Given that the LT contributes to the hip joint stability, we hypothesized that patients with a partial LT tear would develop hip osteoarthritis earlier than those with an intact LT. However, no studies have reported clinical and radiologic results of the long-term effects of partial LT tears. However, The HA debridement procedure has shown excellent short-term results by reducing pain and improving the function of partial LT tears. has found that among patients who underwent HA due to femoroacetabular impingement (FAI) and labral tear, those with a complete rupture of the LT had a 3-fold increase in the relative risk of undergoing total hip arthroplasty (THA) compared to those with an intact LT. The role of LT for the biomechanics and function of the hip joint has not been fully described in the literature, and studies on the relationship between LT injury and hip joint injury are lacking.Ī match-controlled study by Maldonado et al. The LT is known to help distribute synovial fluid into the joint and plays an important role in enhancing hip stability. have reported that the LT possesses a free nerve ending that is responsible for pain, pressure and deep sensation. With the development of hip arthroscopy (HA) in recent decades, interest in and the importance of the function and role of the LT has been gradually emphasized. Studies on the function of the ligamentum teres (LT) were first published in the 19th century. Patients with partial LT tear showed a higher grade of chondral damage, experienced decreased exercise capacity and had significantly worsened Tönnis grades, suggesting hip osteoarthritis progression compared to those with an intact LT. Regarding the Tönnis grade, significant differences were found only at the final follow-up ( P = 0.020). At the last follow-up, Group A patients experienced more difficulty performing sports activities than Group B patients ( P = 0.056), and significantly, more Group A patients had stopped exercising despite their active participation in sports preoperatively ( P = 0.002). Chondral damage to the acetabular and femoral head detected intraoperatively was significantly different between the groups ( P = 0.005 and P < 0.001). The Tönnis grade was assessed preoperatively and at the last follow-up for radiologic evaluation. Patients’ satisfaction with the surgery and changes in postoperative sports ability in those who had previously been active in sports were assessed at the last follow-up. Clinical items were assessed preoperatively and at the last follow-up. The grade of chondral damage was measured intraoperatively. Debridement and thermal shrinkage were performed for LT tears. All patients underwent partial labral debridement and femoroplasty. Among the patients who underwent HA for a cam-type FAI diagnosis with a labral tear, 28 patients (28 hips) with a partial LT tear and 87 patients (99 hips) with an intact LT were assigned to Groups A and B, respectively. We aimed to compare clinical and radiologic outcomes in patients with cam-type femoroacetabular impingement (FAI), with and without a partial ligamentum teres (LT) tear, who underwent hip arthroscopy (HA) with ≥10 years of follow-up.