The management of mobile bearing dislocation in the Oxford lateral unicompartmental knee replacement

Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Headington, Oxford, OX3 7LD, UK.
Knee Surgery Sports Traumatology Arthroscopy (Impact Factor: 3.05). 03/2011; 19(12):2023-6. DOI: 10.1007/s00167-011-1446-8
Source: PubMed


This article describes a technique to manage dislocations of mobile bearing lateral unicompartmental knee replacements. When dislocations occur, the bearing usually subluxes medially over the medial wall of the tibial component into the intercondylar notch. By positioning small fragment screws with their heads above the vertical wall, thereby increasing the height of the wall, subsequent dislocations can be prevented. Seven cases treated in this manner are reported, of which one of the seven has redislocated. In the remaining six, their clinical outcomes are comparable to the outcomes of those without dislocations.

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    ABSTRACT: This is a retrospective study comparing the clinical outcomes of mobile vs fixed medial unicompartmental knee replacements. Patients were identified from a prospectively collected database. Demographic data and pre- and postoperative outcomes (Oxford, Western Ontario and McMaster Universities Osteoarthritis Index, Short Form Health Survey-12, and satisfaction) were collected-104 knees (90 patients) with minimum 2-years of follow-up: 37 mobile and 67 fixed-bearing. At baseline, the median age was 60 years (mobile) and 66 (fixed); body mass index was significantly higher (32) for the mobile group than for the fixed (28). At follow-up, the groups differed only in the Oxford score: median 83 (mobile) and 90 (fixed). There is no difference in outcomes between mobile and fixed unicompartmental knee replacements.
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