Knee Replacement Implants Have Similar Performance

No difference in outcomes between oxidized zirconium, cobalt-chromium femoral components

TUESDAY, April 26 (HealthDay News) -- There are no significant differences in the clinical outcomes of total knee arthroplasty using either oxidized zirconium or cobalt-chromium femoral components in short-term or long-term follow-up, according to a study published in the April 6 issue of The Journal of Bone & Joint Surgery.

Catherine Hui, M.D., from the North Sydney Orthopaedic and Sports Medicine Centre in Australia, and colleagues compared the performance of oxidized zirconium femoral components with cobalt-chromium and determined whether the use of oxidized zirconium components had adverse clinical effects. Forty patients with primary osteoarthritis underwent simultaneous bilateral cruciate-retaining total knee arthroplasty. For each patient, the two knees were randomly assigned to receive either the oxidized zirconium femoral component or the cobalt-chromium component.

The investigators found no significant postoperative differences in the clinical, subjective, and radiographic outcomes between the oxidized zirconium and cobalt-chromium implants at five days; six weeks; and one, two, or five years. A follow-up five years after surgery showed that significantly more patients preferred the cobalt-chromium knee compared with the oxidized zirconium knee (38 versus 18 percent), and 44 percent of the patients had no preference. Oxidized zirconium femoral implants showed no adverse events.

"Five-year outcomes after total knee arthroplasty with oxidized zirconium and cobalt-chromium femoral components showed no significant differences in clinical, subjective, and radiographic outcomes. Patients had no preference or preferred the cobalt-chromium prosthesis to the oxidized zirconium prosthesis at the time of the five-year follow-up," the authors write.

Several of the study authors disclosed financial relationships with Smith & Nephew.

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