title: Preoperative physical activity level has no relationship to the degree of recovery one year after primary total hip or knee arthroplasty: a cohort study.
abstract: BACKGROUND
  When it comes to prevalidation, it is assumed that a higher preoperative level of physical activity leads to better postoperative recovery. However current literature is inconclusive about the effect of prevalidation on functional recovery of patients with primary osteoarthritis (OA) who underwent a THA or TKA. Therefore the aim of this study is to analyse one of the major assumptions underlying the potential effectiveness of prevalidation namely the relationship between preoperative physical activity level and postoperative recovery one year after THA or TKA in a group of 658 OA patients.
  
  
  RESULTS
  From 2006 to 2012, 1061 patients underwent a primary THA or TKA at University Medical Center Groningen. Preoperative and one-year postoperative patients filled in the SQUASH questionnaire to get an impression of their physical activity level, and the WOMAC questionnaire to obtain insight into degree of recovery. Missing data were multiply imputed. No relationship was found between the preoperative total (B-coefficient = 0.03, CI95%  =  -0.033-0.093) and leisure-time physical activity level (B-coefficient = 0.042, CI95%  =  -0.009-0.093) neither for preoperative compliance with the Dutch Recommendation for Health-Enhancing Physical Activity (B-coefficient = 0.002, CI95%  =  -0.053-0.057), and the degree of recovery one year after surgery.
  
  
  CONCLUSIONS
  The preoperative physical activity level had no relation with the degree of recovery one year after THA or TKA. The results do not support one of the major assumptions behind prevalidation, which assumes that a higher preoperative physical activity level will lead to a better recovery after THA or TKA.
authors.affiliation: Department of Orthopaedics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Sietske
authors.initials: S
authors.lastname: Poortinga
authors.affiliation: Department of Orthopaedics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Inge
authors.initials: I
authors.lastname: van den Akker-Scheek
authors.affiliation: Department of Orthopaedics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Sjoerd K
authors.initials: SK
authors.lastname: Bulstra
authors.affiliation: Department of Health Sciences, Community and Occupational Sciences, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Roy E
authors.initials: RE
authors.lastname: Stewart
authors.affiliation: Department of Orthopaedics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Martin
authors.initials: M
authors.lastname: Stevens
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D019645:Arthroplasty, Replacement, Knee; D015331:Cohort Studies; D003710:Demography; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D009043:Motor Activity; D011300:Preoperative Care; D020127:Recovery of Function; D011795:Surveys and Questionnaires