Abstract:[Objective] To compare the clinical efficacy of lateral approach (LA) versus olecranon osteotomy approach (OOA) for open reduction and internal fixation (ORIF) of Dubberley type II-IIIB humeral capitellum fractures. [Methods] A retrospective study was con- ducted on 39 patients who underwent ORIF for Dubberley type II-IIIB capitellum fractures in our hospital from December 2014 to Decem- ber 2019. According to the results of preoperative doctor-patient communication, 21 patients had ORIF performed by the LA, while the re- maining 18 patients were by the OOA. The perioperative, follow-up and imaging data of the two groups were compared. [Results] All the pa- tients in both groups had ORIF finished smoothly without serious complications, such as neurovascular injury. The LA group was signifi- cantly superior to the OOA group in terms of incision length, operation time and intraoperative blood loss (P<0.05) , while the OOA group proved significantly superior to the LA group in terms of intraoperatively fluoroscopic times and time to resume active motion postoperative- ly (P<0.05) , despite of no a statistically significant difference between them in term of hospital stay (P>0.05) . With time of follow-up peri- od lasted for (18.74±2.65) months on an average, the VAS scores decreased significantly (P<0.05) , whereas the elbow flexion extension range of motion (ROM) and Mayo Elbow Performance Score (MEPS) increased significantly in both groups (P<0.05) . However, the OOA group proved significantly superior to the LA group in terms of VAS and MEPS scores, as well as elbow flexion-extension ROM one month postoperatively (P<0.05) , whereas which became not statistically significant between the two groups at 6 and 12 months postoperatively (P> 0.05) . Radiographically, the OOA group also proved significantly superior to the LA group in terms of fracture reduction quality and frac- ture healing time (P<0.05) . [Conclusions] Compared with the LA, the OOA used for ORIF of Dubberley type II-IIIB fractures does facili- tate fracture reduction and has more stable internal fixation, which allow active elbow motion earlier to achieve better clinical outcomes.