Goal of the Study?
In this study 1 the authors use MRI to measure changes in the facet angles of the lumbar spine and analyze the relationship between angle changes and the herniated lumbar intervertebral disc.
Why are they doing this study?
The incidence of lower back pain (LBP) is prevalent in today’s society and can place an enormous burden on individuals and health systems. There are many causes of LBP, including lumbar facet joint (LFJ) degeneration, lumbar disc herniation (LDH), compression of nerve roots, and others. There is currently little understanding of the role of lumbar facet joint angle changes and lumbar disc herniation play in LBP. The authors comment that there is a lack of knowledge on whether the structural abnormality of the spine resulting from LFJ degeneration causes the abnormal force of the lumbar intervertebral disc herniation. Additionally, there is a need to understand whether lumbar facet joint angle changes are common in patients with lumbar disc herniation.
What was done?
First, the authors review both direct and indirect signs of lumbar disc herniation as seen on MRI. They state that MRI provides an advantage to obtain horizontal and sagittal three-dimensional scanning of the spinal cord, subarachnoid space, vertebral body and intervertebral discs. They review the various signs of the nucleus pulposus, schmorl nodules, lumbar dural sac, lumbar spinal cord and nerve root compression.
The authors used cross-sectional images of the MRI to measure angles of the articular processes on both sides. They included 500 cases of patients with a clinical diagnosis of lumbar disc herniation and concurrent lumbar disc MRI examination. This included 227 males and 273 females with an average age of 41. This was broken down into 137 cases in the central LDH group, 140 cases in the left paralateral LDH group, 127 cases in the right-side LDH group and 75 cases in the control group. The cases were based on those who met the diagnostic criteria over 18 and relevant imaging and clinical data. Statistical software was used for statistical analysis.
What did they find?
The authors found no statistically significant relationship between age, gender, height and weight of the groups and LDH. They found no statistically significant relationship between MRI and CT measurements of the facet joint angle. They argue a correlation between the changes illustrated in MRI images of lumbar disc herniation and the TCM syndromes of lumbar intervertebral disc herniation. They found that the L4/5 and L5/S1 segments of the lesion in the central LDH group and the left paralateral LDH and right-side LDH were all significantly different from the control group. Facet joint asymmetry is closely related to lateral lumbar disc herniation. However, the asymmetry of the facet joints is not related to the central lumbar disc herniation. They argue that MRI has a high sensitivity concerning measuring angles of the facet joint and changes to those angles and how they correlate with herniated discs.
Why do these findings matter?
Understanding the relationship between lumbar facet joint angle changes and lumbar disc herniation is useful for preventing and treating LBP.