Primary Arthroscopic Labral Repair in Acetabular Overcoverage: PROMs and Arthroplasty Rates at Midterm Follow-up

Abstract

Background:

Acetabular overcoverage (pincer morphology) has been suggested to be both a source of pain and dysfunction and potentially protective against osteoarthritic change.

Purpose:

To compare the minimum 5-year clinical outcomes of patients undergoing primary hip arthroscopic labral repair with a lateral center edge angle (LCEA) of ≥40° as compared with nondysplastic controls with an LCEA of 25° to 40°.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A retrospective review was performed to identify all patients who underwent primary hip arthroscopic labral repair between 2009 and 2019 at a single academic institution. Patients with an LCEA of ≥40° (pincer) were propensity-matched to nondysplastic controls with an LCEA of 25° to 40° on a 1-to-2 basis by sex, age, body mass index, and surgery year. Patient-reported outcome measures (PROMs)—including visual analog scale, Tegner activity score, modified Harris Hip Score, International Hip Outcome Tool (iHOT-12), and Hip Outcome Score were analyzed—as were reoperations and conversions to total hip arthroplasty (THA).

Results:

A total of 55 patients with pincer morphology (preoperative LCEA: 41.9°± 2.1°) were matched to 110 nondysplastic controls (LCEA: 31.2°± 4.1°), resulting in a total of 165 hips in 163 patients (67% women, mean age: 37.7 ± 9 years). Pincer patients were corrected to a mean postoperative LCEA of 38.7°± 4.1º (P < .001), with 22 pincer patients having residual overcoverage; namely, a postoperative LCEA ≥40° (range, 40°-45.8°). There were no differences between cohorts regarding intraoperative characteristics—including femoral and acetabular Outerbridge grade—as well as capsulotomy type and the presence of capsular repair (P≥ .210). At a mean 8-year follow-up (range, 5.1-13.2), there was no difference in any postoperative PROMs between pincers and controls (P≥ .215) and no difference in PROMs between patients with residual overcoverage and pincer patients with a postoperatively normalized LCEA (P≥ .291). At final follow-up, 4 patients in the pincer cohort (7%) and 21 controls (19%) converted to THA (P = .046).

Conclusion:

Patients with lateral acetabular overcoverage demonstrated similar and satisfactory postoperative PROMs at a minimum 5-year follow-up compared with propensity-matched nondysplastic controls, regardless of whether the LCEA was corrected to <40°. Of note, nondysplastic controls demonstrated a higher rate of conversion to THA, suggesting a potentially chondroprotective role for acetabular overcoverage.