title: Abnormal quantitative sensory testing is associated with persistent pain one year after TKA.
abstract: BACKGROUND
  Up to 15% of patients report at least moderate persistent pain after TKA. Such pain may be associated with the presence of widespread hyperalgesia and neuropathic-type pain.
  
  
  OBJECTIVE
  We asked if there was a difference among patients who report moderate to severe pain or no pain at least 12 months after TKA regarding (1) pressure pain threshold, (2) thermal (cold/heat) pain and detection thresholds, and (3) self-reported neuropathic pain.
  
  
  METHODS
  Fifty-three volunteers were recruited from patients reporting no pain or moderate to severe pain, according to the Knee Society Score©. Differences between the moderate-to-severe and no-pain groups regarding pressure pain, heat and cold thresholds, and self-reported neuropathic-type pain were analyzed using independent t-tests.
  
  
  RESULTS
  Patients in the moderate-to-severe pain group exhibited reduced pressure pain threshold in the knee with the TKA (p=0.025) and at the elbow (p=0.002). This group also showed greater pain sensitivity to cold at the knee (p=0.008) and elbow (p=0.010), and increased heat pain sensitivity at the elbow (p=0.032). Cold and heat detection thresholds were impaired in this group at the elbow (cold, p=0.034; heat, p=0.010), although only heat detection was impaired at the knee (p=0.009). The moderate-to-severe pain group also reported more neuropathic-type pain (p=0.001).
  
  
  CONCLUSIONS
  Persistent pain after TKA was associated with widespread pressure, cold hyperalgesia, and greater neuropathic-type pain.
  
  
  METHODS
  Level III, prognostic study.
authors.affiliation: School of Physiotherapy and Exercise Science, Curtin University, Kent Street, Bentley, Perth, WA, 6102, Australia.
authors.forename: Anthony
authors.initials: A
authors.lastname: Wright
authors.forename: Penny
authors.initials: P
authors.lastname: Moss
authors.forename: Karen
authors.initials: K
authors.lastname: Sloan
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Beaver
authors.forename: Jarle B
authors.initials: JB
authors.lastname: Pedersen
authors.forename: Gerard
authors.initials: G
authors.lastname: Vehof
authors.forename: Henrik
authors.initials: H
authors.lastname: Borge
authors.forename: Luca
authors.initials: L
authors.lastname: Maestroni
authors.forename: Philip
authors.initials: P
authors.lastname: Cheong
mesh_terms: D000368:Aged; D018771:Arthralgia / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D003080:Cold Temperature; D003430:Cross-Sectional Studies; D005260:Female; D006358:Hot Temperature; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D010147:Pain Measurement; D058748:Pain Perception; D017288:Pain Threshold; D010149:Postoperative Pain / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011312:Pressure; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013697:Thermosensing; D013997:Time Factors; D016896:Treatment Outcome