Bilateral Hip Arthroscopy: Can Results From Initial Arthroscopy for Femoroacetabular Impingement Predict Future Contralateral Results?

Purpose: To determine the degree of correlation of radiographic measurements, degree of correlation of intraoperative pathology, and difference in outcomes between sides of patients requiring staged bilateral hip arthroscopy. Methods: Two high-volume hip preservation centers retrospectively reviewed hip preservation databases for staged bilateral hip arthroscopies conducted between 2008 and 2015. Patients were separated into those who presented with bilateral hip pain and those that presented with unilateral pain and developed contralateral pain >2 years later. Patients were analyzed for radiographic correlation (alpha angle, lateral center edge angle, anterior center edge angle, magnetic resonance imaging alpha angle, Tönnis grade) and correlation of intraoperative pathology (acetabular labrum articular disruption grade, Outerbridge grade/location, Villar class ligamentum teres tears, labral tear location, symmetry of Seldes tear types, and the differences between operative procedures). Patient-reported outcomes were analyzed (modified Harris Hip Score, Non-Arthritic Hip Score, International Hip Outcome Tool-12, hip outcome score-sport specific subscale, visual analog scale, patient satisfaction). Correlative tests included Pearson and Spearman; univariate and multivariate analysis for differences included χ-square test and Student t tests for ordinal and continuous variables respectively. Results: A total of 133 of 2,705 patients (4.6%) underwent bilateral hip arthroscopy. Radiographic alpha angle, magnetic resonance imaging alpha angle, lateral center edge angle, and anterior center edge angle demonstrated strong correlation (Pearson's coefficients 0.651, 0.648, 0.644, 0.667, respectively, P < .0001). Tönnis grade was weakly correlated (Pearson's coefficient 0.286, P = .001). Intraoperative pathology was moderately correlated (Pearson's coefficients for acetabular Outerbridge location, 0.300, P = .0170; acetabular labrum articular disruption, 0.490, P < .0001; acetabular Outerbridge; 0.530; P < .0001; femoral head Outerbridge, 0.459, P < .0001; Villar class, 0.393, P < .0001; and labral tear location, 0.468, P < .0001). Labral tear Seldes type was compared with Bowker's symmetry test and there was no significant difference between sides. There were no significant differences in surgical interventions performed between sides. Patients with bilateral hip arthroscopies significantly improved in all measured patient-reported outcomes and had a high patient satisfaction after both procedures. Final patient-reported outcomes and change in patient-reported outcomes were not different between procedures; follow up ranged from 3 months to 8 years. Conclusions: This study demonstrated an incidence of 4.6% of patients who require bilateral hip arthroscopy. These patients can expect significant improvement after surgical intervention. Patients that had 1 side done gained similar improvement when the contralateral side was performed. Preoperative radiographic, intraoperative pathology, and procedures performed were similar between hips. Level of Evidence: Level III, retrospective cohort study.