title: The clinical outcome of minimally invasive Phase 3 Oxford unicompartmental knee arthroplasty: a 15-year follow-up of 1000 UKAs.
abstract: There have been concerns about the long-term survival of unicompartmental knee arthroplasty (UKA). This prospective study reports the 15-year survival and ten-year functional outcome of a consecutive series of 1000 minimally invasive Phase 3 Oxford medial UKAs (818 patients, 393 men, 48%, 425 women, 52%, mean age 66 years; 32 to 88). These were implanted by two surgeons involved with the design of the prosthesis to treat anteromedial osteoarthritis and spontaneous osteonecrosis of the knee, which are recommended indications. Patients were prospectively identified and followed up independently for a mean of 10.3 years (5.3 to 16.6). At ten years, the mean Oxford Knee Score was 40 (standard deviation (sd) 9; 2 to 48): 79% of knees (349) had an excellent or good outcome. There were 52 implant-related re-operations at a mean of 5.5 years (0.2 to 14.7). The most common reasons for re-operation were arthritis in the lateral compartment (2.5%, 25 knees), bearing dislocation (0.7%, seven knees) and unexplained pain (0.7%, seven knees). When all implant-related re-operations were considered as failures, the ten-year rate of survival was 94% (95% confidence interval (CI) 92 to 96) and the 15-year survival rate 91% (CI 83 to 98). When failure of the implant was the endpoint the 15-year survival was 99% (CI 96 to 100). This is the only large series of minimally invasive UKAs with 15-year survival data. The results support the continued use of minimally invasive UKA for the recommended indications.
authors.affiliation: NDORMS, University of Oxford, Windmill Road, Oxford OX3 7LD, UK.
authors.forename: H
authors.initials: H
authors.lastname: Pandit
authors.affiliation: NDORMS, University of Oxford, Windmill Road, Oxford OX3 7LD, UK.
authors.forename: T W
authors.initials: TW
authors.lastname: Hamilton
authors.affiliation: Nuffield Orthopaedic Centre, Oxford University Hospitals Trust, Windmill Road, Oxford OX3 7LD, UK.
authors.forename: C
authors.initials: C
authors.lastname: Jenkins
authors.affiliation: NDORMS, University of Oxford, Windmill Road, Oxford OX3 7LD, UK.
authors.forename: S J
authors.initials: SJ
authors.lastname: Mellon
authors.affiliation: Nuffield Orthopaedic Centre, Oxford University Hospitals Trust, Windmill Road, Oxford OX3 7LD, UK.
authors.forename: C A F
authors.initials: CA
authors.lastname: Dodd
authors.affiliation: Nuffield Orthopaedic Centre and NDORMS, University of Oxford, Windmill Road, Oxford OX3 7LD, UK.
authors.forename: D W
authors.initials: DW
authors.lastname: Murray
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D062785:Hemiarthroplasty / Q000379:methods*; D006801:Humans; D007720:Knee Prosthesis; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D020370:Osteoarthritis, Knee / Q000601:surgery; D011446:Prospective Studies; D011475:Prosthesis Failure; D012086:Reoperation / Q000379:methods; D016896:Treatment Outcome
keywords: treatment outcome; unicompartmental knee arthroplasty