title: Pressure Pain Threshold as a Predictor of Acute Postoperative Pain Following Total Joint Arthroplasty.
abstract: OBJECTIVE
  Acute pain in the postoperative period after total joint arthroplasty (TJA) has a significant effect on early rehabilitation, hospital length of stay, and the development of chronic pain. Consequently, efforts have been made to predict the occurrence of postoperative pain using preoperative and intraoperative factors. In this study, we tested the usefulness of preoperative pressure pain threshold (PPT) values in the prediction of three outcomes for patients who underwent TJA: visual analog scale pain scores, hospital length of stay, and opioid consumption.
  
  
  METHODS
  Using a digital pressure algometer, we measured the preoperative PPT in 41 patients expected to undergo TJA at three different body sites: the first web space of the hand, the operative joint, and the contralateral joint. We correlated each PPT separately with postoperative visual analog scale pain scores, hospital length of stay, and opioid consumption.
  
  
  RESULTS
  No significant correlation was found between preoperative PPT and the three postoperative outcomes. This finding held true when patients were subdivided by surgery type (total knee arthroplasty vs. total hip arthroplasty). There was no significant difference in PPT between the three body testing sites.
  
  
  CONCLUSIONS
  This study failed to prove the usefulness of PPT in the prediction of acute postoperative pain, pain medication consumption, and length of stay. The pressure algometer has previously found a place in the assessment of pain in a variety of clinical settings, but its utility has not yet been demonstrated in patients undergoing TJA.
authors.affiliation: Department of Orthopaedic Surgery, University of California, Irvine School of Medicine, Irvine, CA.
authors.forename: Brandon A
authors.initials: BA
authors.lastname: Haghverdian
authors.affiliation: Department of Orthopaedic Surgery, University of California, Irvine School of Medicine, Irvine, CA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Wright
authors.affiliation: Department of Orthopaedic Surgery, University of California, Irvine School of Medicine, Irvine, CA.
authors.forename: Ran
authors.initials: R
authors.lastname: Schwarzkopf
mesh_terms: D000701:Analgesics, Opioid; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D006801:Humans; D007902:Length of Stay; D017288:Pain Threshold; D010149:Postoperative Pain
chemical_list: D000701:Analgesics, Opioid