Objective To evaluate the treatment of lateral tibial plateau fractures involving the posterolateral condyle with double plate fixation via the combined anterolateral and posterolateral approaches.Methods From January 2013 to August 2015,12 patients with lateral tibial plateau fracture involving the posterolateral condyle were treated by double plate fixation via the combined anterolateral and posterolateral approaches.They were 8 males and 4 females,with an average age of 36.9 years (range,from 23 to 58 years).According to the Schatzker classification,we had 8 ones of type Ⅱ,3 ones of type Ⅴ and one of type Ⅵ.Firstly,the posterolateral condylar fractures were stabilized temporarily by the Kirschner wire after reduction through the posterolateral approach.Secondly,the lateral tibial plateau fractures were dealt with via the anterolateral approach,and fixated with a proximal tibial locking plate.Finally,a T-shaped plate for the distal radius was used to support the posterolateral condyle.The clinical and radiographic results were evaluated using the Hospital for Special Surgery (HSS) knee score and the Rasmussen Score,respectively.Results The average operative time was 143.3 min (range,from 110 to 210 min);the average intraoperative blood loss was 190.0 mL (range,from 100 to 300 mL).The follow-ups for the 12 cases ranged from 12 to 24 months (average,16.6 months).All the cases obtained clinical healing after 12 to 24 weeks (average,16 weeks).At the last follow-up,the HSS knee-scores ranged from 65 to 98 points (average,84.6 points),giving 7 excellent cases,3 good ones and 2 fair ones.The Rasmussen radiological scores ranged from 13 to 18 points (average,17.1 points),giving 8 excellent and 4 good cases.Conclusions The combined anterolateral and posterolateral approaches can offer excellent exposure for articular reduction and fixation with double plates,achieving satisfactory radiological and functional results in lateral tibial plateau fractures involving the posterolateral condyle.First reduction of the posterior lateral condylar fractures,followed by reduction and fixation of the anterolateral plateau fractures and finally fixation of the lateral condylar fractures,can lead to effectively improved knee function for the patients.