MRI evaluation of the lumbar spine ligamentum flavum & its contribution to degenerative spinal stenosis
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Date
2018
Authors
Lian, Teh Hak
Journal Title
Journal ISSN
Volume Title
Publisher
Pusat Pengajian Sains Perubatan, Universiti Sains Malaysia
Abstract
Introduction: Lumbar spinal stenosis (LSS) is a medical condition in which the spinal canal
narrows and compresses the spinal cord and nerves at the level of the lumbar vertebra. Causes of
spinal stenosis include: hypertrophy of ligamentum flavum, herniated intervertebral disc and
hypertrophy of facet joint. Ligamentum Flavum (LF) is an anatomical structure, extends from the
2nd cervical vertebra through to the 1st sacral vertebra. It spans the vertebral lamina and forms the
dorsal surface of the spinal canal. The objective of this study is to understand the contribution of
ligament flavum in the pathoanatomy of degenerative lumbar spinal stenosis.
Methodology : This is a retrospective cross sectional study involving MRI of 50 young patients
without spinal stenosis and 50 older patients with spinal stenosis from Jan 2010 to Dec 2016 in
Hospital University Sains Malaysia. The young non stenotic patients have no signs and
symptoms of spinal stenosis. Meanwhile the older stenotic group of patients have signs and
symptoms of spinal stenosis and were operated.
Results & discussion : There is a significant strong linear relationship between thickness of LF
with age among the young non-stenotic group (P <0.05) whereas in older spinal stenosis group,
age has no significant relationship with thickness of LF . The thickness of LF in stenotic group is
significantly thickened compared to non stenotic group (P<0.05). There were more cranial
extension than caudal extension of LF in both groups and the thickest LF were situated at the
sublaminar region. The location of thickest LF is situated at lower 1/3 from the inferior edge of
lamina. There is no significant association between thickness of LF with the amount of herniated
intervertebral disc but herniated disc mostly occurs in conjunction with thickened ligamentum
flavum.Conclusion : Thickening of LF is an age dependent process ,however this increment of
thickening was not seen in spinal stenosis group. In LSS group L3/L4 level has the thickest LF
and has the most cranial extension. For complete flavectomy/ decompression, at least 12mm of
lamina from the inferior edge has to be removed .
Description
Keywords
Spinal stenosis