|
Axial close–up view of the spinal canal of
a cervical spinal specimen from an elderly adult who had no symptoms
from the cervical spine. The neck of the cadaver had been positioned
in moderate extension before it was frozen in situ. Compared to
SLIDE 4 (a spine frozen in flexion), the epidural and foraminal
veins in this specimen are completely emptied of blood. The
following components contribute to the central spinal canal
compromise: 1. retrolistheses of the upper vertebrae due to the
oblique inclination of the facet joints in the sagittal plane, 2.
thickening of the interlaminar ligamentum flavum (by relaxation
and/or volume redistribution) and 3. an osteophyte projecting
posteriorly from the lower endplate of the vertebra above. This
osteophyte exerts compression on the anterior tracts of the spinal
cord on the right side. In the foramina (root canals) the roots are
severely compressed because the (wedge–shaped) upper articular
process of the vertebra below intrudes into the foramen, pushing the
root against the uncovertebral joint osteophytes. The compression by
the uncovertebral spondylophyte is exerted on the anteriorly located
motor root, to a lesser extent on the dorsal sensory bundle. The
root lies in a groove and cannot yield to an anterior compression
(see SLIDE 5). |
©2000 Wolfgang Rauschning, M.D., Ph.D.
Professor of Clinical Anatomy
Academic
University Hospital
Department of Orthopaedic Surgery
Uppsala, Sweden
Reproduction without permission is prohibited
http://www.akademiska.se/
