preoperative temporal summation is associated with impaired recovery following hip arthroscopy for femoroacetabular impingement syndrome

Objectives: chronic pain is a risk factor for worse outcomes following hip arthroscopy for femoroacetabular impingement syndrome (fais). pain sensitization involves the central nervous system perceiving previously innocuous stimuli as noxious. temporal summation can provide a surrogate measure of sensitization, and may be a clinical tool to identify patients at a higher risk for poor post-hip arthroscopy outcomes. therefore, we aimed to 1) identify the prevalence of temporal summation in patients undergoing hip arthroscopy for fais, 2) determine if there a difference in postoperative improvement between individuals with and without preoperative temporal summation, and 3) examine preoperative predictors of poor postoperative recovery.methods: 51 participants undergoing hip arthroscopy for fais underwent preoperative temporal summation testing. three months postoperatively, 38 participants completed the 12-item international hip outcome tool (ihot-12) and reported their overall symptomatic improvement (0% to 100%, with 100% being normal). participants were categorized on the presence (d numeric pain rating scale; nprs ³ 2) or absence (d nprs < 2) of temporal summation. a mann-whitney u test was used to determine the difference in improvement between groups (temporal summation: ts, no temporal summation nts), and a linear regression was used to explore predictors of improvement.results: 23 (45.1%) of 51 participants displayed preoperative temporal summation. in participants with postoperative data, those with temporal summation reported less improvement than those without (ts: 62.8% ± 29.7%; nts: 82.7% ± 13.9%; p = 0.01; cohen’s d = -0.86). temporal summation (beta = -0.48; 95% ci -36.6, -8.7) and mental health disorder (beta = -0.30; 95% ci -28.0, -0.48) predicted 28.1% of the variance in postoperative improvement (p = 0.002).conclusion: the presence of preoperative temporal summation is common and related to worse postoperative recovery after hip arthroscopy for fais.        level of evidence: iv