title: Is pain and dissatisfaction after TKA related to early-grade preoperative osteoarthritis?
abstract: BACKGROUND
  There is growing evidence to suggest many patients experience pain and dissatisfaction after TKA. The relationship between preoperative osteoarthritis (OA) severity and postoperative pain and dissatisfaction after TKA has not been established.
  
  
  OBJECTIVE
  We explored the relationship between early-grade preoperative OA with pain and dissatisfaction after TKA by (1) determining the incidence of early-grade preoperative OA in painful TKAs with no other identifiable abnormality; and (2) comparing this incidence with the incidence of early-grade OA in three other cohorts of patients undergoing TKA.
  
  
  METHODS
  We evaluated all (n = 49) painful TKAs in a 1-year period that had no evidence of loosening, instability, malalignment, infection, or extensor mechanism dysfunction and classified the degree of preoperative OA according to the scale of Kellgren and Lawrence. For comparison, we identified three other cohorts of TKAs from the same center and classified their preoperative grade of OA: Group B (n = 100) was a consecutive series of primary TKAs performed for OA during the same year; Group C (n = 80) were asymptomatic TKAs from 1 to 4 years postoperatively; and Group D (n = 80) were TKAs with some degree of pain at 1 to 4 years postoperatively.
  
  
  RESULTS
  Patients in Group A had a higher incidence of early-grade OA is preoperatively (49%) compared with any of the comparison groups: Group B, 5%; Group C, 6%; and Group D, 10%.
  
  
  CONCLUSIONS
  A high percentage of patients referred for unexplained pain after TKA had early-grade osteoarthritis preoperatively. Patients undergoing TKA for less than Grade 3 or 4 OA should be informed that they may be at higher risk for persistent pain and dissatisfaction.
authors.affiliation: Department of Orthopedic Surgery, New England Musculoskeletal Institute, University of Connecticut Health Center, Farmington, CT, USA. polkowski@uchc.edu
authors.forename: Gregory G
authors.initials: GG
authors.lastname: Polkowski
authors.forename: Erin L
authors.initials: EL
authors.lastname: Ruh
authors.forename: Toby N
authors.initials: TN
authors.lastname: Barrack
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Nunley
authors.forename: Robert L
authors.initials: RL
authors.lastname: Barrack
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D017060:Patient Satisfaction; D011859:Radiography; D012720:Severity of Illness Index; D016896:Treatment Outcome