Document Type


Publication Date



Objectives: Recent studies report nonunion rates of up to fifteen percent for nonoperative treatment of displaced, comminuted, or shortened midshaft clavicle fractures. Additionally, authors suggest operative treatment of these comminuted displaced midshaft clavicle fractures leads to a more satisfactory clinical outcome. Biomechanically, clavicle fracture plate fixation has been analyzed for locking versus non-locking screw use, but little evidence on hybrid screw use exists. We hypothesized that fixation of a comminuted midshaft clavicle fracture model with a pre-contoured hybrid screw-plate construct would increase stiffness and load-to-failure compared to a non-locking screw construct. Methods: Fourteen matched pairs of fresh frozen cadaveric clavicles were randomized into two groups: hybrid screw fixation (n=7 pairs) and non-locking screw fixation (n=7 pairs). One clavicle from each pair was randomly selected to receive a 1cm midshaft gap osteotomy and plate fixation, while the remaining clavicle was tested as the intact control. The clavicles were tested through four-point bending to determine stiffness and load-to-failure. Results: The hybrid construct was seventeen percent more stiff compared to the non-locked construct, although this did not reach statistical significance (p=0.09). The non-locked construct was significantly less stiff than the intact clavicle, whereas there was no significant difference in stiffness between the hybrid construct and the intact clavicle. Load-to-failure was not significantly different between the hybrid and nonlocked constructs. Conclusion: There was a trend towards higher stiffness of the hybrid construct compared to the non-locked construct. A similar study with more statistical power is needed to fully elicit the true differences in stiffness and load-to-failure between the two constructs. Level of Evidence: Basic Science Study – Biomechanical Level I


© The author(s) 2014. Published with open access at