Surgical management of complex humeral shaft fractures (AO/OTA 12-C): A multicenter comparison of open plating, MIPO, and intramedullary nailing.

BACKGROUND: The optimal fixation strategy for complex humeral shaft fractures, especially those with severe comminution, remains controversial. This study compared clinical and radiological outcomes after open reduction and internal fixation (ORIF), minimally invasive plate osteosynthesis (MIPO), or intramedullary (IM) nailing for AO/OTA type 12-C humeral shaft fractures. PATIENTS AND METHODS: This multicenter retrospective comparative study included 75 adults with AO/OTA type 12-C humeral shaft fractures treated surgically between 2015 and 2023. Patients were grouped by the fixation method, as follows: ORIF (n = 26), MIPO (n = 30), and IM nailing (n = 19). Radiological outcomes and complications were recorded. Functional outcomes were assessed using the Disabilities of the Arm, Shoulder, and Hand (DASH) score, Mayo Elbow Performance Score (MEPS), and joint range of motion (ROM). RESULTS: Baseline demographics and fracture characteristics did not differ significantly among the groups; however, IM nailing had numerically higher polytrauma rates and median Injury Severity Score. The operative time was significantly longer with ORIF (143.0 vs. 102.1 vs. 95.5 min; P < 0.001), and the intraoperative blood loss was greater with ORIF than with MIPO or IM nailing (292.0 vs. 196.2 vs. 182.3 mL; P < 0.001). Radiographic union occurred in 92.3%, 93.3%, and 84.2% of the patients after ORIF, MIPO, and IM nailing, respectively (P = 0.53). Postoperative radial nerve palsy occurred in five patients (ORIF, 3; MIPO, 1; IM nailing, 1); all but one resolved within 6 months. Nonunion, malunion, and reoperation rates differed only numerically. Functional outcomes, including DASH score (P = 0.11), MEPS (P = 0.18), elbow ROM (P = 0.09), shoulder forward flexion (P = 0.264), and shoulder abduction (P = 0.228), did not differ significantly across the fixation methods. CONCLUSION: All three techniques achieved acceptable union and functional outcomes in AO/OTA type 12-C humeral shaft fractures. MIPO showed a numerically favorable trend toward fewer complications and less surgical invasiveness than ORIF. IM nailing showed numerical trends toward higher nonunion and malunion rates and slightly lower shoulder mobility, whereas ORIF required longer operative times and demonstrated greater intraoperative blood loss. Considering the retrospective design, surgeon-selected allocation, and limited statistical power, these findings warrant caution. The fixation strategy should be tailored to the fracture morphology, soft-tissue condition, patient factors, and surgeon experience.