Factors associated with treatment failure after hip arthroscopic surgery for the patient with femoroacetabular impingement secondary to Legg-Calvé-Perthes disease

Legg-Calvé-Perthes disease (LCPD) leads to complex hip deformities that often result in femoroacetabular impingement (FAI). While traditional open surgeries have been used to address these deformities, hip arthroscopy has emerged as a minimally invasive alternative. However, the factors determining successful outcomes in arthroscopic management of LCPD-related FAI remain poorly defined. This study aims to compare clinical outcomes between successful and failed cases following hip arthroscopic surgery for FAI secondary to LCPD and identify factors associated with treatment failure to optimize patient selection. We retrospectively analyzed patients who underwent hip arthroscopy for FAI secondary to LCPD from 2011 to 2023. Patients with less than 2-year follow-up or incomplete records were excluded. Treatment failure was defined as requiring revision surgery, experiencing complications, or failing to achieve both the minimal clinically important difference (9.1 points) and Patient Acceptable Symptom State threshold (72 points) on the modified Harris Hip Score. We evaluated patient characteristics, clinical outcomes, radiographic measurements including lateral center edge angle (LCEA) and vertical center anterior angle (VCAA), preoperative radiographic severity using Tönnis grade, lateral pillar classification, and Stulberg grade, and compared these factors between success and failure groups. The study included 15 hips in 14 patients. Nine hips achieved successful outcomes, while six hips were considered failures. The failure group was statistically significantly older (35.5 years versus 20.3 years, P = 0.047) with decreased acetabular coverage, showing smaller LCEA (19.3° versus 30.2°, P = 0.046) and VCAA (14.7° versus 33.3°, P = 0.033). The failure group demonstrated higher frequencies of preoperative Tönnis grade ≥2, lateral pillar classification ≥B, and Stulberg grade ≥4, indicating more severe degenerative changes and deformity. No statistically significant differences were observed in gender distribution or duration of symptoms between the groups. Forty percent of patients experienced treatment failure after hip arthroscopic surgery for FAI secondary to LCPD. Advanced age, decreased acetabular coverage, and severe preoperative radiographic changes were associated with treatment failure. These findings suggest careful patient selection based on these factors is crucial for successful arthroscopic treatment in this patient population. Level III.