Labral Hypoplasia by Preoperative Magnetic Resonance Imaging Predicts Higher Revision and Arthroplasty Risk After Hip Arthroscopy for Femoroacetabular Impingement Syndrome at 10 Year Follow-Up.

Abstract

To determine the association between labral width as measured on preoperative magnetic resonance imaging (MRI) and patient-reported outcomes, achievement of clinically significant thresholds, and reoperation rates in hip arthroscopy for femoroacetabular impingement syndrome (FAIS) at minimum 10-year follow-up. A retrospective review of a prospectively gathered database of hip arthroscopy patients from August 2012 to June 2014 was conducted. Inclusion criteria were patients ≥18 years with clinically and radiographically confirmed FAIS and labral tearing who underwent primary hip arthroscopy with labral repair or debridement and had ≥10 years of follow-up. MRI labral width measurements were performed by 2 blinded musculoskeletal radiologists at standardized clockface locations using a validated technique. Outcomes were assessed using the modified Harris Hip Score (mHHS) and Non-Arthritic Hip Score (NAHS). Patients were classified as hypoplastic if they had a labral width below the mean on 2 or more views. Outcomes and reoperation rates were compared between groups using independent samples t-tests for continuous variables and chi-square tests for categorical variables. A total of 83 patients (83 hips; 65.9% follow-up) with a mean age of 42.93 ± 13.74 years and body mass index of 25.22 ± 4.51 kg/m² were included, with a mean follow-up of 11.30 ± 0.47 years. Patients were categorized into hypoplastic (n = 42) and nonhypoplastic (n = 41) groups. There was no significant difference between hypoplastic and nonhypoplastic groups with respect to age, sex, smoking status, or intraoperative procedures. Additionally, there were no significant intergroup differences in mHHS or NAHS improvement at 5 or 10 years postoperatively. Both groups showed high achievement of the mHHS minimal clinically important difference threshold at 10-year follow-up with no significant difference (nonhypoplastic: 90.3% vs hypoplastic: 85.2%, P = .549). There was also no difference achievement of the patient acceptable symptom state (nonhypoplastic: 64.5% vs. hypoplastic: 70.4%, P = .636). However, the hypoplastic group had a significantly higher rate of revision arthroscopy (28.6% vs 9.8%, P = .030) and conversion to total hip arthroplasty (21.4% vs 4.9%, P = .026) when compared with the nonhypoplastic group. Hypoplastic labral width on preoperative MRI was associated with an increased risk of revision hip arthroscopy and conversion to total hip arthroplasty at 10 year follow-up in patients with FAIS. Level III, retrospective comparative case series.