Proximal humerus fractures (PHFs): comparison of functional outcome 1 year after minimally invasive plate osteosynthesis (MIPO) versus open reduction internal fixation (ORIF)

Purpose: Osteosynthetic treatment strategies of PHFs include MIPO or ORIF techniques. The aim of this study was to compare the 1 year outcome following either technique in type B PHFs. Methods: This study was designed as a retrospective cohort study of patients treated at one academic Level 1 trauma center. Patients from 2009 to 2019 who required surgical treatment of a type B PHF were eligible to be included in this study. Patients with A- or C-type fractures or patients requiring arthroplasty were excluded. All patients were treated with Proximal Humerus Interlocking System (PHILOS) and stratified according the approach into Group MIPO or Group ORIF. Outcome measures include local complications that occurred during hospitalization, nonunion after 12 months, and range of motion after 1 year follow-up. Results: This study included 149 (75.3%) patients in Group ORIF, and 49 (24.7%) in Group MIPO. The fracture morphology and concomitant injuries were comparable amongst these groups. When compared with Group MIPO, Group ORIF had a 2.6 (95% CI 0.6–11.7) higher risk of suffering from local complications. The rate of postoperative nerve lesions was comparable (OR 0.9, 95% CI 0.1–9.7) as was the rate of soft tissue complications (OR 2.0, 95% CI 0.2–17.2). The risk for nonunion was 4.5 times higher (95% 1.1–19.5) in Group ORIF when compared with Group MIPO. Group MIPO had a higher chance of flexion above 90° (OR 8.2, 95% CI 2.5–27.7). Conclusion: This study provides indications that patients following surgical treatment of PHFs in MIPO technique might have favourable outcome. Large-scale and high-quality studies are warranted to confirm these results