Abstract:

BACKGROUND: The internal forces analysis of clavicle is significant to the clinical fixation of fracture. However, the finite element method has disadvantages in obtaining the distribution of the internal forces due to limitations of element shape, load mode, and boundary condition.
OBJECTIVE: According to the physiological structures of acromioclavicular joint, the internal force distribution of acromioclavicular joint was analyzed using relatively simple and visualized mechanical method.
METHODS: According to cross-section, clavicle was simplified as a dimensional curved beam which was subject to certain loads. The internal forces on the cross section of clavicle were solved by the force-balance equations and the relationship between the internal forces, and the loads act on the ends of clavicle is discussed. The ratio of bending moment to torsion moment along the clavicle was analyzed.
RESULTS AND CONCLUSION: Calculation results matched clinical experience and finite element analysis. The ratio of bending moment to torsion moment shows that the cross section of the midspan region of clavicle is deformed zone of bending and torsion. Therefore, the fracture fixation in the midspan region of clavicle should consider the resistances including not only bending moment but also torsion moment.