Associations of varus thrust and alignment with pain in knee osteoarthritis

Arthritis & Rheumatism, 04/25/2012

Lo GH et al. – In those with knee osteoarthritis (OA), varus thrust and possibly varus static alignment, were associated with pain, specifically during weight–bearing activities. Treatment of varus thrust (e.g. via bracing or gait modification) may lead to improvement of symptoms.

Methods

  • This was a cross–sectional study of participants from a randomized controlled trial of vitamin D for knee OA.
  • Participants were video recorded walking and scored for presence of varus thrust.
  • Standard PA knee X–rays were measured for static alignment.
  • Pain questions from the Western Ontario McMasters Osteoarthritis (WOMAC) questionnaire assessed symptoms.
  • The authors calculated means for total WOMAC pain by varus thrust and varus alignment (i.e. corrected anatomic alignment < 178°).
  • They performed ordinal logistic regressions; outcomes: individual WOMAC pain questions; predictors: varus thrust and varus alignment.

Results

  • There were 82 participants, mean age 65.1 (±8.5), mean body mass index 30.2 (±5.4), and 60% female.
  • Total WOMAC pain was 6.3 versus 3.9, p = 0.007 in those with versus without definite varus thrust.
  • For varus alignment, total WOMAC pain was 5.2 versus 4.2, p = 0.30.
  • Odds ratios for pain with walking and standing were 5.5 (95%CI 2.0 – 15.1) and 6.0 (95%CI 2.2 – 16.2) in those with versus without definite varus thrust.
  • There were no significant associations between varus alignment and individual WOMAC pain questions.
  • Sensitivity analyses suggested a more stringent definition of varus might have been associated with walking and standing pain.

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