The biomechanical analysis of craniovertebral junction finite element model in atlas assimilation

To study the biomechanical change of the craniovertebral junction in conditions of atlas assimilation. Mimics software was used to process CT data of the craniovertebral junction in a health adult to obtain the three-dimensional reconstruction and the cloudy points of C1, C2 and part of the occipital bone. Then the cloudy points were imported into the Abaqus 6. 8 software to establish the occipito-atlantoaxial finite element model in normal structure. According to the established model in normal structure, the model in conditions of atlas assimilation was set by changing the model parameters. Both models of normal structure and atlas assimilation were loaded with 1. 5 N . m static moment to simulate four motions of flexion, extension, lateral bending and axial rotation respectively. The movement characteristics,joint stress force and ligament deformation was analyzed. Under 1. 5 N . m moment, in model of atlas assimilation the C1-C2 range of movement decreased from 13. 55° to 11.88° in flexion,increased from