Restoring the anatomical tibial slope and limb axis may maximise post-operative flexion in posterior-stabilised total knee replacements

G. Singh, J. H. Tan, B. Y. Sng, F. Awiszus, C. H. Lohmann, S. S. Nathan

Abstract

The optimal management of the tibial slope in achieving a high flexion angle in posterior-stabilised (PS) total knee replacement (TKR) is not well understood, and most studies evaluating the posterior tibial slope have been conducted on cruciate-retaining TKRs. We analysed pre- and post-operative tibial slope differences, pre- and post-operative coronal knee alignment and post-operative maximum flexion angle in 167 patients undergoing 209 TKRs. The mean pre-operative posterior tibial slope was 8.6° (1.3° to 17°) and post-operatively it was 8.0° (0.1° to 16.7°). Multiple linear regression analysis showed that the absolute difference between pre- and post-operative tibial slope (p < 0.001), post-operative coronal alignment (p = 0.02) and pre-operative range of movement (p < 0.001) predicted post-operative flexion. The variance of change in tibial slope became larger as the post-operative maximum flexion angle decreased. The odds ratio of having a post-operative flexion angle < 100° was 17.6 if the slope change was > 2°. Our data suggest that recreation of the anatomical tibial slope appears to improve maximum flexion after posterior-stabilised TKR, provided coronal alignment has been restored.

Cite this article: Bone Joint J 2013;95-B:1354–8.

Footnotes

  • No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.

    This article was primary edited by D. Rowley and first-proof edited by G. Scott.

  • Received December 16, 2012.
  • Accepted June 3, 2013.
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