A multivariate statistical ranking of clinical and gait measures before and after total knee replacement

Gait Posture. 2009 Aug;30(2):197-200. doi: 10.1016/j.gaitpost.2009.04.009. Epub 2009 May 22.


The purpose of this study was to assess the use of a multivariate statistical method to rank clinical and gait variables, thus describing a ranking of patient dysfunction prior to and following total knee replacement (TKR) surgery. Twenty end-stage knee osteoarthritis (KOA) subjects scheduled for TKR and 20 healthy controls performed level walking and stair ascent twice: pre- (P1) and 6 months post-surgery (P2). Clinical and gait measures were entered into a principle component analysis (PCA) to determine orthogonal principle components (PCs). The PCs were entered into a discriminant function analysis to determine the best predictors of group membership. The PCA extracted three PCs for both the P1 and P2 data sets. Three orthogonal dimensions were formed: "knee dysfunction", "gait dysfunction", and "stair ascent dysfunction". For P1 the "knee dysfunction" dimension composed of both subjective and objective measures, best discriminated between end-stage knee osteoarthritis patients and controls. For P2, the "stair ascent dysfunction" dimension best discriminated between 6 months post-TKR patients and controls. The results of this study suggest that a multivariate statistical method provides a clinically relevant ranking of patient dysfunction prior to and following TKR. This ranking of dysfunction could serve to identify rehabilitation priorities.

MeSH terms

  • Aged
  • Arthroplasty, Replacement, Knee / rehabilitation*
  • Case-Control Studies
  • Disability Evaluation*
  • Discriminant Analysis
  • Female
  • Gait*
  • Humans
  • Male
  • Middle Aged
  • Models, Biological
  • Multivariate Analysis*
  • Osteoarthritis, Knee / physiopathology
  • Osteoarthritis, Knee / rehabilitation
  • Osteoarthritis, Knee / surgery*
  • Principal Component Analysis