POSTERIOR DISLOCATION OF THE ELBOW WITH FRACTURES OF THE RADIAL HEAD AND CORONOID

Background: Posterior dislocation of the elbow with associated fractures of the radial head and the coronoid process of the ulna has been referred to as the "terrible triad of the elbow" because of the difficulties encountered in its management. However, there are few published reports on this injury. Methods: Eleven patients with this pattern of injury were evaluated after a minimum of two years. The radial head fracture had been repaired in five patients, and the radial head had been resected in four. None of the coronoid fractures had been repaired, and the lateral collateral ligament had been repaired in only three patients. All eleven patients returned for clinical examination, functional evaluation, and radiographs. Results: Seven elbows redislocated in a splint after manipulative reduction. Five, including all four treated with resection of the radial head, redislocated after operative treatment. At the time of final follow-up, three patients were considered to have a failure of the initial treatment. One of them had recurrent instability, which was treated with a total elbow arthroplasty after multiple unsuccessful operations; one had severe arthrosis and instability resembling neuropathic arthropathy; and one had an elbow flexion contracture and proximal radioulnar synostosis requiring reconstructive surgery. The remaining eight patients, who were evaluated at an average of seven years after injury, had an average of 92° (range, 40° to 130°) of ulnohumeral motion and 126° (range, 40° to 170°) of forearm rotation. The average Broberg and Morrey functional score was 76 points (range, 34 to 98 points), with two results rated as excellent, two rated as good, three rated as fair, and one rated as poor. Overall, the result of treatment was rated as unsatisfactory for seven of the eleven patients. All four patients with a satisfactory result had retained the radial head, and two had undergone repair of the lateral collateral ligament. Seven of the ten patients who had retained the native elbow had radiographic signs of advanced ulnohumeral arthrosis. Conclusions: Elbow fracture-dislocations that involve a fracture of the coronoid process in addition to a fracture of the radial head are very unstable and prone to numerous complications. Identification of the coronoid fracture is therefore important, and computed tomography should be used if there is uncertainty. With operative treatment, the surgeon should attempt to restore stability by providing radiocapitellar contact (preserving the radial head when possible and replacing it with a prosthesis otherwise), repairing the lateral collateral ligament, and perhaps performing internal fixation of the coronoid fracture.