No Correlation Between Depth of Acetabuloplasty or Postoperative Lateral Center-Edge Angle on Midterm Outcomes of Hip Arthroscopy With Acetabuloplasty and Labral Repair

Abstract

Background: The treatment of pincer deformity in hip arthroscopy remains controversial, with some authors advocating that over resection may risk early joint deterioration. The role of acetabular resection depth and postoperative acetabular morphology on postoperative outcomes has yet to be defined. Purpose/Hypothesis: This study measures the influence of acetabular resection depth and postoperative lateral center-edge angle (LCEA) on minimum 5-year patient-reported outcomes (PROs), revision rates, and conversion to total hip arthroplasty using a single surgeon’s prospective database. We hypothesized that patients with acetabular resections >10°, as measured by LCEA, or patients with postoperative LCEA outside the normal range of 25° to 35° would have lower PROs, higher revision rates, and higher conversion to total hip arthroplasty at midterm follow-up. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 192 patients who underwent primary hip arthroscopy with acetabuloplasty and labral repair by a single surgeon with a minimum 5-year follow-up met the inclusion criteria. Preoperative and postoperative LCEAs were measured on supine anteroposterior radiographs, and patients were divided into cohorts based on LCEA and acetabular resection depth. Cohorts for postoperative LCEA were <20° (dysplasia), 20° to 25° (borderline dysplasia), 25° to 35° (normal), and >35° (borderline overcoverage). Cohorts for acetabular resection depth were <5°, 5° to 10°, and >10° difference from preoperative to postoperative LCEA. Outcome measures included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), 12-Item Short Form Health Survey, modified Harris Hip Score, Hip Outcome Score, satisfaction scores, revision rates, and conversion to arthroplasty rates. Results: Patients significantly improved in all outcome score measures at final follow-up. There were no statistically significant differences in PRO scores or conversion to total hip arthroplasty between any cohorts in the postoperative LCEA group. There were more revisions in the 25° to 35° cohort than the other cohorts (P = .02). The 5-10° resection depth cohort demonstrated a higher postoperative WOMAC score (P = .03), but otherwise no statistically significant differences were seen between resection depth cohorts in the remaining postoperative outcomes scores, revision rates, or conversion to total hip arthroplasty rates. Conclusion: Patients with postoperative LCEA values outside the normal reference range and with large resections perform similar to those with normal postoperative LCEA values and smaller resections at a minimum 5-year follow-up.