EP8.28 Bipolar Hip Lesions Predict Inferior Mid-Term Outcomes Following Hip Arthroscopy

Abstract Background Bipolar lesions in the knee have been shown to have worse outcomes postoperatively compared to patients with unipolar lesions. However, studying the effect of bipolar hip lesions compared to unipolar lesions is not as extensively researched in the hip arthroscopy literature. Introduction The purpose of this study is to investigate the effect of bipolar hip lesions on mid-term differences in patient-reported outcomes (PROM) and achievement of clinically meaningful outcomes. Methods This was a retrospective review of prospectively collected data of patients undergoing hip arthroscopy for symptomatic labral tears. All patients were emailed PROM surveys at enrollment and 5 years after surgery. A bipolar lesion was classified as a patient with an ICRS score ≥1 for both the femur and acetabulum, and a unipolar lesion was classified as a patient with an ICRS score ≥1 for either the femur or the acetabulum, but not both. Results 42 patients met the inclusion criteria, with 14 assigned to the bipolar lesion cohort and 28 to the unipolar lesion cohort. 16 of the 42 patients (38.1%) were female. At baseline, there were no significant differences in PROMs between cohorts (all P>0.05). There were no significant differences in mean improvement from baseline to 5 years across all PROMs (all P>0.05). At 5-year follow-up, the bipolar lesion cohort reported significantly lower scores for mHHS, HOS-SSS, and iHOT-33 (all P<0.05). A linear regression model revealed that the cohort type was a significant predictor for all PROMs at 5 years after controlling for baseline scores (all P<0.05). No significant differences in MCID achievement were observed across all PROMs (all P>0.05). Patients with unipolar hip lesions achieved PASS thresholds at a significantly higher rate compared to patients with bipolar lesions for NAHS (92.9% vs 57.1%, P=0.010) and mHHS (89.3% vs 42.9%, P=0.041). SCB achievement was similar between cohorts (all P>0.05), except that the bipolar lesion cohort reported worse SCB achievement in mHHS (42.9% vs 82.1%, P=0.025). Conclusion The bipolar lesion cohort reported no differences in PROMs to the unipolar lesion cohort. However, at the 5-year follow-up, the bipolar lesion cohort reported significantly lower scores for most PROMs. Minimal differences were observed between cohorts in achieving MCID, PASS, and SCB thresholds. These findings suggest that although hip arthroscopy is still a beneficial treatment for patients with bipolar or unipolar hip lesions, patients with a bipolar hip lesion demonstrated inferior post-operative scores.