Effects of a contusion load on spinal cord with different curvatures.

The cervical spine injury is a complicated procedure in the combination of different injury loads and postures. The aim of this study is to investigate the injury mechanism considering different types of cervical curvatures subjected to contusion loads. A finite element model of a cervical spinal cord was constructed. Gray matter, white matter and pia matter were modeled and hyperelastic material properties were assigned. Convergence analysis and validation analysis were carried out. The model was simulated in 3 different spinal curvatures and loaded by 2 directions with 4 compression degrees. The maximum von Mises stress in the whole model was concentrated in the pia matter in all loading cases. When investigating spinal cord injury, the pia matter must be considered. For all three curvatures, the stress in the gray matter and white matter was higher in front-to-back loading condition than that in back-to-front loading condition. The front-to-back impact may cause a larger damage. A back-to-front load damaged the structure around the central canal and a front-to-back contusion load damaged the anterior horn of the spinal cord at most time. From the view of the maximum stress, the lordotic curvature did not show significant buffering effect. However, the pathological curvature had large areas affected and the lordotic curvature showed some benefits to some degree from the view of stress distribution.