The influence of surgical factors on dislocation of the meniscal bearing after Oxford medial unicompartmental knee replacement: A case-control study

S. Y. Lee, Ji Hoon Bae, Jae Gyoon Kim, Ki-Mo Jang, Won Yong Shon, K. W. Kim, H. C. Lim

Research output: Contribution to journalArticle


The aim of this study was to evaluate the risk factors for dislocation of the bearing after a mobile-bearing Oxford medial unicompartmental knee replacement (UKR) and to test the hypothesis that surgical factors, as measured from post-operative radiographs, are associated with its dislocation From a total of 480 UKRs performed between 2001 and 2012, in 391 patients with a mean age of 66.5 years (45 to 82) (316 female, 75 male), we identified 17 UKRs where bearing dislocation occurred. The post-operative radiological measurements of the 17 UKRs and 51 matched controls were analysed using conditional logistic regression analysis. The postoperative radiological measurements included post-operative change in limb alignment, the position of the femoral and tibial components, the resection depth of the proximal tibia, and the femoral component-posterior condyle classification. We concluded that a post-operative decrease in the posterior tibial slope relative to the pre-operative value was the only significant determinant of dislocation of the bearing after medial Oxford UKR (odds ratio 1.881; 95% confidence interval 1.272 to 2.779). A postoperative posterior tibial slope < 8.45° and a difference between the pre-operative and postoperative posterior tibial slope of > 2.19° may increase the risk of dislocation.

Original languageEnglish
Pages (from-to)914-922
Number of pages9
JournalBone and Joint Journal
Volume96 B
Issue number7
Publication statusPublished - 2014 Jan 1


ASJC Scopus subject areas

  • Surgery
  • Orthopedics and Sports Medicine

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