title: Reason for revision influences early patient outcomes after aseptic knee revision.
abstract: BACKGROUND
  Revision TKA less consistently produces improvements in clinical function and quality of life when compared with primary TKA. The reasons for this difference are unclear.
  
  
  OBJECTIVE
  We determined differences in patient-reported outcomes and rates of satisfaction between primary and revision TKAs, and determine whether the reason for revision influences patient-reported outcomes after revision TKA.
  
  
  METHODS
  We retrospectively analyzed prospectively collected patient-reported outcome measures (PROMs) for 24,190 patients (23,393 TKAs; 797 aseptic revision TKAs). We compared patient-reported outcomes using the Oxford Knee Score (OKS), EuroQol (EQ-5D), and patient satisfaction between primary TKA and revision TKA, and for subsets of the revision TKA cohort. The followup data were collected between 6 and 12 months (7 months average) postoperatively.
  
  
  RESULTS
  Improvements in the OKS (10) and EQ-5D (0.231) were smaller after revision when compared with primary TKA (OKS, 15; EQ-5D, 0.303). Patients who had revision TKA were less satisfied (66% versus 83%). Revisions for aseptic loosening or lysis were associated with the best patient outcomes (OKS improvement = 11; EQ-5D improvement = 0.232; satisfaction = 72%). Revisions for stiffness had the worst results (OKS improvement = 6; EQ-5D improvement = 0.176; satisfaction = 47%).
  
  
  CONCLUSIONS
  The early improvements in knee function and general health after revision TKA are only 69% to 76% of those observed for primary TKA. Levels of patient-reported knee function, general health, and satisfaction after revision are varied and related to the reason for revision. Even the best revision group does not approach the levels of function and satisfaction observed after primary TKA at a mean of 7 months postoperatively. Longer-term followup would be required to determine whether conclusions from these early data will need to be modified.
  
  
  METHODS
  Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Institute of Cellular Medicine, University of Newcastle, Newcastle upon Tyne, England. drpnbaker@hotmail.com
authors.forename: Paul
authors.initials: P
authors.lastname: Baker
authors.forename: Paul
authors.initials: P
authors.lastname: Cowling
authors.forename: Steven
authors.initials: S
authors.lastname: Kurtz
authors.forename: Simon
authors.initials: S
authors.lastname: Jameson
authors.forename: Paul
authors.initials: P
authors.lastname: Gregg
authors.forename: David
authors.initials: D
authors.lastname: Deehan
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D004185:Disability Evaluation; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data; D010146:Pain; D017060:Patient Satisfaction / Q000706:statistics & numerical data; D016459:Prosthesis-Related Infections / Q000601:surgery*; D011788:Quality of Life; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012720:Severity of Illness Index