Arthroscopic Capsular Plication in Patients With Labral Tears and Borderline Dysplasia of the Hip: Analysis of Risk Factors for Failure
Background: Hip arthroscopy for the treatment of instability in the setting of borderline dysplasia is controversial. Capsular management in such cases is an important consideration, and plication has been described as a reliable technique, with good midterm outcomes reported when indications are appropriate.
Hypothesis: Patients with borderline dysplasia who have a lower lateral center-edge angle (LCEA) and greater age will be at a higher risk of failure after arthroscopic capsular plication.
Study design: Case-control study; Level of evidence, 3.
Methods: Data were retrospectively reviewed for all patients between 15 and 40 years of age who underwent hip arthroscopy from November 2008 to January 2015. Inclusion criteria were an LCEA between 18° and 25°, Tönnis grade ≤1, primary case with capsular plication, and minimum 2-year follow-up. Patients were excluded if they had any history of ipsilateral hip procedure or conditions such as Legg-Calve-Perthes disease, slipped capital femoral epiphysis, rheumatologic disease, and Tönnis grade ≥2. Age, sex, and body mass index data were retrieved for each patient. Patient-reported outcomes (PROs)-including modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score-Sports Specific Subscale, and a visual analog scale (VAS) for pain (0-10)-were obtained preoperatively and at a minimum of 2 years postoperatively, in addition to the postoperative International Hip Outcome Tool-12. The "success" group consisted of all patients who achieved the patient acceptable symptomatic state of mHHS ≥74 and had no ipsilateral hip surgery subsequent to their index arthroscopy. The "failure" group was composed of patients who were below the patient acceptable symptomatic state at latest follow-up or required secondary arthroscopy or conversion to total hip arthroplasty. Patient satisfaction and minimal clinically important difference were also calculated. Mean age for the failure group was applied as a cutoff age for subanalysis, and relative risk for failure was determined.
Results: Ninety patients (97 hips; 79.5%) met criteria for the success group, and 25 patients (25 hips) met criteria for the failure group. No significant differences in preoperative baseline scores or VAS were found. However, there did appear to be a trend that the failure group had lower mean preoperative scores for all PRO measures and a higher VAS score. The differences in preoperative mHHS and NAHS closely approached significance ( P = .053). Postoperative PRO, VAS, and patient satisfaction scores of the success group were significantly higher than the failure group. The failure group was significantly older than the success group (28.5 ± 7.8 vs 23.5 ± 7.5 years, P = .005). Patients >35 years old were 2.25 times more likely to fail according to relative risk (95% CI, 1.10-4.60; P = .0266). LCEA did not differ between the groups, and no other risk factors for failure were identified.
Conclusion: Stringent criteria for patient selection and meticulous repair or augmentation of the static stabilizers of the hip yielded favorable clinical outcomes in this study cohort with borderline dysplasia. Within this carefully selected group, the analysis revealed that increased age was the main risk factor for failure in the management of borderline hip dysplasia via isolated primary arthroscopic hip surgery with capsular plication.