TWENTY-YEAR SURVIVAL AND 10-YEAR CLINICAL RESULTS OF THE MEDIAL OXFORD UNICOMPARTMENTAL KNEE ARTHROPLASTY.

Abstract

Aim: This paper presents the 20-year survival and 10-year clinical follow-up results from the entire series of all medial Oxford meniscal bearing unicompartmental knee arthroplasties performed in a single centre in Sweden, between 1985 and 2004.

Method: Patients were contacted and information about the state of the knee collected. Revision surgery was used in the life-table survival analysis performed. For the entire cohort clinical follow up at 10-years is routinely performed, using the HSS knee score.

Results: The entire group comprised of 683 knees in 572 patients. The mean age at implantation was 69.7 (range 48–94). There had been 30 revision procedures: 8 for lateral arthrosis, 7 for component loosening, 3 for infection, 6 for bearing dislocation, 1 for bearing fracture and 5 for unexplained pain. The 10-year, 15-year and 20-year survival (all cause revision) were 94.1 % (CI 2.9, 237 at risk), 93.5% (CI 4.6, 101 at risk) and 92.3% (CI 15.1, 11 at risk) respectively. From the patients reviewed clinically the mean pre-operative HSS knee score was 57 (95% CI 1), compared to 87 (95% CI 1) at 10-years. Using HSS criteria the results were: 68% excellent, 23% good, 6% moderate and 2% poor.

Conclusion: The results show that this mobile bearing unicompartmental prosthesis offers patients excellent clinical results during the first decade and is durable during the second decade after implantation.