Objective To investigate the effect of modified terolateral and posterolateral approach in open reduction and internal fixation in patients with posterolateral tibial plateau fractures. Methods The data of 244 patients of fracture were retrospectively, Patients selected for the intraoperative modified anterolateral approach were included in the modified anterolateral group, Patients with an intraoperative posterolateral approach were included in the posterolateral group, 122 baseline data were obtained by the propensity matching score method, Observe the operation-related recovery indicators of the two groups, evaluate the joint reduction effect of 1 week in the two groups, compare the knee mobility before and 1 month after surgery, change the knee function at different time points [Knee function Scale (HSS) at different time points], The occurrence of postoperative complications was recorded in both groups. Serum bone metabolism indexes [osteocalcin (BGP), type I procollagen carboxyterminal peptide (PICP), total procollagen I N terminal propeptide (PINP) levels and the bone resorption marker type I collagen hydroxyterminal peptide (β -CTX)] were compared before and 1 month after surgery between the two groups. Results The operation time and incision healing time in the modified terolateral group were significantly shorter than those in the posterolateral group (P <0.05), The intraoperative blood loss was significantly less than that in the posterolateral group (P <0.05); At 1 week in the modified anolateral group was significantly higher than in the posterolateral group (90.16% VS 60.66%, P<0.05); One month after the surgery, The maximum angle of extension and flexion in both groups was significantly greater than preoperative (P <0.05), The modified anolateral group was significantly larger than the posterolateral group (P <0.05); The HSS scores gradually improved with time in both groups, Two sets of time point effect, group effect and interaction effect between time point and group, The differences were all statistically significant (P <0.05), Two of these groups had significantly higher HSS scores at 1 and 3 months than 1 week after surgery, And the modified anolateral group was significantly higher than the posterolateral group (P <0.05); The overall incidence of postoperative complications in the modified anterolateral group was significantly lower than that in the posterolateral group (4.10% VS 13.11%, P<0.05); In Group 2, the serum BGP and PICP levels were significantly increased compared with the preoperative level (P <0.05), Serum level of Total-PINP and β -CTX were significantly reduced compared with the preoperative level (P <0.05), The change of change in the observation group was significantly greater than that in the control group (P <0.05). Conclusion Compared with the posterolateral approach, open reduction internal fixation intraoperative application of modified anterolateral approach treatment tibial platform posterolateral fracture patients can shorten the operation time, reduce intraoperative bleeding, promote incision and fracture healing, surgical reduction effect is significant, and can significantly improve the knee motion and function, reduce postoperative complications, and effectively improve the bone metabolism index.