Related Experiment Video
Updated: Sep 30, 2026
An Experimental Paradigm for the Prediction of Post-Operative Pain (PPOP)
Published on: January 27, 2010
Perioperative Dynamic Changes and Independent Associations of Pressure Pain Threshold in Trauma Patients: A
Zhijie Yan1,2, Hao Li3, Ziyu Wang3
1Department of Rehabilitation, The Third Affiliated Hospital of Henan Medical University, No. 599 Hualan Avenue Hongqi District, Xinxiang, Henan, China.
Background:
Pressure pain threshold (PPT) is an objective quantitative sensory measure and intermediate biomarker of pain sensitivity. However, the dynamic perioperative alterations and independent clinical determinants of PPT remain insufficiently characterized.
Materials And Methods:
This prospective observational study included 67 adult patients undergoing orthopaedic trauma surgery. Bilateral PPT of injured and uninjured sides was measured at preoperative baseline and postoperative days (POD) 1-3 using a calibrated electronic algometer. Linear mixed-effects models were applied to analyze PPT temporal trends, bilateral differences, and independent associations, with a significance level set at 0.05.
Results:
Continuous bilateral PPT reduction was detected throughout the early postoperative phase. The injured side exhibited significantly lower PPT than the uninjured side on POD 1 (mean difference = -2.43 N, 95% CI: -4.08 to -0.77, p = 0.004), whereas no significant bilateral differences were found preoperatively (p = 0.154), on POD 2 (p = 0.583), or on POD 3 (p = 0.523). No significant time-by-side interaction effects were identified during follow-up. Multivariate analysis demonstrated that age (β = 0.116, p = 0.019) positively correlated with PPT, while female sex (β = -4.715, p = 0.003) and elevated body mass index (BMI) (β = -0.441, p = 0.022) independently decreased PPT values. In contrast, no statistically significant association with PPT was observed for injury type, surgical approach, and anesthesia regimen in the adjusted model. Sensitivity analyses adjusting for morphine equivalent dose, numeric rating scale pain scores, and length of stay supported the robustness of the key POD 1 side-to-side contrast.
Conclusions:
Orthopaedic trauma patients exhibit progressive early-postoperative PPT reduction, with unilateral pain-sensitivity alterations peaking on POD 1. Subsequent bilateral PPT decline may be compatible with broader postoperative changes in pressure pain sensitivity, but mechanistic sensitization cannot be inferred from PPT alone. Independent associations with perioperative PPT were identified for age, sex, and BMI in the adjusted model.
Level Of Evidence:
Level III, prognostic study.
Trial Registration:
Chinese Clinical Trial Registry: ChiCTR2500103937.
