Surgical Treatment of Adams Type IV Anterolateral Fracture of the Ulna Coronoid Process

Anterolateral coronal fractures are so rare that the mechanism of injury, the type of combined fracture and ligament injury, and the optimal treatment are unknown. To study the outcome of surgical treatments for anterolateral (AL) fracture of the ulna coronoid process (Adams Type IV) and summarize the characteristics of this type of fracture and to guide clinical applications.

From February 2015 to April 2021, 32 patients were included in the study. All patients had standard radiography with anteroposterior and lateral views, computed tomography, and intraoperative fluoroscopy. All patients were treated surgically. Surgery-related information, including surgical approach, operation duration, blood loss, and repairing the lateral collateral ligament and the medial collateral ligament integrity, were recorded. The patient's clinical details, such as the final range of motion (ROM), the Broberg-Morrey scores and the visual analogue scale (VAS) at the last follow-up, were described. The chi-square test or Fisher's exact test was used for statistical analysis.

We divided patients into two groups according to the anterolateral coronoid fracture morphology. In the intact group, 20 patients with an intact anterolateral coronoid fracture fragment. In the comminuted group, 12 patients with comminuted anterolateral coronoid fracture fragments extended the less sigmoid notch of the ulna. There was no difference in age, sex, total incision length, follow-up duration, and recovery with rehabilitation among the two groups (all Ps >0.05). The other follow-up outcomes, such as elbow ROM (Flexion, Extension, Posterior rotation, Anterior rotation), VAS score, or Broberg-Morrey scores, were not different between the two groups (all Ps >0.05). Both groups achieved relatively satisfactory clinical outcomes, and the Broberg-Morrey score and index excellence rate reached 84.38%. There is a statistical difference in the history of elbow dislocation (P = 0.017), radial head fracture type (P = 0.041), operation duration (P = 0.014) and blood loss at operation (P = 0.029) between the two groups. Cannulated screws, anchors, and sutures were used as point fixation in the coronoid process of the ulna. There was a statistical difference between the two groups in the choice of internal fixation (P = 0.020).

For anterolateral ulnar coronoid fractures with different degrees of comminution, effective and reliable surgical treatment can achieve better results and fewer complications.