Cross-link is a risk factor for rod fracture at pedicle subtraction osteotomy site: A finite element study. (August 2019) - Park, Tae Hyun
Highlights: We aim to investigate whether cross-link is a risk factor for rod fracture at the pedicle subtraction osteotomy (PSO) site by using finite element model (FEM). The geometry and dimensions of FEM were obtained from a high-resolution computed tomography scan data of a 65 years old female patient with spinal sagittal imbalance. After PSO surgery, PVMS of the rod was significantly increased during flexion and extension at PSO site. With cross-link at PSO site, PVMS of rod was further significantly increased during flexion and extension. Abstract: Background: We aim to investigate using finite element model (FEM) whether the use of a cross-link is a risk factor for rod fracture at the pedicle subtraction osteotomy (PSO) site. Methods: The geometry and dimensions of the FEM were obtained from a high-resolution computed tomography scan data of a 65 years old female patient with spinal sagittal imbalance. The intact model was modified to place PSO on the L4 spine. A cross-link was placed at the PSO site. A multisegment spinal fusion model from L1 to the pelvis was used to compare and analyze the peak von Mises stress (PVMS) values of the implants. A compressive follower load of 400 N was added to the validated intact lumbar spinal model in the follower load path direction. Results: After PSO surgery, the PVMS of the rod was significantly increased during flexion and extension at the PSO site. With the cross-link at the PSO site, the PVMS of the rod was further significantly increased during flexion and extension. Conclusion: The cross-link at the PSO site increased the risk of rod facture, especially during flexion and extension stress.