Objective:To investigate the clinical effects of a single lateral-rectus approach (LRA) in the Ti-Robot-assisted treatment of acetabular fractures involving the posterior column.Methods:A retrospective study was conducted to analyze the clinical data of 16 patients with acetabular fracture who had been admitted to Department of Trauma Orthopedics, Taihe Hospital from August 2021 to March 2023. There were 13 males and 3 females with a mean age of 51.5 (35.8, 56.8) years. By the Judet-Letournel classification, there were 4 anterior and posterior semi-transverse fractures, 2 T-shaped fractures, and 10 double-column fractures. The time from injury to operation was 6.0 (5.3, 7.8) d. All their acetabular fractures involving the posterior column were treated by a single LRA with the assistance of a Ti-Robot. Operation time, blood loss, complications, quality of fracture reduction, modified Merle d'Aubigné & Postel scores and acetabular recovery at the last follow-up were recorded.Results:In this cohort, the operation time was (4.1±0.6) h and the blood loss 400 (300, 575) mL. By the Matta evaluation, the fracture reduction was excellent in 10 cases, good in 5 cases, and poor in 1 case. The follow-up time was (11.3±3.9) months. Bone union was achieved in all fractures after 3.0 (2.3, 4.0) months. By the modified Merle d'Aubigné & Postel scores at the last follow-up, 9 cases were excellent, 6 cases were good and 1 case was fair. Injury to the lateral femoral cutaneous nerve occurred in 1 patient, and deep venous thrombosis in 6 patients. Follow-ups revealed no iatrogenic vascular injury, loosening or rupture of internal fixation, or incision infection.Conclusion:A single LRA approach can be used in the minimally invasive treatment assisted by a Ti-Robot for acetabular fractures involving the posterior column, demonstrating advantages of minimal invasion, high reduction quality and good functional recovery of the hip joint.