Objective:To evaluate the arthroscopy-assisted reduction and internal fixation (ARIF) via the traditional anterolateral approach for the treatment of posterolateral tibial plateau fractures (PTPF).Methods:A retrospective study was conducted of the 79 patients with PTPF who had been treated from March 2014 to February 2020 at Department of Articular Surgery, Linyi Central Hospital. They were 37 males and 42 females, aged from 17 to 71 years (average, 46.0 years). According to treatment methods, they were assigned into an ARIF group (37 cases) and a control group (42 cases). The ARIF group was treated by ARIF via the traditional anterolateral approach and the ARIF varied according to the extents of articular collapse and split and displacement of fracture fragments. The control group was treated by traditional reduction and internal plate fixation of the proximal tibia. The 2 groups were compared in terms of operation time, blood loss, iliac bone grafting, hospitalization time, follow-up time, Hospital for Special Surgery (HSS) score, maximum flexion and extension, fracture healing time, Rassmussen functional and anatomical scores, visual analogue scale (VAS) pain score and complications.Results:There was no statistically significant difference in the general data between the 2 groups, showing comparability ( P>0.05). All patients were followed up for 6 to 18 months (average, 11.4 months). The operation time [(48.9±8.2) min], blood loss [(73.1±20.8) mL], hospitalization time [(9.3±2.5) d], and fracture healing time [(12.5±1.8) weeks] in the ARIF group were all significantly less than those in the control group [(55.2±9.9) min, (100.8±30.3) mL, (11.8±2.8) d and (15.1±2.1) weeks] while the HSS score [(93.5±4.6) points], maximum flexion angle (107.8°±10.4°) and Rassmussen functional score [(27.1±1.8) points] in the ARIF group were significantly higher than those in the control group [(88.4±7.4) points, 100.4°±10.0° and (26.1±2.4) points] (all P<0.05). There was no significant difference between the 2 groups in iliac bone grafting, follow-up time, maximum extension angle, Rassmussen anatomical score, VAS score, or rate of complications (all P>0.05). Conclusions:Compared with traditional surgery, ARIF which varies with the extents of articular collapse and split and displacement of fracture fragments may lead to shorter operation time, reduced surgical trauma and more accurate reduction of the articular surface. Therefore, it can be an additional choice in the treatment of PTPF.