Dorsal Spinal Ligamentum Flavum Thickening: A Magnetic Resonance Imaging Study

Abstract

Study DesignA retrospective radiological study of the ligamentum flavum (LF).PurposeWe determined the relationship of dorsal spinal LF thickening with age and sex using magnetic resonance imaging (MRI). We also determined whether LF thickening has a predominant tendency to occur at a specific dorsal level and on a specific side.Overview of LiteratureMany researchers have studied LF thickness at dorsal levels in patients with compressive myelopathy. However, there is a dearth of literature pertaining to the study of dorsal LF thickness in patients without myelopathy.MethodsLF thickness was measured at dorsal levels from T1 to T12 on both sides using MRI in 100 individuals. The patients were divided into three groups based on age: 20 to 40, 41 to 60, and >60 years. On axial T2-weighted imaging at the mid-disc level, LF thickness was measured perpendicular to the lamina border, either at half the length of LF or at maximum thickness, whichever was greater.ResultsWe found that LF thickness does not increase significantly with increasing age and there was no significant disparity in LF thickness between the sides and sexes. We also found that there was a significant increase in LF thickness at the T10–T11 level (mean value, 3.27±0.94 mm).ConclusionsLF thickness does not appear to have any side/sex dominance. LF thickening has a predominant tendency to occur specifically at the T10–T11 level. This may be due to maximum tensile strength and mobility at this level. Because there is an increased tendency for LF thickening at the T10–T11 level, this may be used as a reference point for counting the vertebral levels.

Advanced Quantitative Spine Imaging

“…119 Maximum thickness of the ligamentum flavum in the thoracic spine is at the T10-T11 level (3.3 AE 0.9 mm), possibly due to larger tensile forces and mobility at this level. 119 In the lumbar spine, ligamentum flavum thickness > 4 mm is considered hypertrophy. 102,120 The ligamentum flavum tends to be thickest at L4-L5 followed by L5-S1 and is $ 5 to 10% thicker on the left side.…”

“…118 Average thickness of the ligamentum flavum in the thoracic region is 2.6 AE 0.7 mm, thinnest in the upper and thickest in the mid-to lower thoracic region. 119 No age variation was apparent. 119 Maximum thickness of the ligamentum flavum in the thoracic spine is at the T10-T11 level (3.3 AE 0.9 mm), possibly due to larger tensile forces and mobility at this level.…”

“…119 No age variation was apparent. 119 Maximum thickness of the ligamentum flavum in the thoracic spine is at the T10-T11 level (3.3 AE 0.9 mm), possibly due to larger tensile forces and mobility at this level. 119 In the lumbar spine, ligamentum flavum thickness > 4 mm is considered hypertrophy.…”

<p>CT-Guided Percutaneous Lumbar Ligamentum Flavum Release by Needle Knife for Treatment of Lumbar Spinal Stenosis: A Case Report and Literature Review</p>

“…15 Chelladurai et al reported that there was no significant difference in LFH between the two sides and sex. 16 Currently, there are two treatment approaches in patients with thickening of the LF: operative treatment and nonoperative treatment. For operative treatment, several methods of excision of the LF, eg, decompressive laminectomy and minimally invasive decompression, are performed under general principles of full decompression and spinal stability.…”