Objective To report the clinical results of surgical treatment of fracture of the anteromedial facet of the coronoid process in terrible triad injury.Methods Of the 59 patients with terrible triad injury of the elbow,17 were surgically treated for fracture of the anteromedial facet of the coronoid process from July 2010 to July 2014.They were 12 men and 5 women,from 29 to 70 years of age (average,50 years).By the Mason classification for the radial head fractures,2 cases were type Ⅰ,13 type Ⅱ and 2 type Ⅲ;by the O'Driscoll classification for coronoid process fractures,one was type Ⅰ,14 were type Ⅱ and 2 type Ⅲ.All patients were treated through combined approaches.The lateral Kocher approach was used to fixate or replace the radial head and to repair the lateral ligament complex;the anteromedial approach was used to fixate the coronoid process fracture and to explore and repair the medial collateral ligament if necessary.Fracture union,implant loosening,ectopic ossification,regression and articular alignment were assessed on the postoperative X-rays.At final follow-ups,the elbow function was evaluated using Mayo elbow performance score (MEPS) and Broberg & Morrey grading system for traumatic arthritis.Results The average follow-up duration for the 17 patients was 32 months (range,from 24 to 60 months).Final follow-ups showed that the mean arc of flexion-extension was 97° (from 70° to 120°),the mean extension limitation 23° (from 0 to 40°),the mean arc of forearm rotation 139° (from 90° to 145°),the mean pronation 71° (from 60° to 90°)and the mean supination 67° (from 60° to 85°).The MEPT scores averaged 87 points (from 80 to 100 points),yielding 7 excellent,8 good and 2 fair cases.By the Broberg & Morrey grading,there were 4 cases of grade 1 and one of grade 2.No evidence of elbow instability,nonunion or implant failure was found.Ectopic ossification around the elbow happened in 4 cases,transient ulnar nerve palsy was found in one,and the Kirschner wire was removed operatively in 2 because it had loosened after fracture union.Conclusion The treatment of anteromedial coronoid fractures in terrible triad injury should be anatomically reduced through direct exposure and fixated rigidly.