Are Results of Arthroscopic Labral Repair Durable in Dysplasia at Midterm Follow-up? A 2-Center Matched Cohort Analysis

Background: Studies assessing dysplasia's effect on hip arthroscopy are often limited to the short term and unable to account for demographic factors that may vary between dysplastic and nondysplastic populations. Purpose: To determine the midterm failure rate and patient-reported outcomes of arthroscopic labral repair in the setting of dysplasia and make subsequent failure and outcome comparisons with a rigorously matched nondysplastic control group. Study Design: Cohort study; Level of evidence, 3. Methods: Primary arthroscopic labral repair cases at 2 centers from 2008 to 2011 were reviewed. Patients with lateral center edge angle (LCEA) <25 degrees were matched to nondysplastic controls by age, sex, laterality, body mass index (BMI), Tonnis grade, and capsular repair per a 1:2 matching algorithm. Groups were compared with a visual analog scale (VAS) for pain, modified Harris Hip Score (mHHS), and Hip Outcome Score-Sports Specific Subscale (HOS-SSS) to determine predictors of outcome and failure. Results: Forty-eight patients with dysplasia (mean LCEA, 21.6 degrees; range, 13.0 degrees-24.9 degrees; n = 25 with capsular repair) were matched to 96 controls (mean LCEA, 32.1 degrees; range, 25 degrees-52 degrees; n = 50 with capsular repair) and followed for a mean of 5.7 years (range, 5.0-7.7 years). Patients achieved mean VAS improvements of 3.3 points, mHHS of 19.5, and HOS-SSS of 29.0 points (P < .01) with no significant differences between the dysplasia and control populations (P > .05). Five-year failure-free survival was 83.3% for patients with dysplasia and 78.1% for controls (P = .53). No survival or outcomes difference was observed between patients with dysplasia who did or did not have capsular repair (P >= .45) or when comparing LCEA <20 degrees and LCEA 20 degrees to 25 degrees (P .60). BMI 30 was associated with increased revision surgery risk (P < .01). Age >35 years (P < .05) and Tonnis grade 0 radiographs (P < .01) predicted failure to reach minimal clinically important differences. Conclusion: With careful selection and modern techniques, patients with dysplasia can benefit significantly and durably from arthroscopic labral repair. The dysplastic cohort had outcomes and failure rates similar to those of rigorously matched controls at midterm follow-up. Subanalyses comparing LCEA <20 degrees and LCEA 20 degrees to 25 degrees are presented for completeness; however, this study was not designed to detect differences in dysplastic subpopulations. BMI <= 30 was associated with increased revision risk. Age >35 years and Tonnis grade 0 radiographs predicted failure to achieve minimal clinically important differences.