title: Medical and psychological comorbidity predicts poor pain outcomes after total knee arthroplasty.
abstract: OBJECTIVE
  To study comorbidity correlates of moderate to severe pain after total knee arthroplasty (TKA).
  
  
  METHODS
  We analysed prospectively collected Total Joint Registry data to examine whether medical (heart disease, peripheral vascular disease, renal disease, chronic obstructive pulmonary disease, diabetes and CTD) and psychological (anxiety and depression) comorbidity is associated with moderate to severe pain after primary or revision TKA. Multivariable-adjusted logistic regression simultaneously adjusted for all comorbidities, age, sex, BMI, underlying diagnosis, American Society of Anesthesiologist (ASA) class, distance from medical centre and implant fixation (only for primary TKA) was used to analyse primary and revision TKA separately.
  
  
  RESULTS
  The primary TKA cohort consisted of 7139 and 4234 TKAs (response rates 65% and 57%) and the revision TKA cohort consisted of 1533 and 881 TKAs at 2 and 5 years (response rates 57% and 48%), respectively. In the primary TKA cohort, anxiety was associated with 1.4 higher odds (95% CI 1.0, 2.0) of moderate to severe index knee pain at 2 years; at 5 years, heart disease (OR 1.7; 95% CI 1.1, 2.6), depression (OR 1.7; 95% CI 1.1, 2.5) and anxiety (OR 1.9; 95% CI 1.2, 3.1) were significantly associated with moderate to severe pain. For revision TKA, CTD (OR 0.5; 95% CI 0.2, 0.9) and depression (OR 1.8; 95% CI 1.1, 3.1) were significantly associated with moderate to severe pain.
  
  
  CONCLUSIONS
  This study identified medical and psychological comorbidity risk factors for moderate to severe pain after primary and revision TKA. This information can be used to provide realistic outcome expectations for patients before undergoing primary or revision TKA.
authors: Medicine Service and Center for Surgical Medical Acute Care Research and Transitions, Birmingham VA Medical Center, AL, USA. jasvinder.md@gmail.com
authors: Jasvinder A
authors: JA
authors: Singh
authors: David G
authors: DG
authors: Lewallen
mesh_terms: D000223:Adaptation, Psychological; D000368:Aged; D000369:Aged, 80 and over; D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods*; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006801:Humans; D055809:Illness Behavior; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000453:epidemiology*; D016017:Odds Ratio; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000601:surgery*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011859:Radiography; D012042:Registries; D012086:Reoperation / Q000706:statistics & numerical data; D018570:Risk Assessment; D013997:Time Factors; D016896:Treatment Outcome