Proximal Humerus Fractures Treated with Single or Dual-Plate Constructs: A Comparison of Clinical Outcomes.

INTRODUCTION: Proximal humerus fractures (PHF) are common injuries in the adult population. Open reduction internal fixation (ORIF) still represents the most common treatment for reconstructable injuries. Despite the continued prevalence of ORIF, studies have demonstrated fixation failure ranging from 11% to 18% and a reoperation rate of up to 27%.1 Dual plating is an emerging technique that has been noted to enhance fracture fixation. There is only one comparative study examining the outcomes of isolated locked plating versus dual plating. Therefore, our objective was to compare the effect of single and dual-plate constructs in operative PHFs with respect to complications and reoperations.

MATERIALS & METHODS: This was a single-institution, retrospective cohort study from 2010 to 2025. Patients ≥ 18 years of age with PHFs who underwent ORIF with either a single pre-contoured locking plate or with dual plate fixation with greater than six months follow up were included. Exclusion criteria included non-acute fractures (>6 weeks), isolated greater tuberosity fractures, pathologic fractures, and fractures with a head split. Postoperative data collected included demographics, injury mechanisms, comorbidities, fixation details, complications and reoperations.

RESULTS: 141 patients underwent ORIF for PHFs comprising 76 (single plate) and 65 (dual plate). The mean age of the overall cohort was 55.0 ± 15.4 with similar demographic profiles and comorbidities between groups. The mean postoperative follow-up was 14.0 ± 9.8 and 13.2 ± 6.5 months for the single and dual plate groups respectively. Fracture characteristics including medial calcar comminution, neck shaft angle, and Neer classification were not significantly different. Supplemental fixation with allograft occurred more frequently in the dual plate group (23.1% vs 3.9%, p<0.001). There was a significantly higher incidence of varus cutout (14.6 % vs 3.1%) and non-union (9.3% vs 0%) in the single plate group, p<0.05. The reoperation rate was higher in the single plating group (22.7% vs 5.4%), p<0.05. Regression analysis demonstrated high energy mechanisms increased the likelihood of reoperations (OR: 5.02, p=0.03). Finally, patients with dual plate fixation were less likely to require a reoperation (OR 0.16, p=0.02).

DISCUSSION / CONCLUSIONS: Proximal humerus fractures treated with ORIF utilizing dual-plated constructs are associated with less mechanical failures/reoperations and no increase in complications compared to single plate fixation. In particular, fractures secondary to high energy mechanisms may benefit with dual-plated constructs. Future clinical investigations should include a prospective randomized trial to further establish the role of dual or multiplanar plating fixation.