Abstract

Numerical analysis of compressive neck injuries produced by the crown impact to the head

Author(s): H.B.Chen, L.Y.Zhang, J.H.Zhou, S.Tang, L.He, J.Zhang

Traffic trauma data indicated that neck injuries became the fifth most important injury category (after head, face, chest and abdomen). A vertical compression from the crown impact to the head could be a very common neck loading mode during rollovers. The purpose of this paper is to summarize a numerical analysis of compressive neck injuries produced by the crown impact to the head. In this paper, a validated head-neck complex FE model was used to simulate those cadaver compression tests, and the compression and facet strain from all three loading conditions (flexion, stiff and extension) were calculated for three impact velocities (3.25 m/s, 5.25 m/s, 7.25 m/s). Comparing all the cases, it was suggested that: â‘  A high compressive load can be transmitted from the head to the neck only if the cervical spine was straight. Especially, at higher crown-impact velocities the skull fractured and was still able to contribute a higher force on the C7 vertebral body, making the C6-C7 and C7-T1 region a potential injury site. â‘¡ When the neck is in the flexed or extended position initially, the C4-C5 intervertebral disc becomes a typical rotation centre so that C3-C4 or C4-C5 disc is less vulnerable to injury. â‘¢ The C2-C3 facet is likely to be compressed most in both local x-axis (along the facet joint surface) and z-axis (normal to the facet joint surface) and the role of compression force with more sliding in cervical facet surface may be an important causal mechanism leading to facet failure in compressive neck injuries.