OXFORD MENISCAL BEARING KNEE VERSUS THE MARMOR KNEE IN UNICOMPARTMENTAL ARTHROPLASTY FOR ARTHROSIS - A SWEDISH MULTICENTER SURVIVAL STUDY

In the Swedish Knee Arthroplasty Study, all 699 Oxford meniscal bearin g cemented unicompartmental prostheses (Biomet, Bridgend, UK) were ide ntified and analyzed regarding failure pattern and compared with all M armor prostheses (Smith & Nephew Richards, Orthez, France) and with a time-, age-, and sex-marched subset of Marmor prostheses using surviva l statistics expressed as cumulative revision rates. After 1 year ther e was already a higher rate, and after 6 years the rate of the Oxford group was more than twice that of the Marmor group. There were 50 revi sions in the Oxford group: dislocating, meniscus in 16, loosening of t he femoral component in 6, tibial component in 4, both components in 4 , contralateral arthrosis in 10, infection in 4, and technical failure with instability, pain, and/or impingement of the meniscal bearing an terior in the femoral condyle in 6. It is still unclear if the design with the sliding menisci will, in the long turn, reduce wear and loose ning, thereby compensating for the initially inferior results. It is r ecommended that until this question is clarified, the Oxford knee shou ld be used on a limited scale for long-term comparative studies only.