The relationship between prescribed pre-operative knee-extensor exercise dosage and effect on knee-extensor strength prior to and following total knee arthroplasty: a systematic review and meta-regression analysis of randomized controlled trials

Osteoarthritis Cartilage. 2020 Nov;28(11):1412-1426. doi: 10.1016/j.joca.2020.08.011. Epub 2020 Sep 2.


Objective: The aim of this systematic review was to evaluate the relationship between prescribed knee-extensor strength exercise dosage in pre-operative exercise intervention and the effect on knee-extensor muscle strength prior to and following TKA. Additional meta-analyses report the effect of pre-habilitation on outcomes prior to and following TKA.

Design: A systematic literature search was performed including RCT's evaluating the effect of pre-operative exercise prior to and following TKA. Meta-regression analysis was performed to evaluate the dose-response relationship between prescribed exercise dose and the pooled effect, measured as standardized mean difference (SMD). The prescribed exercise dose was quantified using a formula accounting for as many exercise descriptors as possible. Risk of bias in the included trials was assessed using the Cochrane Risk of Bias Tool.

Results: Twelve trials with 616 patients were included. Meta-regression analysis showed no relationship between prescribed pre-operative knee-extensor exercise dosage and change in knee-extensor strength neither prior to (slope 0.0005 [95%CI -0.007 to 0.008]) or 3 months following TKA (slope 0.0014 [95%CI -0.006 to 0.009]). Prior to TKA, a moderate effect favoring pre-operative exercise for increase in knee-extensor strength was found (SMD 0.50 [95%CI 0.12 to 0.88]), but not at 3 months following TKA (SMD -0.01 [95%CI -0.45 to 0.43]). Risk of bias was generally assessed as unclear.

Conclusion: Meta-regression analysis of existing trials suggests no relationship between the prescribed pre-operative knee-extensor exercise dosage and the change in knee-extensor strength observed prior to and following TKA. Pre-operative exercise including knee-extensor muscle strength exercise increased knee-extensor strength moderately prior to but not 3 months following TKA.

Protocol registration: PROSPERO ID (CRD42018076308) (

Keywords: Dose-response; Exercise therapy; Knee osteoarthritis; Knee-extensor muscle strength; Total knee arthroplasty.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Systematic Review

MeSH terms

  • Aged
  • Arthroplasty, Replacement, Knee / methods*
  • Female
  • Humans
  • Knee
  • Male
  • Middle Aged
  • Osteoarthritis, Knee / physiopathology
  • Osteoarthritis, Knee / rehabilitation*
  • Osteoarthritis, Knee / surgery*
  • Preoperative Exercise*
  • Quadriceps Muscle / physiopathology
  • Randomized Controlled Trials as Topic
  • Resistance Training / methods*