title: The mid-term outcomes of the Oxford Domed Lateral unicompartmental knee replacement.
abstract: Mobile-bearing unicompartmental knee replacements (UKRs) with a flat tibial plateau have not performed well in the lateral compartment, owing to a high dislocation rate. This led to the development of the Domed Lateral Oxford UKR (Domed OUKR) with a biconcave bearing. The aim of this study was to assess the survival and clinical outcomes of the Domed OUKR in a large patient cohort in the medium term. We prospectively evaluated 265 consecutive knees with isolated disease of the lateral compartment and a mean age at surgery of 64 years (32 to 90). At a mean follow-up of four years (sd 2.2, (0.5 to 8.3)) the mean Oxford knee score was 40 out of 48 (sd 7.4). A total of 12 knees (4.5%) [corrected] had re-operations, of which four (1.5%) were for dislocation. All dislocations occurred in the first two years. Two (0.8%) were secondary to significant trauma that resulted in ruptured ligaments, and two (0.8%) were spontaneous. In four patients (1.5%) the UKR was converted to a primary TKR. Survival at eight years, with failure defined as any revision, was 92.1% (95% confidence interval 81.3 to 100). The Domed Lateral OUKR gives good clinical outcomes, low re-operation and revision rates and a low dislocation rate in patients with isolated lateral compartmental disease, in the hands of the designer surgeons.
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences,, Botnar Research Centre, University of Oxford, Windmill Road, Headington, Oxford, OX3 7LD, UK.
authors.forename: J S
authors.initials: JS
authors.lastname: Weston-Simons
authors.forename: H
authors.initials: H
authors.lastname: Pandit
authors.forename: B J L
authors.initials: BJ
authors.lastname: Kendrick
authors.forename: C
authors.initials: C
authors.lastname: Jenkins
authors.forename: K
authors.initials: K
authors.lastname: Barker
authors.forename: C A F
authors.initials: CA
authors.lastname: Dodd
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 / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D062785:Hemiarthroplasty / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D031221:Knee Dislocation / Q000000981:diagnostic imaging / Q000601:surgery; D007719:Knee Joint / Q000000981:diagnostic imaging; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation / Q000379:methods; D016896:Treatment Outcome
keywords: Clinical outcome; Complications; Designer series; Dislocation; Lateral unicompartmental knee replacement; Survival