Abstract:

BACKGROUND: Lumbar disc degeneration and thickening of ligamentum flavum (LF) are considered to be associated with changes in aging. However, the natural course of disease of LF thickening evaluated by MRI is poorly understood.
OBJECTIVE: To evaluate the relationships among thickness, age, intervertebral space level and degeneration of intervertebral disc by MRI.
METHODS: The thickness of LF was measured at L2/3, L3/4, L4/5 and L5S1 levels (n = 712) using MRI in 178 patients with low back pain and/or leg pain. The relationships among thickness, age, intervertebral space level and degeneration of intervertebral disc were detected.
RESULTS AND CONCLUSION: The thickness LF increased with age; however, the increments at L4/5 and L5S1 levels were larger than that at L2/3 and L3/4 levels. At L4/5 level, the thickness of LF was over 3.0 mm in patients in the 20–29 age brackets. If all patients with a thickened LF at L2/3 (>3.0 mm), then the remaining levels of LF were thickened. In elderly patients, there was no correlation between the thickness of LF and the degeneration of intervertebral disc. The results show that thickening of LF at L4/5 had already thickened in patients in the 20–29 age bracket. However, the thickening of LF was not the buckling of the LF into the spinal canal with degeneration of intervertebral disc. The thickness of LF at L2/3 can serve as an indicator of lumbar spinal canal stenosis at multiple levels.