Abstract:Objective To investigate the effect of proximal fibula fracture on the surgical prognosis of complex tibial plateau fracture involving posterior lateral condyle. Methods A retrospective analysis was performed on 118 patients with Schatzker type Ⅳ,Ⅴ and Ⅵ fractures of tibial plateau involving the posterolateral condyle treated in our hospital from January 2014 to December 2019,including 60 males and 58 females.The age ranged from 18 to 75 years,with an average age of (51.8±10.6) years.Group A1,A2,B1 and B2 were divided according to whether proximal fibular fracture and posterolateral bracing plate fixation were present.Group A1 had no proximal fibular fracture but posterolateral bracing plate fixation,with a total of 30 cases.There were 32 cases in group A2 without proximal fibula fracture or posterolateral support plate fixation.Group B1 had proximal fibula fracture and posterolateral bracing plate fixation,with a total of 28 cases.There were 28 patients in group B2 with proximal fibula fracture without posterolateral plate fixation.The operation time,intraoperative bleeding,tibial plateau angle (TPA),posterior slope angle (PA) and the excellent and good rate of knee score in hospital for special surgery (HSS) were compared among A1,A2 and B1,B2 groups.Results All 118 patients were followed up for 12 to 16 months,with an average of (13.2±1.5) months.At the last follow-up,there were no significant differences in the excellent and good rates of TPA,PA and HSS knee score between group A1 and group A2 (P>0.05).There were statistically significant differences between group B1 and group B2 in operation time,blood loss and the excellent and good rate of TPA,PA and HSS knee score in the last follow-up (P<0.05).118 cases had no infection,loosening or or broken of internal fixation and peroneal nerve injury.Conclusion In patients with Schatzker Ⅳ,Ⅴ and Ⅵ fractures of the tibial plateau complicated with proximal fibular fractures and involving the posterolateral condyle,posterolateral support plate fixation can more effectively reduce the loss of secondary reduction and obtain a better prognosis.