Treating a terrible triad injury of the elbow remains a challenge for orthopedic surgeons, especially in elderly patients due to the poor quality of the surrounding soft tissue and bony structures. In the present study, we propose a treatment protocol using an internal joint stabilizer through a single posterior approach and analyze the clinical results. We retrospectively reviewed 15 elderly patients with terrible triad injuries of the elbow who underwent our treatment protocol from January 2015 to December 2020. The surgery involved a posterior approach, identification of the ulnar nerve, bone and ligament reconstruction, and the application of the internal joint stabilizer. A rehabilitation program was initiated immediately after the operation. Surgery-related complications, elbow range of motion (ROM), and functional outcomes were evaluated. The mean follow-up period was 21.7months (range, 16-36months). ROM at the final follow-up was 130° in extension to flexion and 164° in pronation to supination. The mean Mayo Elbow Performance Score was 94 at the final follow-up. Major complications included breaking of the internal joint stabilizer in 2 patients, transient numbness over the ulnar nerve territory in one, and local infection due to irritation of the internal joint stabilizer in one. Although the current study involved only a small number of patients and the protocol comprised two stages of operation, we believe that such a technique may be a valuable alternative for the treatment of these difficult cases. 4.