title: Comparative outcomes of total hip and knee arthroplasty: a prospective cohort study.
abstract: OBJECTIVE
  The comparative outcome of primary hip and knee arthroplasty is not well understood. This study aimed to investigate the outcome and satisfaction of these procedures and determine predictive models for 1 year patient outcome with a view to informing surgical management and patient expectations.
  
  
  METHODS
  Prospective cohort study of all primary hip and knee arthroplasty procedures performed at the Royal Infirmary of Edinburgh between January 2006 and November 2008. General health (SF-12) and joint specific function (Oxford Score) was assessed pre-operatively and at 6 and 12 months post-operatively. Patient satisfaction was assessed at 12 months.
  
  
  RESULTS
  1410 total hip arthroplasty (THA) and 1244 total knee arthroplasty (TKA) procedures were assessed. Oxford Score improved by 4.9 points more in THA patients than in TKA patients. SF-12 physical scores were on average 2.7 points greater in the THA patients at one year. Satisfaction was also greater (91%) following THA compared with TKA (81%). Regression modelling was not able to predict individual patient outcome; however, mean pre-operative Oxford Scores were found to be strong predictors of mean post-operative Oxford Scores for each procedure. Age, gender and pre-operative general health scores did not influence these models.
  
  
  CONCLUSIONS
  Both THA and TKA confer substantial improvement in patient outcome; however, greater joint specific, general health and satisfaction scores are reported following THA. This difference is physical in nature. Regression models are presented that can be applied to predict mean hip/knee arthroplasty outcome based on preoperative values.
authors: Department of Orthopaedics and Trauma, University of Edinburgh and Royal Infirmary of Edinburgh, Edinburgh, UK. d.f.hamilton@ed.ac.uk
authors: David
authors: D
authors: Hamilton
authors: G Robin
authors: GR
authors: Henderson
authors: Paul
authors: P
authors: Gaston
authors: Deborah
authors: D
authors: MacDonald
authors: Colin
authors: C
authors: Howie
authors: A Hamish R W
authors: AH
authors: Simpson
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000379:methods / Q000534:rehabilitation*; D019645:Arthroplasty, Replacement, Knee / Q000379:methods / Q000534:rehabilitation*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011446:Prospective Studies; D011788:Quality of Life; D020127:Recovery of Function; D012044:Regression Analysis; D012606:Scotland; D012720:Severity of Illness Index; D016896:Treatment Outcome