Sagittal section through a degenerated
lower lumbar spine of a 68–year–old man with no history of back pain
or radiculopathy. At L5–S1 there is complete resorption of the
intervertebral disc and stable fusion of the cartilaginous endplates
that are bordered by a band of subchondral endplate sclerosis.
Posteriorly the hard and dark outer annular layers are extruded into
the midzone or pedicle portion of the root canal in which the
relatively small dorsal root ganglion snugly follows the pedicle.
The radicular artery is very small and that, despite the complete
loss of segmental height, the segmental veins are not entirely
collapsed. The total disc resorption also entails a severe
shortening in the posterior elements as demonstrated here by the
axial shortening subluxation of the facet joint. Its vertical,
apparently less loaded facet, carries macroscopically normal hyaline
cartilage whereas the tip of the upper articular process erodes into
the inferior aspect of the pars interarticularis of L5. There is
osteoarthrosis with osteophyte formation of the tip of the superior
articular process. |
©2000 Wolfgang Rauschning, M.D., Ph.D.
Professor of Clinical Anatomy
Department of Orthopaedic Surgery
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