ObjectiveTo investigate the feasibility of modified classification of terrible triad of the elbow and the effectiveness of treatment strategy which was chosen by modified classification results. MethodsBetween March 2007 and November 2013, 12 cases of terrible triad of the elbow were treated by operation. There were 5 males and 7 females with an average age of 37.2 years (range, 26-74 years). The mechanism of injury was falling from height in 8 cases and traffic accident in 4 cases. The time from injury to operation was 4 to 11 days (mean, 6.8 days). According to the radial head, coronoid process, olecranon, and medial and lateral collateral ligament complexes injury situation, and based on Mason classification standard and O'Driscoll criteria, the classification standard of terrible triad of the elbow was improved. According to classification results, the approach was determined. The fracture reduction and fixation were performed and soft tissue was repaired. ResultsDehiscence of incision occurred in 1 case and was cured after dressing change; primary healing was obtained in the other patients. All the cases were followed up 19-35 months (mean, 21.6 months). The X-ray films showed fracture healing at 10-17 weeks (mean 12.8 weeks). At last follow-up, the mean flexion-extension arc of the elbow was 117.9° (range, 95-135°) and the mean forearm pronation and supination were 77.1° (range, 70-85°) and 62.5° (range, 45-75°). According to Mayo elbow performance score (MEPS), the results were excellent in 4 cases, good in 5 cases, and fair in 3 cases. One patient had valgus deformity of elbow who refused radial head replacement, and 5 cases had heterotopic ossification of the elbow on the X-ray films. ConclusionThe modified classification of the terrible triad of the elbow is simple and practical, based on the damage assessment of bony structures (radial head, coronoid process, and olecranon) and the soft tissue (medial and lateral collateral ligament complexes). The modified classification can be used effectively for guiding treatment decisions.