Variations in the lumbosacral ligament and associated changes in the lumbosacral region resulting in compression of the fifth dorsal root ganglion and spinal nerve
Article first published online: 24 JAN 2005
Copyright © 1995 Wiley-Liss, Inc.
Volume 8, Issue 5, pages 339–346, 1995
How to Cite
Briggs, C. A. and Chandraraj, S. (1995), Variations in the lumbosacral ligament and associated changes in the lumbosacral region resulting in compression of the fifth dorsal root ganglion and spinal nerve. Clin. Anat., 8: 339–346. doi: 10.1002/ca.980080506
- Issue published online: 24 JAN 2005
- Article first published online: 24 JAN 2005
- Manuscript Revised: 23 DEC 1994
- Manuscript Received: 19 JUL 1994
- lumbosacral region;
- dorsal root ganglion;
- nerve compression
Sixty-five lumbosacral regions from adult cadavers were dissected and the position and relations of the lumbosacral ligament noted. The lumbosacral ligament was present in all specimens; in 22 (34%) it extended medially across the ventral ramus of the fifth lumbar nerve, and in six (9%) of these the underlying nerve was compressed and visibly flattened. On two of these specimens the nerve, together with its dorsal root ganglion, was removed, processed, and stained with Masson's trichrome. The compressed nerve showed increased thickness of endoneurial and perineurial connective tissue, and the cells of the dorsal root ganglion were smaller and surrounded by increased connective tissue, particularly at the periphery of the ganglion. Observation of the lumbosacral ligament and surrounding anatomical structures suggests that anatomical variation in this region may be attributed to the health of the lumbosacral articular elements. In those specimens showing compression of the fifth lumbar spinal nerve there was also narrowing of the lumbosacral interspace. In these the disc itself was compressed and showed degenerative changes. The articular processes at the lumbosacral joint were irregular, with thinning and fissuring of the articular cartilage. It is suggested that the processes which lead to the further development of the ligament, by the formation of additional fibrous bands, are mechanical in nature and result from instability at the lumbosacral region itself. Instability subsequently leads to the initiation of a chain of degenerative changes, involving pathology at the lumbosacral disc and zygapophyseal joints. Compression of the dorsal root ganglion occurs either within a narrowed inter vertebral foramen, or in the case described here just external to the foramen, while compression of the nerve occurs in the accessory ligamentous bands formed to resist the instability. A mechanism by means of which compression of the ganglion may give rise to pain is suggested. © 1995 WiIey-Liss, Inc.