[Construction of three-dimensional finite element model and biomechanical study on patient with with cervical...

To establish a three-dimensional finite element model (FEM) of the neck, to analyze the differences in neck biomechanics between patient with cervical spondylotic myelopathy (CSM) and healthy subject and to provide biomechanics basis for the pathogenesis of CSM.
 Methods: A patient with CSM was enrolled in a mechanical simulation experiment. Three-dimensional CT scan was performed, and three-dimensional FEM of the neck was constructed. A heathy subject was selected as a control according to the patient's age, gender, height, and weight. Three-dimensional FEM was used to compare the stress differences in the vertebral body, intervertebral disc, ligament and spinal cord under the normal stress of the cervical spine and the maximum stress of the posterior reclining motion.
 Results: Successfully constructed FEM model of CSM patient and control, and performed mechanical analysis, the most obvious difference in cervical vertebral body force was at C5-C6 segment in CSM patients. The maximum stress site of control and patient was at the anterior edge of the vertebral body. The maximum stress of the vertebral body in the CSM patient was less than that of the control. The stress distribution of the intervertebral disc was irregular in the CSM patient, and the maximum stress was concentrated on both sides of the posterior edge of the intervertebral disc. The stress distribution of the ligaments of the CSM patient was uneven. The maximum stress was in the posterior longitudinal ligament. The range of neck movement in extension of the CSM patient was restricted.
 Conclusion: Compared with the healthy subject, the balance of the vertebral body, intervertebral disc, ligament and limited range of motion of the CSM patient has been changed, which may be related to the mechanical pathogenesis of cervical spondylotic myelopathy.