Purpose <p>To evaluate the outcomes of complex intra-articular fractures of the distal humerus (AO13-C3) in mid-term follow-up and determine possible risk factors that lead to a poor outcome.</p> Methods <p>69 patients (58.2 ±15.2 years, 49.3% women) who underwent surgery for complex intra-articular distal humerus fractures (AO 13-C3) using dual-plate osteosynthesis were included. Follow-up assessment was performed after a mean of 4.8 ±2.3 years. Post-operative clinical outcome (range of motion, heterotopic ossification, osteoarthritis, etc.) as well as established elbow scores (Mayo Elbow Performance Score (MEPS), Oxford Elbow Score (OES), Disabilities of the Arm, Shoulder and Hand score (DASH)) were analysed.</p> Results <p>The range of motion for flexion and extension was 111.3° ±24.7° and for pro- and supination 175.9° ±9.5°. The recorded outcome scores showed a MEPS of 90.1 ±16.6, an OES of 38.3 ±10.5, and a DASH score of 18 ±20.4. Post-operative complications and surgical revisions occurred in 29% of the patients. BMI ≥30&#xa0;kg/m² was associated with up to a nine-fold increased risk of poor post-operative outcome. Even in elderly patients (≥80 years), good post-operative results have been achieved in most cases (MEPS 87.5 ±28.2).</p> Conclusion <p>Favourable post-operative results can be achieved in most C3 distal humerus fractures treated with osteosynthetic reconstruction. The surgical approach does not seem to be critical for the post-operative outcome and should be chosen according to the fracture morphology. Even in older patients, good functional outcomes can be achieved in most cases. However, the attending surgeon should be aware of potential risk factors for a poor post-operative outcome, such as an increased BMI.</p>