There is no uniform approach to the management of lateral clavicle fractures. Recent studies have investigated additive coracoclavicular (CC) augmentation as a treatment option; however, it is unclear whether it is superior to conventional locking plate osteosynthesis. We carried out a retrospective analysis of 40 patients with lateral clavicle fracture (Neer type IIb) who were treated between 2014 and 2017 with either a hybrid locking plate osteosynthesis/additive arthroscopy-assisted CC augmentation (HP) procedure or a locking plate osteosynthesis only (PO) approach to determine which strategy was more effective. At follow-up, subjective shoulder value, age- and sex-adjusted Constant-Murley score, Taft (TF) score, American Shoulder and Elbow score, Nottingham clavicle score, and Visual Analogue Scale score were compared between patient groups. A radiologic evaluation was also conducted. A total of 14/17 patients (83%; 9 male/5 female, mean age: 43 ± 15years) were followed up in the PO group. The mean follow-up time was 29 ± 12.4months. In the HP group, 17/23 patients (74%; 9 male/8 female, mean age: 43 ± 17years) were followed up, with a mean follow-up time of 18 ± 7.1months. There were no significant differences in clinical parameters between the HP and PO groups; notably, the shoulder girdle-specific TF score was comparable in the 2 groups (HP: 11.3 ± 1.1 points and PO: 10.9 ± 0.9 points). In the HP group, additional pathologies were identified and arthroscopically treated in 35% of cases. Radiologic examination revealed a significant difference between pre- and postoperative CC distance in the HP group (P = 0.001). Additive CC augmentation in combination with locking plate osteosynthesis seems to improve the vertical stability and reduces the revision rate in patients with a lateral clavicle fracture. Furthermore, an arthroscopy-assisted procedure allows for an intraoperative detection and single-step treatment of accompanying intraarticular pathologies.