Poster 186: The Utility of Preoperative Hip Injection Response as a Predictor of 2-Year Postoperative Outcomes Following Hip Arthroscopy for Femoroacetabular Impingement

Abstract

Objectives: The objective of this study is to determine whether response to preoperative lidocaine or corticosteroid intra-articular hip injections can predict 2-year postoperative outcomes in patients undergoing arthroscopic management of femoroacetabular impingement syndrome (FAIS). Methods: We performed a retrospective analysis of a prospective cohort consisting of patients who received a preoperative corticosteroid or lidocaine intra-articular hip injection and subsequently underwent hip arthroscopy for treatment of FAIS between 2014-2020. Patients were classified by injection received and labeled as “responders” if the injection provided pain relief. Lidocaine and corticosteroid cohorts were matched using 1:1 matching for age, BMI, and sex. Patient reported outcome (PRO) measurements including the Hip Disability and Osteoarthritis Outcome Score (HOOS), 12-item Short-Form Survey mental (SF-12 MCS) and physical component survey (SF-12 PCS), and visual analog scale (VAS) Pain were completed both preoperatively and 2-years postoperatively. Mean differences in preoperative and 2-year postoperative scores were calculated as was the percentage of patients achieving a mean clinically important difference (MCID). Floor and ceiling effects of PROs were also evaluated with 15% of patients achieving a maximum or minimum survey score deemed as significant. Results: Our cohort included 110 patients (55 lidocaine, 55 corticosteroid) with no significant differences in preoperative demographic variables (Table 1). Both cohorts demonstrated significant 2-year postoperative score improvements across all PROs, except SF-12 MCS, which was unchanged. Lidocaine non-responders demonstrated greater 2-year mean difference in all PROs, except for SF-12 MCS, when compared to lidocaine responders (Table 2). Lidocaine non-responders also achieved MCID at higher rates than responders in both HOOS Pain & VAS Pain (Table 3). There was no difference in percentage of patients achieving MCID or mean difference in PROs between corticosteroid responders and non-responders. Ceiling and floor effects were seen in 2-year postoperative PROs of a combined lidocaine & corticosteroid responder cohort. [Ceiling: HOOS ADL (34.6%) HOOS Pain (21.0%) HOOS Sport (28.4%); Floor: VAS Pain (34.6%)] Conclusions: Preoperative intra-articular hip injection response did not predict 2-year postoperative outcomes after hip arthroscopy for FAIS. Results from this study suggest that preoperative injection response should not be used in isolation to predict outcomes after arthroscopic treatment of FAIS.