Long-term results after partial knee arthroplasty with the Oxford Knee

Abstract

Introduction Osteoarthritis of the knee is one of the most common reasons for disability, especially in elderly people. Surgical treatment is still controversial. Unicompartmental knee arthroplasty, i.e. partial knee arthroplasty, using the Oxford Knee has been available since 1983. The aims of the study were to compare the 10 years survival rate in the designers´ series, to determine the 10 year survival rate and clinical outcome in younger patients, to assess the outcome in patients with spontaneous osteonecrosis of the knee, to report the results in patients who were operated on earlier operated with high tibial osteotomy, to report long-term survival results more than 20 years after primary procedure and to assess the reconstruction requirements and early clinical outcome following revision of the Oxford Knee to total knee arthroplasty. Methods and results Patients in different age with painful focal antero-medial osteoarthritis stage I-III according to the Ahlbäck classification were operated on using unicompartmental arthroplasty with the Oxford Knee. Clinical and radiological assessments were performed preoperatively, as well as after 3 months, and 1, 6, 10, 15 and finally more than 20 years postoperatively. Hospital for Special Surgery score (HSS score 0-100) and Oxford Knee Score (OKS 0-48) were used to evaluate the outcome. The 10-years survival was found to be comparable to the designer’s series. Accordingly, there was no obvious contraindication for the use of the Oxford Knee in younger patients. The clinical outcome and survival was similar in knees with primary osteonecrosis in terms of short- and medium-term results as in patients with osteoarthritis. A previous high tibial osteotomy should be considered to be a contraindication to the use of the Oxford Knee. The revision of the Oxford Knee is technically easier and the results superior to the revision of total knee replacement. Conclusion With correct indication and good surgical technique, the Oxford Knee partial arthroplasty can be considered a useful treatment in patients with antero-medial osteoarthritis of the knee.