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:
