Healed Acetabular Labrum on Postoperative Magnetic Resonance Imaging Is Associated With Superior Achievement of Clinically Significant Outcomes After Hip Arthroscopy for Femoroacetabular Impingement Syndrome: Minimum 2-Year Follow-Up.

PURPOSE: To investigate the relation between labrum healing status measured via magnetic resonance imaging and clinical outcomes in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome. METHODS: Patients who underwent primary hip arthroscopy for femoroacetabular impingement syndrome at our institute between 2012 and 2020 with a minimum 2-year follow-up were retrospectively reviewed. Patients were divided into 4 groups based on the change in labral injury grades from preoperative to postoperative: unchanged group, improvement group, healed group, and worsening group. Supine anteroposterior hip radiographs, 45° Dunn view radiographs, computed tomography scans, and magnetic resonance imaging scans were obtained for all patients preoperatively and postoperatively. Preoperative and final follow-up scores on the visual analog scale for pain and the modified Harris Hip Score were compared between groups with the 1-way ANOVA. RESULTS: A total of 220 patients (mean age, 37.3 years; 104 men, 116 women) were included, with a minimum follow-up time of 2 years. The percentages of the total number of patients in the unchanged group, improvement group, healed group, and worsening group are 28.6%, 23.6%, 38.2%, and 9.6%, respectively. The healed group, the unchanged group, and the worsening group had significantly lower preoperative labral injury grades compared with the improvement group (P < .001). The healed group showed a superior achievement rate of the minimal clinically important difference for the visual analog scale compared with the worsening group (P = .032). The healed group showed a superior achievement rate of the patient acceptable symptomatic state for the modified Harris Hip Score compared with the worsening group and the unchanged group (P = .004). CONCLUSIONS: Magnetic resonance imaging-measured labral healing may be associated with superior achievement of clinically significant outcomes, particularly when the labrum is healed compared with worsened or unchanged status. However, this classification requires validation, and absolute postoperative modified Harris Hip Score and visual analog scale scores did not differ significantly between groups. LEVEL OF EVIDENCE: Level III, retrospective comparative case series.