title: Association Between Exercise Therapy Dose and Functional Improvements in the Early Postoperative Phase After Hip and Knee Arthroplasty: An Observational Study.
abstract: OBJECTIVE
  To determine whether intensity and duration of standard exercise therapy are associated with changes in function after total hip arthroplasty (THA) and total knee arthroplasty (TKA).
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Orthopedic inpatient rehabilitation center.
  
  
  METHODS
  A total of 123 patients 2 weeks after THA (n = 58; age, 62.5 ± 10.4 years) and TKA (n = 65; age, 66.6 ± 7.6 years).
  
  
  METHODS
  Standard rehabilitation (hands-on physiotherapy, group exercise therapy, strength training, cycle ergometer therapy, continuous passive motion therapy, and water exercise therapy).
  
  
  METHODS
  The Western Ontario and McMaster Universities Arthritis Index (WOMAC) and hip and knee range of motion (ROM) were assessed before and after inpatient rehabilitation.
  
  
  RESULTS
  The individual rehabilitation period varied between 12-25 days and included 48.1 ± 12.5 (THA) or 41.9 ± 9.7 (TKA) exercise interventions with intensities between 9.6 and 14.0 points on the Borg Rate of Perceived Exertion Scale. WOMAC pain (P < .001), stiffness (P < .001), and function (P < .001), as well as hip (P < .001) and knee (P < .001) ROM, improved significantly in THA and TKA patients. Analysis of covariance showed that these changes could not be explained by the total duration or mean intensity of exercise therapy.
  
  
  CONCLUSIONS
  The findings show a low dose-response relationship between early postoperative exercise therapy and the improvements in function or ROM after THA and TKA. Although the findings raise questions about the efficacy of existing rehabilitation programs, the small sample size, single setting, and geographic differences in postoperative treatment standards limit the generalizability of findings.
authors.affiliation: Institute of Sport Science, University of Jena, Jena, Germany.
authors.forename: Astrid
authors.initials: A
authors.lastname: Zech
authors.affiliation: Department of Sports Science and Sports, University of Erlangen-Nuremberg, Erlangen and Nuremberg, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Hendrich
authors.affiliation: Department of Sports Science and Sports, University of Erlangen-Nuremberg, Erlangen and Nuremberg, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Pfeifer
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000534:rehabilitation*; D019645:Arthroplasty, Replacement, Knee / Q000534:rehabilitation*; D015331:Cohort Studies; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000534:rehabilitation* / Q000601:surgery*; D016059:Range of Motion, Articular; D020127:Recovery of Function; D057566:Self Report; D013997:Time Factors; D016896:Treatment Outcome