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. 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 ۱) identify the prevalence of temporal summation in patients undergoing hip arthroscopy for FAIS, ۲) determine if there a difference in postoperative improvement between individuals with and without preoperative temporal summation, and ۳) examine preoperative predictors of poor postoperative recovery.Methods: ۵۱ participants undergoing hip arthroscopy for FAIS underwent preoperative temporal summation testing. Three months postoperatively, ۳۸ participants completed the ۱۲-item International Hip Outcome Tool (iHOT-۱۲) and reported their overall symptomatic improvement (۰% to ۱۰۰%, with ۱۰۰% being normal). Participants were categorized on the presence (D Numeric Pain Rating Scale; NPRS ³ ۲) or absence (D NPRS < ۲) 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: ۲۳ (۴۵.۱%) of ۵۱ participants displayed preoperative temporal summation. In participants with postoperative data, those with temporal summation reported less improvement than those without (TS: ۶۲.۸% ± ۲۹.۷%; NTS: ۸۲.۷% ± ۱۳.۹%; p = ۰.۰۱; Cohen’s d = -۰.۸۶). Temporal summation (Beta = -۰.۴۸; ۹۵% CI -۳۶.۶, -۸.۷) and mental health disorder (Beta = -۰.۳۰; ۹۵% CI -۲۸.۰, -۰.۴۸) predicted ۲۸.۱% of the variance in postoperative improvement (p = ۰.۰۰۲).Conclusion: The presence of preoperative temporal summation is common and related to worse postoperative recovery after hip arthroscopy for FAIS.        Level of evidence: IV

Keywords:

hip preservation , pre-arthritic hip , Quantitative sensory testing