title: Acute pain trajectories and the persistence of post-surgical pain: a longitudinal study after total hip arthroplasty.
abstract: The aim of this study was to explore acute movement-evoked postoperative pain intensity trajectories over the first 5 days after total hip arthroplasty (THA) and to examine how these pain trajectories are associated with pain-related outcomes 6 weeks and 6 months later.
  
  
  
  A total of 150 adult patients [72 women (48.0 %); mean age 60.0 ± 9.2 (standard deviation) years] completed pain questionnaires preoperatively, several times daily postoperatively until hospital discharge, and 6 weeks and 6 months after surgery.
  
  
  
  Results showed that the best model had four different acute postoperative pain trajectories and a significant quadratic term. The trajectories varied in terms of initial pain intensity levels and rates of decline/increase in pain over the first 4 postoperative days. Significant predictors of pain trajectory membership were preoperative pain disability and anxiety as well as cumulative morphine consumption 24 h following surgery. Pain trajectories were significantly associated with levels of pain intensity and anxiety at 6 weeks but not at 6 months postoperatively.
  
  
  
  This study showed that during the postoperative period patients differed in terms of pain intensity profiles and that these differences were associated with outcomes for up to 6 weeks following surgery. Pain trajectories were not predictive of persistent postoperative pain status at 6 months. Nonetheless, these results highlight the importance of patient heterogeneity in acute postoperative pain and pain-related outcomes months after THA.
authors.affiliation: Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Université de Montréal, Montréal, QC, Canada.
authors.forename: M Gabrielle
authors.initials: MG
authors.lastname: Pagé
authors.affiliation: Department of Anesthesia, Faculty of Medicine, University of Toronto, Toronto, Canada.|Department of Psychology, Faculty of Health, York University, Toronto, ON, Canada.
authors.forename: Joel
authors.initials: J
authors.lastname: Katz
authors.affiliation: Department of Psychology, Faculty of Health, York University, Toronto, ON, Canada.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Curtis
authors.affiliation: Department of Anesthesia, Faculty of Medicine, University of Toronto, Toronto, Canada.
authors.forename: Noga
authors.initials: N
authors.lastname: Lutzky-Cohen
authors.affiliation: Department of Psychology, Faculty of Health, York University, Toronto, ON, Canada.
authors.forename: E Manolo Romero
authors.initials: EM
authors.lastname: Escobar
authors.affiliation: Department of Anesthesia, Faculty of Medicine, University of Toronto, Toronto, Canada. hance.clarke@utoronto.ca.|Department of Anesthesia, Toronto General Hospital, 200 Elizabeth Street, Eaton North 3 EB 317 , Toronto, ON, M5G 2C4, Canada. hance.clarke@utoronto.ca.
authors.forename: Hance A
authors.initials: HA
authors.lastname: Clarke
mesh_terms: D059787:Acute Pain / Q000453:epidemiology*; D000328:Adult; D000368:Aged; D001007:Anxiety / Q000453:epidemiology*; D019644:Arthroplasty, Replacement, Hip; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage; D010147:Pain Measurement; D010149:Postoperative Pain / Q000453:epidemiology*; D011184:Postoperative Period; D011795:Surveys and Questionnaires
chemical_list: D009020:Morphine
keywords: Chronic post-surgical pain; Pain trajectories; Total hip arthroplasty; Transition acute to chronic pain