The effect of bone fragment size and cerebrospinal fluid on spinal cord deformation during trauma: an ex vivo study.

Abstract

The purpose of the study was to assess the effect of CSF and the size of the impacting bone fragment area on spinal cord deformation during trauma. A transverse impact rig was used to produce repeated impacts on bovine and surrogate cord models. Tests were recorded with high-speed video and performed on specimens with and without CSF and/or dura mater and with 3 different impactor areas. The CSF layer was found to reduce the maximum cord deformation significantly. A 50% reduction in impact area significantly increased the maximum cord deformation by 20-30%. The surrogate model showed similar trends to the bovine model but with lower absolute deformation values. Cerebrospinal fluid protects the cord during impact by reducing its deformation. A smaller bone fragment impact area increases the deformation of the cord, in agreement with clinical results, where a higher impact energy-possibly giving rise to smaller fragments-results in a worse neurological deficit.