title: Women recover faster than men after standard knee arthroplasty.
abstract: BACKGROUND
  Specific anatomic differences are believed to account for gender-specific function and health-related quality of life after TKA. However, there are conflicting data in the literature regarding these gender-specific outcomes, especially as woman appear to have surgery later in the course of the disease compared with men.
  
  
  OBJECTIVE
  We asked whether (1) women had worse knee function and health-related quality of life after TKA compared with men, (2) lower improvements in scores, and (3) slower recovery after surgery.
  
  
  METHODS
  Using a cohort study design, we retrospectively analyzed prospectively collected data from three multicenter randomized controlled trials evaluating rehabilitation measures after standard unisex knee arthroplasty in 494 patients (141 men and 353 women). The primary outcome was self-reported physical function as measured by the WOMAC at 3, 6, 12, and 24 months after surgery. Secondary outcomes included the pain and stiffness scales of the WOMAC and the physical and mental component summaries of the SF-36. At the time of surgery, the women were on average older (70.8 versus 67.8 years), had lower mean physical function (55 versus 47), higher mean pain scores (54 versus 48), and greater stiffness (54 versus 46) as measured by the WOMAC.
  
  
  RESULTS
  At the 3-, 6-, 12-, and 24-month followups, men and women had similar WOMAC scores. Improvements were greater for women compared with men for WOMAC function and pain subscale scores at the 3-month (function, 28 versus 23; pain, 32 versus 25) and 6-month followups (function, 32 versus 27; pain, 36 versus 31). At the 12- and 24-month followups we noted no differences in improvement between men and women.
  
  
  CONCLUSIONS
  Although women had greater functional limitations at the time of surgery than men, they recover faster early after standard TKA although function is similar at 12 and 24 months. Women also had greater improvement of WOMAC scores after standard TKA than men.
  
  
  METHODS
  Level II, prognostic study. See the guidelines for authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedic Surgery, University of Schleswig-Holstein Medical Center, Kiel Campus, Michaelisstr 1, 24105 Kiel, Germany. liebs@liebs.eu
authors.forename: Thoralf R
authors.initials: TR
authors.lastname: Liebs
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Herzberg
authors.forename: Annette Maria
authors.initials: AM
authors.lastname: Roth-Kroeger
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Rüther
authors.forename: Joachim
authors.initials: J
authors.lastname: Hassenpflug
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects; D004185:Disability Evaluation; D005260:Female; D005858:Germany; D054624:Health Status Disparities; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D010147:Pain Measurement; D010149:Postoperative Pain / Q000209:etiology; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D020127:Recovery of Function; D012044:Regression Analysis; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome