Objective To investigate the effectiveness of hip arthroscopy in the treatment of patients with femoroacetabular impingement (FAI) combined with ligamentum teres injury. Methods A retrospective analysis was conducted on 23 patients (23 hips) with Cam-type FAI combined with ligamentum teres injury who met the selection criteria between April 2022 and May 2024. The cohort included 12 males and 11 females, with a mean age of 29.16 years (range, 16-57 years). According to Tönnis classification, there were 5 cases of grade 0, 10 cases of grade Ⅰ, and 8 cases of grade Ⅱ in hip osteoarthritis The disease duration ranged from 6 to 24 months, with an average of 12 months. Under hip arthroscopy, hypertrophic synovium and the damaged ligamentum teres were debrided, while the torn labrum and cartilage were repaired, and femoral head-neck osteoplasty was performed to eliminate impingement, restore the normal morphology of the acetabulum and femoral head-neck, and suture the joint capsule.Acetabular lateral center-edge angle (LCEA) and α angle (reflecting the degree of non-sphericity at the femoral head-neck junction) were measured before and after operation, and the modified Harris hip score (mHHS), the International Hip Outcome Tool-12 (IHOT-12), and the visual analogue scale (VAS) score for pain were evaluated. ResultsThe operation was successfully completed in all patients. The incisions healed by first intention after operation, and there were no perioperative complications such as iatrogenic cartilage injury, fracture, infection, neurovascular traction injury, and lower extremity venous thrombosis. All the 23 patients were followed up 12-24 months, with an average of 14.6 months. The pain of hip joint was significantly relieved, and the function of hip joint was improved; no complication such as joint stiffness, joint instability, and osteonecrosis of the femoral head occurred. The α angle, VAS score, mHHS score, and iHOT-12 score were significantly better than those before operation at last follow-up (P<0.05). Conclusion Hip arthroscopy is a safe and effective treatment for patients with FAI combined with ligamentum teres injury, which can achieve satisfactory effectiveness.