The terrible triad of the elbow describes a dislocation of the elbow with associated fractures of the radial head and coronoid process of the ulna. The term'terrible triad’in this context was originally coined by Hotchkissin 1996 in reference to the inherent difficulty in treating these injuries and their historically poor outcomes. This type of injury is easy to cause missed diagnosis and misdiagnosis due to the lack of early understanding of its injury mechanism and fracture characteristics. There are still many patients with old terrible triad of the elbow combined with joint stiffness, whose elbow function is completely inadequate to meet daily needs.ObjectiveTo observe the surgical effect of old terrible triad of the elbow with joint stiffness.

FromFebruary2013 to June 2018, 7 patients (5 males and 2 females) of old terrible triad of the elbow combined with joint stiffness underwent surgical procedure. Their mean age was (45.14±15.79) years (18-61 years) . The clinical data and follow-up results were retrospectively analyzed. The mean time from injury to operation was (99.57±67.85) days (38-240 days) . There were 5 cases of right side and 2 cases of left side. Causes of injuries: 4 cases of fall damage, 2 cases of traffic accidents and 1 case of high fall injury. None of them showed the signs of neurological injury. According to Mason classification of radial head fracture, there were 1 case of typeⅠ, 3 cases of typeⅡ, 2 cases of typeⅢand 1 case of typeⅣ. According to Regan & Morrey classification of coronoid process fracture, there were 4 cases of typeⅠ, 2 cases of typeⅡ, and 1 case of typeⅢ. According to O’Driscoll classification of the tip fracture of ulna coronoid process, there were 4 cases of 1st subtype, 2 cases of 2nd subtype and 1 case of 3rd subtype. The elbow joint was subluxated in 5 cases and completely dislocated in 2 cases.The combination of medial and lateral incisions or the posterior midline approach combined with lateral incision were adopted to perform joint release, reconstruction of coronoid process and radial head and ligament repair. Treatment of radial head fracture: fracture fragment resection was performed in 1 case as the fragment accounted for approximately 10% of the articular surface, compression screw fixation was performed in 1 case with 2.0 mm countersunk screws, radial head replacement was performed in 2 cases, and 3 cases were left undone for good fracture position. Treatment of coronoid process: reconstruction procedure was performed in 2 cases with iliac bone, compression screw fixation was performed in 2 case with 3.0 mm countersunk screws, and 3 cases were left undone for good recovery. Treatment of ligament injury: ligament reconstruction was performed in 2 cases with partial brachial triceps tendon, and ligament repair was performed in 5 cases suture anchors. All of the patients were fixed with hinged external fixators to protect the bone and soft tissue. Standard functional training and early active exercise were conducted after operation.

After operation, all patients were followed up for an average of (13.28±4.34) months (10-23 months) . All the incisions obtained primary healing. The elbow function was evaluated using Mayo elbow performance score (MEPS) and Broberg-Morrey scoring systems. All fractures healed after operation without complications such as deformity, cannulated screw withdrawal, or cannulated screw breakage. At the last follow-up, the preoperative Mayo score was (42.86±11.13) points (25-55 points) , and the postoperative Mayo score was (85.29±2.75) points (80-89 points,P=0.000018) . The preoperative Broberg-Morrey score was (33.43±12.79) points (11-48 points) , and the postoperative Broberg-Morrey score was (85.57±2.23) points (83-89 points) . The preoperative VAS score was (6.43±0.98) points (5-8 points) , and the postoperative VAS score was (1.00±0.00) points (0-1 points,P=0.000006) . The preoperative extension range was 42.14°±10.35° (30°-60°) , and the postoperative extension range was 18.57°±8.02° (10°-30°,P=0.0581) . The preoperative flexion range was 75.71°±35.99° (20°-110°) , and the postoperative flexion range was 120.00°±8.16° (110°-130°,P=0.0272) . The preoperative pronation range was 24.29°±41.58° (0°-90°) , and the postoperative pronation range was 80.00°±5.77° (70°-90°,P=0.0126) . The preoperative supination range was 32.86°±43.09° (0°-90°) , and the postoperative supination range was 84.29°±15.12° (50°-90°,P=0.0154) .

It is necessary to pay attention to the early diagnosis of "terrible triad" of theelbow to prevent missed diagnosis and delayed treatment in clinical practice. Surgical treatment should be carried out for patients with old terrible triad of elbow combined with joint stiffness, and early functional exercise should be paid attention to as well, so as to obtain early and quick restoration of elbow joint function.