PEEK颈椎融合器的拓扑优化设计

The three-dimensional topological optimization of cervical interbody fusion cage was developed by the finite element method to enhance the fusion rate of the cervical interbody cage. The finite element (FE) model of C3-C7 segments was constructed and validated. The fusion FE model was developed by inserting the cage into the C5-C6 disc space and internal fixation used anterior plate-screw system. The initial structures of cages made of polyether ether ketone (PEEK) were set up into two types of elliptic cage and box. Topological optimization and weighted compliance optimization were developed under single and multiple loading conditions. The structural configuration analysis of the cage was carried out after two times of topological optimization. The results showed that the optimal structure of the cage is annular, and the materials of the cage are concentrated in the back and both sides; the cage is optimized for multi-pore shape and single large-pore shape when the volume fraction is set to 50% and 30%, respectively, and the former has more contact area with the endplate than the latter; the optimized cage increases the stress on the internal bone graft by reducing its own stress under loading.In this study, the optimal PEEK cage was designed by topological and weighted compliance optimization method, which was not affected by the change of initial structures of cage.It can effectively reduce the stress shielding and increase the stress stimulation of internal bone graft, which will help to promote the cervical fusion.