Morphology-guided approach selection for AO/OTA 13-C3 distal humeral fractures: a comparative study of the flip-triceps dislocation approach versus olecranon osteotomy

The optimal surgical approach for AO/OTA 13-C3 distal humeral fractures remains debated. This study compared the flip-triceps dislocation (FTD) approach with the olecranon osteotomy (OO) approach and evaluated whether fracture morphology, classified as posterior articular displacement (PAD)-type or non-PAD-type fractures, is associated with differences in clinical outcomes between the two approaches. Thirty-seven patients with AO/OTA 13-C3 distal humeral fractures were retrospectively reviewed, including 18 treated with OO and 19 with FTD. Fractures were classified as PAD-type (n = 20) or non-PAD-type (n =17) based on preoperative three-dimensional CT. Operative time, intraoperative blood loss, flexion–extension arc, extension deficit, MEPS, DASH score, and elbow stiffness were compared between groups and subgroups. The mean follow-up duration was 18.6 ± 5.1 months. The FTD group demonstrated a significantly shorter operative time (124.6 ± 24.8 vs. 156.4 ± 29.7 min) and lower intraoperative blood loss (192.6 ± 54.2 vs. 278.3 ± 72.8 mL) than the OO group (both P < 0.001). At final follow-up, overall flexion–extension arc, extension deficit, MEPS, and DASH scores were comparable between groups. In PAD-type fractures, the FTD group achieved significantly lower extension deficit than the OO group (4.8±3.2° vs. 10.2±5.4°, P =0.018), whereas no difference was observed in non-PAD-type fractures. The FTD approach was associated with shorter operative time and less intraoperative blood loss than the OO approach while achieving no statistically significant differences in overall functional outcomes. In PAD-type fractures, FTD was associated with superior terminal extension, suggesting that fracture morphology may inform surgical approach selection.