Objective To investigate the effect of medial collateral ligament (MCL) repair and coronoid process fracture fixation on stability of the Terrible Triad of the elbow. Methods CT and MRI scan images of elbow joints from one healthy 28-year-old male volunteer were used to establish three elbow models. Model A: normal model. Model B: repair of coronoid process fractures, without MCL repair. Model C: repair of MCL, without repair of ulnar coronoid processes. Longitudinal loads were applied on the three models to analyze the displacement and stress distributions of the elbow joint under different working conditions and compare the stability of the elbow joint. Results The displacement and stress distributions of the three models were similar. The maximum displacement and maximum stress of the articular surface were located at the ulna pulley notch, while the minimum displacement was located at the coronoid process and its medial side. The minimum stress was located at the lower lateral side of the coronoid process. There were no statistical differences in the maximum displacement and stress among the three models (P>0.05). Conclusions When the lateral column is stable, the effect of repairing the MCL and fixing the fracture block of ulnar coronoid process is similar.