title: Distinguishing problematic from nonproblematic postsurgical pain: a pain trajectory analysis after total knee arthroplasty.
abstract: The goal of this study was to follow a cohort of patients undergoing total knee arthroplasty over time to: (1) identify and describe the various pain trajectories beginning preoperatively and for up to 12 months after surgery, (2) identify baseline predictors of trajectory group membership, and (3) identify trajectory groups associated with poor psychosocial outcomes 12 months after surgery. One hundred seventy-three participants (female = 85 [49%]; mean age [years] = 62.9, SD = 6.8) completed pain and psychological questionnaires and functional performance tests preoperatively and 4 days, 6 weeks, and 3 and 12 months after total knee arthroplasty. Using growth mixture modeling, results showed that a 4-group model, with a quadratic slope and baseline pain data predicting trajectory group membership, best fit the data (Akaike information criterion = 2772.27). The first 3 pain trajectories represent various rates of recovery ending with relatively low levels of pain 12 months after surgery. Group 4, the constant high pain group, comprises patients who have a neutral or positive pain slope and do not show improvement in their pain experience over the first year after surgery. This model suggests that preoperative pain levels are predictive of pain trajectory group membership and moderate preoperative pain, as opposed to low or high pain, is a risk factor for a neutral or positive pain trajectory postoperatively. Consistent with previous studies, these results show that postoperative pain is not a homogeneous condition and point to the importance of examining intraindividual pain fluctuations as they relate to pain interventions and prevention strategies.
authors.affiliation: Department of Anesthesia, Faculty of Medicine, University of Toronto, Toronto, ON, Canada Department of Psychology, Faculty of Health, York University, Toronto, ON, Canada.
authors.forename: M Gabrielle
authors.initials: MG
authors.lastname: Pagé
authors.forename: Joel
authors.initials: J
authors.lastname: Katz
authors.forename: E Manolo
authors.initials: EM
authors.lastname: Romero Escobar
authors.forename: Noga
authors.initials: N
authors.lastname: Lutzky-Cohen
authors.forename: Kathryn
authors.initials: K
authors.lastname: Curtis
authors.forename: Samantha
authors.initials: S
authors.lastname: Fuss
authors.forename: Hance A
authors.initials: HA
authors.lastname: Clarke
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000175:diagnosis / Q000209:etiology; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis* / Q000209:etiology* / Q000523:psychology; D011569:Psychiatric Status Rating Scales; D016059:Range of Motion, Articular; D011795:Surveys and Questionnaires; D016138:Walking; D055815:Young Adult