Impact of the surgical strategy on the incidence of C5 nerve root palsy in decompressive cervical surgery - Fig 4

<p>Illustration of the cervical spinal nerve roots exiting the spinal cord (left). The right side schematically depicts the angle, including the superior and inferior rootlets of the individual nerve root, emphasizing the distinct nerve root exit of C5 as formerly described by Hung <i>et al</i>. and Alleyne <i>et al</i>. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0188338#pone.0188338.ref019" target="_blank">19</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0188338#pone.0188338.ref020" target="_blank">20</a>]. Sagittal T2w magnetic resonance imaging of the cervical spine before (B) and after (C) dorsal decompression. This image highlights the dorsal shift of the spinal cord due to decompression. Figure D and E schematically explain the postulated hypothesis on the pathophysiological basis of C5 nerve root palsy. A slowly established ventral stenosis (D) results in a dorsal shift of the myelon, leading to a stretched C5 nerve root (blue), as depicted in the axial view. Ventral decompression through ACDF consecutively leads to a ventral shift of the spinal cord with kinking of the nerve root. A dorsal stenosis (E) represents an analogous situation with dorsal shifting of the spinal cord after laminectomy and fusion, as suggested by the screws. Additional information on the pathophysiological basis can be found in supporting information <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0188338#pone.0188338.s001" target="_blank">S1 Video</a>.</p>