title: The effects of knee arthroplasty on walking speed: a meta-analysis.
abstract: BACKGROUND
  Patients with knee osteoarthritis patients have problems with walking, and tend to walk slower. An important aim of knee arthroplasty is functional recovery, which should include a post-operative increase in walking speed. Still, there are several problems with measuring walking speed in groups of knee osteoarthritis patients. Nevertheless, test-retest reliability of walking speed measurements is high, and when the same investigators monitor the same subjects, it should be possible to assess the walking speed effects of knee arthroplasty. The present study reports a meta-analysis of these effects.
  
  
  METHODS
  A total of 16 independent pre-post arthroplasty comparisons of walking speed were identified through MEDLINE, Web of Science, and PEDro, in 12 papers, involving 419 patients.
  
  
  RESULTS
  For 0.5-5 months post-operatively, heterogeneity was too large to obtain a valid estimate of the overall effect-size. For 6-12 and 13-60 months post-operatively, heterogeneity was absent, low, or moderate (depending on estimated pre-post correlations). During these periods, subjects walked on average 0.8 standard-deviations faster than pre-operatively, which is a large effect. Meta-regression analysis revealed significant effects of time and time squared, suggesting initial improvement followed by decline.
  
  
  CONCLUSIONS
  This meta-analysis revealed a large effect of arthroplasty on walking speed 6-60 months post-operatively. For the first 0.5-5 months, heterogeneity of effect-sizes precluded a valid estimate of short-term effects. Hence, patients may expect a considerable improvement of their walking speed, which, however, may take several months to occur. Meta-regression analysis suggested a small decline from 13 months post-operatively onwards.
authors.affiliation: Research Institute MOVE, Faculty of Human Movement Sciences, VU University, Amsterdam, The Netherlands.
authors.forename: Hamid
authors.initials: H
authors.lastname: Abbasi-Bafghi
authors.forename: Hamid R
authors.initials: HR
authors.lastname: Fallah-Yakhdani
authors.forename: Onno G
authors.initials: OG
authors.lastname: Meijer
authors.forename: Henrica C W
authors.initials: HC
authors.lastname: de Vet
authors.forename: Sjoerd M
authors.initials: SM
authors.lastname: Bruijn
authors.forename: Li-Yong
authors.initials: LY
authors.lastname: Yang
authors.forename: Dirk L
authors.initials: DL
authors.lastname: Knol
authors.forename: Barend J
authors.initials: BJ
authors.lastname: Van Royen
authors.forename: Jaap H
authors.initials: JH
authors.lastname: van Dieën
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000601:surgery*; D020127:Recovery of Function; D013997:Time Factors; D016896:Treatment Outcome; D016138:Walking