The upper cervical spine comprising the base of the skull, first cervical vertebra (C1) and second cervical vertebra (C2) is one of the most complex joints in the human spine. In low severity automotive crash scenarios, ligament distraction has been implicated as a source of whiplash pain, while at higher impact severities vertebral fracture and distraction can lead to serious or fatal injuries. The objective of this study was to investigate kinematic response and predicted injury of the upper cervical spine using a 50th percentile male numerical model including detailed representations of the ligaments, vertebral bodies and joints. The model was evaluated in four modes of loading. In general, the model was able to predict failure loads and distractions for flexion, extension, tension and axial rotation in good agreement with the available experimental data. The failure load in tension was higher than the experimental average likely due to the younger ligament properties used, which were stiffer and stronger than properties from an older population.
Keywords:
Upper cervical spine, injury, finite element model