Objective To report the operative procedures and clinical outcomes of open reduction and internal fixation for the treatment of tibial plateau fractures involving anteromedial margin caused by hyperextension varus injury.Methods From December 2013 to December 2015,11 patients with tibial plateau fracture involving anteromedial margin caused by hyperextension varus injury were treated at our department.They were 6 males and 5 females with a mean age of 42.3 years (range,from 19 to 65 years).Simple medial column fracture happened in 2,fractures of medial and lateral columns in 4,fractures of medial and posterior columns in 3,and 3-column fractures in 2 cases.The cortical bone fractures of anteromedial margin were fixated by open reduction and internal fixation using self-clipped joint line plating.Bone grafting was conducted if necessary.Results The 9 patients were followed up for an average of 17.6 months (range,from 12 to 30 months).All the fractures healed.The average time for radiographic bony union and full weight bearing was 11.4 weeks (range,from 9 to 14 weeks) and 16.1 weeks (range,from 14 to 19 weeks),respectively.On average,the Rasmussen's radiological grading scored 16.9 (range,from 14 to 18)immediately after operation;the Hospital for Special Surgery scores of all the patients at 12 months postoperatively averaged 89.1 (range,from 75 to 94),yielding an excellent to good rate of 92.3％.The average range of motion of the affected knee was from 2.3° to 125.1°.There were significant differences in both tibial plateau angle and posterior slope angle on radiography between preoperation and postoperation (P ＜ 0.05).There were no significant differences in either tibial plateau angle or posterior slope angle on radiography between immediate postoperation and 12 months postoperation (P ＞ 0.05).Partial incision necrosis occurred postoperatively in one case which was uneventfully healed after wound management.One case complicated with preoperative common peroneal nerve injury reported dorsal sense of numbness which was healed after administration of neurotrophic drugs.No screw loosening,plate breakage or fixation failure was found during follow-ups.Conclusions It is difficult to treat the tibial plateau fractures involving anterumedial margin caused by hyperextension varus injury.Internal fixation with joint line plating is an appropriate treatment for this fracture pattern,leading to satisfactory clinical outcomes.