The iliolumbar ligament is described as a biomechanically important ligament for the lumbopelvic region; it extends from the transverse processes of the 4th and 5th lumbar vertebrae to the iliac crest. Alterations of the iliolumbar ligament are attributed to trauma and assumed to be an important source of low back pain syndrome having a great economic impact. Changes in iliolumbar ligament morphology relating to the low back pain syndrome have not been deeply studied.
The iliolumbar ligament (IL) is a culpable ligament of reducing sacroiliac joint movement, due to its cranial margin. The IL engages in body weight transmission to the lower extremity, stabilizing the vertebral spine and the pelvis, as the major ligament responsible for that. Besides that, the spinal flexion is a consequence movement, unleashed by the anterior band of the IL.
Keywords: ligaments, anatomy & histology, female, adult, radiography
The iliolumbar ligament (IL) is a culpable ligament of reducing sacroiliac joint movement, due to its cranial margin.1 The IL engages in body weight transmission to the lower extremity, stabilizing the vertebral spine and the pelvis, as the major ligament responsible for that.1 Besides that, the spinal flexion is a consequence movement, unleashed by the anterior band of the IL.1
The ligaments that afford to lumbosacral spine being stable with the pelvis include the interosseous, ventral and dorsal sacroiliac, sacrospinous, sacrotuberous, and iliolumbar ligaments.2 IL is one of the main references in the counting of the vertebrae, especially lumbar, and transition vertebrae.3
83 years-old female patient complains of a progressive backache pain for five years. She denies trauma or previous disease. Her parents were healthy. Lumbar spine and pelvis X-ray were performed, and demonstrated:
The patient did not present hyperparathyroidism, ankylosing spondylitis or Idiopathic skeletal hyperostosis, having a degenerative disease or a variation of normality as a probable etiology of the iliolumbar ligament ossification (Figure 1) (Figure 2).
The IL is a part of the three vertebropelvic ligaments.4 The other two are the sacrotuberous and the sacrospinous ligaments and are characterized as being linked to the hip and the inferior anterior part of the transverse process of the fifth lumbar vertebra with, sporadically, a fragile attachment to the transverse process of the fourth lumbar vertebra.4 The ligament is settled to course laterally and lightly posteriorly and to attach into the top of the iliac crest.4
Luk et al.,3 demonstrated that there’s no iliolumbar ligament at birth. However, the iliolumbar ligament develops continuously in the first decade and reaches complete separation in the second decade of life.3 They also stated that with advancing age, the intervertebral discs degenerate and iliolumbar ligaments undergo gradual hyalinization, fatty infiltration, and myxoid deposition.4
There is also described a lower band of the ligament, often denominated the lumbosacral ligament, which courses from the lower aspect of the fifth lumbar transverse process to the anterior part of the all of the sacrum.4 Along with a robust L5-S1 intervertebral disc, the iliolumbar ligament stabilizes the lumbosacral junction.4
Image tests that detect the ossification of the ligament iliolumbar are radiography, as our case, CT scan, and MRI.5 In one case it was detected on bone scintigraphy.6 In degenerative spondylolisthesis, it is recognized that the sliding of the fourth lumbar vertebra on the fifth vertebra is six times more common when compared to the slide between the fifth lumbar vertebra on the sacrum.7
The possible causes of ligament iliolumbar calcification or ossification, include:
There is one case report of iliolumbar ligament ossification in a patient with ankylosing spondylitis, but seronegative for HLA-B27.7
In cases of iliolumbar ligament ossification, seropositive inflammatory spondyloarthropathies should be promptly investigated, especially when there are symptoms.
This finding should only be taken as a normal variation when the symptoms do not exist and possible pathologies are discarded.
Not applicable.
© . This is an open access article distributed under the terms of the, which permits unrestricted use, distribution, and build upon your work non-commercially.