESULTS: A total of 303 consecutive TKRs were performed in 278 patients with a mean age of 68 years (range 45 to 89 years). The ten year survival rate from the Kaplan–Meier predicted survivorship was 97% (95% CI 94 - 99) with revision for any reason as the endpoint. There were no revisions for loosening, osteolysis or implant failure. There was a significant improvement in all components of the WOMAC score at final follow up (p<0.001). The mean individual components of the KOOS score for symptoms (82.4 points), pain (87.5 points), activities of daily life (84.9 points) and quality of life (71.4 points) were all at higher end of the scale. CONCLUSION: The oxidized zirconium TKR is associated with favourable survival rates and excellent functional outcomes at ten years.