Clinical comparison of single posterolateral plate with medial-cannulated-screw fixation and double-plate fixation for extra-articular distal humerus fractures

BACKGROUND: Double-plate fixation is the gold standard for extra-articular distal humerus fractures, but it carries a substantial risk of postoperative ulnar neuropathy. Fixation using a single posterolateral plate with a medial cannulated screw may reduce ulnar neuropathy while maintaining fracture stability. This study aimed to compare the clinical outcomes of single-plate-with-medial-screw fixation versus double-plate fixation for extra-articular distal humerus fractures. MATERIALS AND METHODS: Fifty-six patients who underwent surgery for extra-articular distal humerus fractures (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association [AO/OTA] classification A2 or A3) between January 2018 and August 2024 were divided into a double-plate group and a single-plate-with-medial-screw group. We conducted a retrospective, nonrandomized comparative study. The double-plate fixation was used in 30 patients from January 2018 to October 2021, while the single-plate fixation with a medial screw was used in 26 patients from November 2021 to August 2024. All surgeries were performed using a posterior paratricipital approach. Bony union, radiographic healing, and loss of reduction were evaluated. Postoperative pain scores (visual analog scale at 2 days after the operation), operative time (minutes), elbow range of motion, elbow function (Mayo Elbow Performance Score [MEPS]), and the presence of postoperative ulnar neuropathy were compared between the two groups. RESULTS: The double-plate fixation and single-plate fixation with a medial screw were performed in 30 and 26 patients, respectively. The mean age was 54.8 ± 19 (range, 17-85) years, and the mean follow-up duration was 18.2 ± 6.5 (range, 12-38) months. All fractures achieved solid osseous union at final follow-up. No significant differences were observed between the groups in terms of postoperative pain score, range of motion, and MEPS (all p > 0.05). However, the operative time was shorter for the single-plate-with-medial-screw group than that for the double-plate group (112.5 ± 25.7 versus 172.2 ± 35.2 min, p < 0.05), and the operative time was significantly associated with the fixation method (p < 0.05). In addition, postoperative ulnar neuropathy occurred less frequently with the single-plate-with-medial-screw group than with the double-plate group (8% versus 37%, p = 0.013). CONCLUSIONS: Both double-plate and single-plate-with-medial-screw fixation showed comparable union rates and functional outcomes in extra-articular distal humerus fractures. However, single-plate fixation with a medial screw required a shorter operative time and was associated with a lower incidence of postoperative ulnar neuropathy than double-plate fixation. Level of evidence Level III, retrospective comparative study.