Background Double plate osteosynthesis is the standard treatment for intra-articular fractures of the distal humerus.However,there is still controversy concing dual plate positions in terms of providing optimal stability.The purpose of this retrospective study was to compare the clinical outcomes in patients with type C intra-articular distal humeral fractures using perpendicular and parallel plating methods.Methods Between March 2008 and June 2011,a total of 45 patients with type C distal humerus fractures were treated using two different dual plating methods.Of them,24 patients were treated by perpendicular plating (group Ⅰ) and 21 patients were treated by parallel plating (group Ⅱ).The surgical time,blood loss,and union time were compared between the two groups.The fiexion-extension arc,the total range of flexion and extension at the end of follow-up were compared between the two groups.The Mayo Elbow Performance Score (MEPS) was used to determine the elbow functional results.Results All patients were followed up.The mean duration of follow-up was 16 months (range 12-25 months) in group Ⅰ and 15.5 months in group Ⅱ (range 12-25 months).There were no significant differences in the surgical time,blood loss,and the bone union time between the two groups.In group Ⅰ,the mean elbow flexion-extension arc was 101° and the mean MEPS was 85 points.The rate of excellent and good results was 87.5％.In group Ⅱ,the mean flexion-extension arc was 100° and the mean MEPS was 86.1 points.The rate of excellent and good results was 90.5％.There were no significant differences in the MEPS,flexion-extension arc,and the total range of flexion and extension between the two groups.Conclusions Perpendicular and parallel plate configurations with the appropriate surgical techniques can provide anatomical reconstruction and stable fixation of type C intra-articular distal humeral fractures and allow early mobilization of the elbow after an operation.The occurrence of post-operative elbow stiffness can be reduced and good outcomes can be obtained.