title: Severe arthritis predicts greater improvements in function following total knee arthroplasty.
abstract: OBJECTIVE
  Although excellent outcomes are routinely reported following total knee replacement, up to 20 % of patients remain dissatisfied. The aim of this study was to determine whether pre-operative radiographic classification was associated with functional outcomes following surgery.
  
  
  METHODS
  A retrospective review of a prospective arthroplasty database identified 256 patients that fulfilled the inclusion criteria over an 18-month period. Baseline demographic data on all patients were collected prospectively. All pre-operative radiographs were assessed using the Kellgren and Lawrence (K&L) classification system. Patients were prospectively assessed using the American Knee Society Score pre-operatively and at 1, 3 and 5 years post-surgery.
  
  
  RESULTS
  An association was found between the pre-operative radiographic severity of arthritis and the pre-operative American Knee Society Knee (AKSK) scores, with worsening radiographic grade corresponding to worsening AKSK scores (p = 0.020). There was an association between K&L classification and improvement in AKSK scores from pre-operative to 1 year (p = 0.003) and 3 years (p = 0.04), with K&L grades 3 and 4 demonstrating the most significant improvements. On multivariate regression analysis, K&L classification was the only significant predictor of improvement in AKSK at 1 year (p = 0.009). No correlation was found between K&L grade and the American Knee Society Functional Scores at any stage.
  
  
  CONCLUSIONS
  The results of this study may help to improve satisfaction rates in total knee replacement by targeting treatment. Patients can be counselled that although radiographic severity of arthritic changes can predict knee-specific functional improvement, the extent of their global functional improvement cannot.
  
  
  METHODS
  IV.
authors.affiliation: Edinburgh Royal Infirmary, Edinburgh, Scotland, UK. oliverstone@doctors.org.uk.
authors.forename: O D
authors.initials: OD
authors.lastname: Stone
authors.affiliation: Edinburgh Royal Infirmary, Edinburgh, Scotland, UK.
authors.forename: A D
authors.initials: AD
authors.lastname: Duckworth
authors.affiliation: Victoria Hospital Kirkcaldy, Fife, Scotland, UK.
authors.forename: D P
authors.initials: DP
authors.lastname: Curran
authors.affiliation: Victoria Hospital Kirkcaldy, Fife, Scotland, UK.
authors.forename: J A
authors.initials: JA
authors.lastname: Ballantyne
authors.affiliation: Victoria Hospital Kirkcaldy, Fife, Scotland, UK.
authors.forename: I J
authors.initials: IJ
authors.lastname: Brenkel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000145:classification / Q000000981:diagnostic imaging* / Q000601:surgery*; D017060:Patient Satisfaction; D011859:Radiography; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome
keywords: Arthritis; Arthroplasty; Grade; Knee; Outcomes