Highly extensile approach for comminuted ulna coronoid process fractures with mini-plate fixation: a case series of 31 patients.

Background: For the treatment of coronoid process fractures, medial, lateral, anterior, anteromedial, and posterior approaches have been increasingly reported; however, there is no general consensus on the method of fixation of coronal fractures. Here, we present a highly-extensile minimally invasive approach to treat coronoid process fractures using a mini-plate that can achieve anatomic reduction, stable fixation, and anterior capsular repair. Further, the study aimed to determine the complication rate of the anterior minimally invasive approach and to evaluate functional and clinical patient-reported outcomes during follow-up.

Methods: Thirty-one patients diagnosed with coronoid fractures accompanied with a "terrible triad" or posteromedial rotational instability between April 2012 and October 2018 were included in the analysis. Anatomical reduction and mini-plate fixation of coronoid fractures were performed using an anterior minimally invasive approach. Patient-reported outcomes were evaluated using the Mayo Elbow Performance Index (MEPI) score, range of motion (ROM), and the visual analog score (VAS). The time of fracture healing and complications were recorded.

Results: The mean follow-up time was 26.7 months (range, 14-60 months). The average time to radiological union was 3.6 ± 1.3 months. During the follow-up period, the average elbow extension was 6.8 ± 2.9° while the average flexion was 129.6 ± 4.6°. According to Morrey's criteria, 26 (81%) elbows achieved a normal desired ROM. At the last follow-up, the mean MEPI score was 98 ± 3.3 points. There were no instances of elbow instability, elbow joint stiffness, subluxation or dislocation, infection, blood vessel complications, or nerve palsy. Overall, 10 elbows (31%) experienced heterotopic ossification.

Conclusion: An anterior minimally invasive approach allows satisfactory fixation of coronoid fractures while reducing incision complications due to over-dissection of soft tissue injuries. In addition, this incision does not compromise the soft tissue stability of the elbow joint and allows the patient a more rapid return to rehabilitation exercises.