BACKGROUND The objective of this investigation was to assess the effectiveness of using T-shaped steel plates through the anterior lateral approach and Gerdy's tubercle osteotomy for treating posterior lateral tibial plateau fractures. MATERIAL AND METHODS A retrospective analysis was conducted on clinical data from 20 patients, aged on average 53.9±10.36 years, who were admitted for tibial plateau fractures involving the posterior lateral condyle between January 2019 and October 2022. The fixation and reduction of the posterior lateral bone block were performed using the anterior lateral approach combined with Gerdy's tubercle osteotomy to address the posterior lateral tibial plateau fracture. Post-surgery assessment was conducted using the Hospital for Special Surgery (HSS) knee combined score. RESULTS During the 12-24 (14.2±1.7) month postoperative period, we conducted 20 surgeries. Within 9 to 12 weeks, fracture healing transpired without any complications such as incision infection, nerve injury, or fracture displacement being detected. Assessment of knee joint function at the final follow-up was conducted using the HSS knee combined score, with results indicating 16 cases rated as excellent, 3 cases as good, and 1 case as fair. CONCLUSIONS In tibial plateau fractures impacting the posterior lateral condyle, the anterior lateral approach, combined with Gerdy's tubercle osteotomy, allows for direct exposure and manipulation of the posterior lateral bone block fracture. Using a T-shaped support plate and a lateral locking plate provides a reliable method for fracture fixation, aiding in convenient surgical positioning and intraoperative fluoroscopy. The treatment approach effectively manages fractures located on the posterior lateral aspect of the tibial plateau.