Background: To improve the primary operative treatment of complex olecranon fractures we searched for new conclusive parameters. We hypothesized that the intermediate fragment plays a critical role for precise restoration of the trochlear notch contour and good outcome of initial operative treatment.

Methods: 58 patients (26 female, 32 male; mean age 55 years) with multi-fragmentary olecranon fracture were identified in a seven-year-period from trauma unit files at two European Level 1 trauma institutions. Retrospective review of all operative reports and radiographs/computed tomography scans identified patients with an intermediate fragment.

Results: 28 patients were treated with stable internal fixation using figure-of-eight tension-band wire fixation and 30 patients using posterior plate osteosynthesis with and without intramedullary screw. An intermediate fragment was seen in 36 patients (62 %). In 17 of these 36 patients (47 %), the intermediate fragment was described in operative report. Twelve of these patients (71 %) were treated with single posterior plate with/without an intramedullary screw, and five patients (29 %) with figure-of-eight tension-band wire fixation.

Conclusion: Fracture analysis identified an intermediate fracture fragment in the majority of patients with complex olecranon fractures. In diagnostic work up a CT scan should be used to assess the fracture pattern and to detect an intermediate fragment. This study suggests that identification, desimpaction and anatomic reduction of the intermediate fragment are critical preconditions for anatomic restoration of the trochlear notch and good functional results. Precise description of the fracture pattern including presence of an intermediate fragment in the operative report is recommended.