Medium term results of the cementless Oxford mobile bearing medial unicompartmental knee replacement.

backgroundMedial Unicompartmental Knee Replacement (UKR) has well-documented benefits over Total Knee Replacement in the treatment of anteromedial osteoarthritis of the knee. There has been an increasing move from cemented to cementless UKR over the last decade. This non-design centre study assesses the initial experience using the cementless Oxford medial partial knee replacement and provides medium term revision data, as well as Patient Reported Outcome Measures (PROMs).

methodsA cohort of 200 consecutive patients undergoing medial UKR using the cementless Oxford were identified from our knee groups prospectively collected database. Cases were performed in a single centre under the care of one of four surgeons. All patients were beyond the 5-year minimum timepoint following UKR surgery in order to produce medium term results, at a mean of 7.9 years. Eligible patients completed a postal questionnaire to collect PROMs: Oxford Knee Score, WOMAC and modified American Knee Society Score questionnaires in January 2020 and had their clinical records reviewed.

resultsThe survivorship in our cohort was 94.5% at a mean follow up of 7.9 years following surgery. There were 11 re-operations in total with a three percent risk of re-operation within the first 18 months following surgery. There was a sustained improvement in Oxford Knee Score with a near 20 points improvement on pre-operative scores.

conclusionsOur results provide further evidence that partial knee replacements using the cementless Oxford produce good clinical outcomes. Revision rates are similar to those published in the National Joint Registry. LEVEL OF EVIDENCE: III.