Xuexiao Ma1, Xianbo Peng1, Hongfei Xiang1, Yan Zhang1, Guoqing Zhang1, Bohua Chen2. 1. Department of Orthopaedic Surgery, the Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China. 2. Department of Orthopaedic Surgery, the Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China. Email: bhchen@hotmail.com.
Abstract
BACKGROUND: The objective of this study was to use three-dimensional finite element (FE) models to analyze the stability and the biomechanics of two upper cervical fixation methods: the C2 intralaminar screw method and the C2 pedicle screw method. METHODS: From computed tomography images, a nonlinear three-dimensional FE model from C0 (occiput) to C3 was developed with anatomic detail. The C2 intralaminar screw and the C2 pedicle screw systems were added to the model, in parallel to establish the interlaminar model and the pedicle model. The two models were operated with all possible states of motion and physiological loads to simulate normal movement. RESULTS: Both the C2 intralaminar screw method and the C2 pedicle screw method significantly reduced motion compared with the intact model. There were no statistically significant differences between the two methods. The Von Mises stresses of the internal and external laminar walls were similar between the two methods. Stability was also similar. CONCLUSIONS: The C2 intralaminar screw method can complement but cannot completely replace the C2 pedicle screw method. Clinicians would need to assess and decide which approach to adopt for the best therapeutic effect.
BACKGROUND: The objective of this study was to use three-dimensional finite element (FE) models to analyze the stability and the biomechanics of two upper cervical fixation methods: the C2 intralaminar screw method and the C2 pedicle screw method. METHODS: From computed tomography images, a nonlinear three-dimensional FE model from C0 (occiput) to C3 was developed with anatomic detail. The C2 intralaminar screw and the C2 pedicle screw systems were added to the model, in parallel to establish the interlaminar model and the pedicle model. The two models were operated with all possible states of motion and physiological loads to simulate normal movement. RESULTS: Both the C2 intralaminar screw method and the C2 pedicle screw method significantly reduced motion compared with the intact model. There were no statistically significant differences between the two methods. The Von Mises stresses of the internal and external laminar walls were similar between the two methods. Stability was also similar. CONCLUSIONS: The C2 intralaminar screw method can complement but cannot completely replace the C2 pedicle screw method. Clinicians would need to assess and decide which approach to adopt for the best therapeutic effect.