Comparison of different treatment approaches for coronoid process fracture in terrible triad injury: a multicenter, randomized controlled study

Purpose The purpose of the study was to compare the functional results of different treatment approaches for the fracture of the coronoid process in terrible triad injury (TTI). Methods This prospective randomized controlled trial included participants from seven level-1 trauma centres in China. All patients were randomly assigned to three groups, wherein different approaches were applied to treat coronoid fracture: group A) internal fixation of the coronoid process without external fixation or splint (ORIF group), B) external fixation using a hinged fixator without internal fixation (Exfix group), and C) long-arm plaster for two to three weeks postoperatively without internal fixation of coronoid process (Plaster group). Early active motion exercises within the limits of pain were started immediately after surgery under the supervision of a physical therapist. Outcomes were evaluated at regular intervals over the subsequent 12 months. Results A total of 65 patients (22 patients in Group A, 21 in Group B, and 22 in Group C) were included in this trial from January 2016 to January 2019. The average arc of elbow motion was 114.1° ± 8.92°. The average flexion and flexion contracture were 126.4° ± 11.2° and 12.3° ± 7.7°, respectively. The arcs of forearm rotation of the elbow for each group were 145.41° ± 9.36°, 143.38° ± 9.79°, and 143.86° ± 10.95°, respectively. The MEPS for each group were 86.82 ± 9.7, 86.67 ± 9.92, and 85.23 ± 8.66, respectively. The DASH score for each group were 18.26 ± 19.31, 18.85 ± 15.02, and 20.19 ± 13.59, respectively. Conclusion All three approaches in our trial showed similar functional results in the long-term survey. Patients treated with external fixation without internal fixation of the coronoid process showed less pain during early mobilization and acquired maximum flexion within a short duration after surgery.