Prognostic Value of the Lateral Center-Edge Angle in Hip Arthroscopy for Femoroacetabular Impingement: A Retrospective Cohort Study.

PURPOSE: Our study hypothesizes that the prognostic value of sourcil-based lateral center-edge angle (LCEAS) measurements is superior to rim-based (LCEAR) measurements in predicting clinical outcomes of hip arthroscopy for femoroacetabular impingement (FAI). The purpose of our study is to compare these measurement techniques and to identify the threshold values that predict successful patient outcomes. MATERIALS AND METHODS: We retrospectively analyzed 125 patients who underwent hip arthroscopy for FAI, with a minimum follow-up of two years. Using both sourcil- and rim-based techniques, we obtained lateral center-edge angle (LCEA) measurements from standardized pelvis anteroposterior radiographs. The modified Harris hip score (mHHS), Nonarthritic Hip Score (NAHS) and visual analog scale (VAS) for pain were used to evaluate clinical outcomes. We performed receiver operating characteristic (ROC) analyses to determine LCEA cutoffs associated with the Patient Acceptable Symptom State (PASS). Multivariate logistic regression analyses identified independent predictors of favorable outcomes. RESULTS: Postoperative LCEAS decreased from 31.1°±5.4° to 25.8°±6.6° (P=0.003), whereas postoperative LCEAR decreased from 38.7°±6.7° to 32.8°±6.4° (P=0.002). Overall, 80.8% of patients achieved PASS based on mHHS (≥83.3). ROC analysis identified postoperative LCEAS thresholds of ≤28.9° and ≤28.25° as predictors of PASS based on mHHS (AUC=0.702) and NAHS (AUC=0.740), respectively. Multivariate analysis confirmed postoperative LCEAS as an independent predictor of favorable clinical outcomes. CONCLUSION: Postoperative LCEAS thresholds of around 28.9° are independently associated with favorable clinical outcomes following hip arthroscopy for FAI. The improved prognostic information provides the rationale for the use of LCEAS over LCEAR in surgical planning and outcome prediction.