[Efficacy of arthroscopic longitudinal capsulotomy using the indirect head of the rectus femoris as a landmark for femoroacetabular impingement and acetabular labral tears].

To evaluate the clinical efficacy of a modified outside-in longitudinal capsulotomy using the indirect head of the rectus femoris (IHRF) as an anatomical landmark in arthroscopic treatment of femoroacetabular impingement (FAI) and acetabular labral tears. Clinical data of 59 patients with FAI and labral tears undergoing hip arthroscopy at the First Hospital of Jilin University from June 2021 to May 2023 were retrospectively analyzed. The patients were divided into two groups based on surgical approach: 34 patients underwent capsulotomy using the iliocapsularis muscle as a landmark (iliocapsularis group), while 25 patients underwent IHRF-guided capsulotomy (IHRF group). Both groups received standardized procedures, including acetabuloplasty, labral repair, and cam osteoplasty. The clinical parameters (surgical time, traction time, complications), functional scores [visual analog scale (VAS) of pain, modified Harris Hip Score (mHHS), Hip Outcome Score (HOS), International Hip Outcome Tool-12 (iHOT-12), Hip Disability and Osteoarthritis Outcome Score (HOOS-12)], and radiographic outcomes [α angle, lateral center-edge angle (LCEA), Tönnis grade] were compared preoperatively and at final follow-up between the two groups. No significant differences in baseline demographics (gender, age, body mass index) were observed between the groups (all >0.05). The IHRF group demonstrated shorter surgical time [(70.6±8.8) vs (86.2±7.4) minutes] and traction time [(35.2±5.8) vs (44.6±5.3) minutes] when compared to those in the iliocapsularis group (both <0.05). All patients were followed-up for at least 12 months. Postoperatively, both groups exhibited significant improvements in VAS, mHHS, HOS, iHOT-12, and HOOS-12 scores (all <0.05). Complication rates were comparable between the IHRF and iliocapsularis group [4.0%(1/25) vs 5.9%(2/34), =0.911]. Radiographically, alpha angles decreased significantly in both groups (iliocapsularis group: 60.7°±3.2° vs 40.1°±3.1°; IHRF group: 59.9°±4.1° vs 39.9°±1.9°, both <0.05), with no intergroup differences in alpha angle, LCEA, or Tönnis grade at the final follow-up (all >0.05). Arthroscopic longitudinal capsulotomy guided by the IHRF as an anatomical landmark offers comparable efficacy to the iliocapsularis-based approach for FAI and labral tears, with advantages in procedural efficiency and precision.