Abstract
To report a 15-year survival analysis of the Oxford Medial Unicompartmental Knee Arthroplasty (Oxford UKA) in an independent series.
We report the results of a series of 420 Oxford UKAs performed between 1983 and 2000. Indications for surgery were primary antero-medial osteoarthritis of the knee with an intact ACL, correctable varus deformity of < 15° and < 15° fixed flexion deformity. The state of the patello-femoral joint was not used as a selection criterion. Patients were contacted by a postal questionnaire or by telephone. The outcome of all 420 knees was established, with none lost to follow-up. Seventy-six knees were in patients who had died and the state of each arthroplasty was determined from hospital and GP records.
Seventeen patients (4%) had required revision. Indications for revision were lateral compartment arthrosis (7), component loosening (4), bearing dislocation (4) and infection (2). There were no failures for polyethylene wear. Cumulative survival at 15 years was 94.3% [95% CI 3.8%]. The worst case scenario was 94.3% as none were lost to follow-up.
The results from an independent series are important, as they avoid bias. The 15-year results of this independent series are better than any other reported series of unicompartmental device at 15 years and as good as the published independent 15 year survival results for total knee arthroplasty. The data illustrates that excellent long-term survival can be achieved with the Oxford UKA, allowing patients to benefit from the advantages that unicompartmental arthroplasty offers. We believe that provided patients are selected appropriately, this device provides the treatment of choice for anteromedial osteoarthritis of the knee.
The abstracts were prepared by Mr Simon Donell. Correspondence should be addressed to him at the Department of Orthopaedics, Norfolk & Norwich Hospital, Level 4, Centre Block, Colney Lane, Norwich NR4 7UY, United Kingdom.
