Surgical treatment of coronal shear fractures of the distal humerus with an intact lateral epicondyle by the lateral combined approach

Background: Coronal shear fractures of the distal humerus are not only rare and prone to misdiagnosis, but their surgical treatment can be challenging. We aimed to investigate the feasibility of exposing distal humeral coronal shear fractures with a combined lateral approach that preserves the extensors and lateral ulnar collateral ligament (LUCL) and to analyze the clinical efficacy of open reduction and internal fixation in the treatment of these injuries. Methods: We included 45 patients who sustained coronal shear fractures of the distal humerus with the lateral epicondyle intact and were treated with open reduction and internal fixation from January 2013 to August 2020. The fractures were exposed by the lateral combined approach in which the tendons involving the common extensor, the extensor carpi ulnaris, and the LUCL were preserved. Two observation windows were formed anterior to and posterior to these tendons and the LUCL was used to achieve fracture reduction. Countersunk screws, with or without a plate placed on the posterior lateral condyle, were used to fix the fragments. The functional outcomes of these patients were reviewed and assessed with physical and radiographic examinations, range of motion measurements, and self-evaluation Mayo Elbow Performance Index and the Disabilities of the Arm, Shoulder, and Hand scores. Results: In total, 40 patients were followed up with for over 1 year and were included in the final analysis. The mean follow-up duration was 42 +/- 30 months (range, 12-107 months). The patients' mean age was 42 years (range, 14-74 years). According to the Dubberley Classification, there were 15 type I, 17 type II, and 8 type III fractures. At the final follow-up, the mean flexion-extension arc was 131 degrees (range, 65-150) and mean pronation and supination was 73 degrees (range, 45-80) and 71 degrees (range, 40-80), respectively. The mean Mayo Elbow Performance Index score was 88 (range, 61-97) points; the results were excellent in 21, good in 13, fair in 4, and poor in 2 patients. The mean Disabilities of the Arm, Shoulder, and Hand score was 11 (range, 0-42) points. Neither functional score nor range of movement was associated with age, sex, fracture type, injury type, or surgical timing. Conclusion: Reduction and stable fixation with internal fixation for coronal shear fractures of the distal humerus can be achieved by the lateral combined approach. Early functional mobilization allows for satisfactory restoration of elbow function. Level of evidence: Level IV; Case Series; Treatment Study (c) 2024 The Author(s). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/