Abstract:[Objective] To investigate the clinical efficacy of the posteromedial and anterolateral approaches for open reduction and in- ternal fixation (ORIF) of complex tibial plateau fractures involving the posteromedial plateau. [Methods] A total of 33 patients received OR- IF for complex tibial plateau fractures involving the posteromedial plateau through the posteromedial and anterolateral approaches in our de- partment from April 2017 to March 2021. The clinical and imaging results were observed. [Results] All patients were operated on success- fully without serious complications such as neurovascular injury, and were followed up for (23.5±8.3) months on an average, resumed full weight bearing in (17.6±2.1) weeks. Compared with those 3 months after surgery, the knee extension-flexion range of motion (ROM) and knee HSS scores significantly increased at 12 months after surgery and at the last follow-up (P<0.05), whereas the Rasmussen score re- mained unchanged (P>0.05). Radiographically, the MPTA and PTS had no significant changes at 12 months and the last follow-up com- pared with those 3 months after surgery (P>0.05), while the tibial plateau fractures healed in all patients at 10~16 weeks postoperatively. At the last follow-up, 2 patients had moderate stenosis of joint space, 8 patients had obvious osteophyte formation of the knee joint, and the de- generation was significantly deteriorated at 12 months compared with that 3 months postoperatively (P<0.05). However, no revision surgical operation was performed in anyone of them until the latest follow-up. [Conclusion] The posteromedial and anterolateral approaches for OR- IF of complex tibial plateau fractures involving the posteromedial plateau do achieve accurate reduction and firm internal fixation, which is conducive to early functional exercise of the knee joint, with few complications while satisfactory clinical efficacy.