The iliolumbar ligament is a biomechanically important ligament in the lumbopelvic region. It functions to maintain the alignment of L5 on the sacrum during movement; it extends from the transverse processes of the 4th and 5th lumbar vertebrae to the iliac crest. The possible causes of ligament iliolumbar calcification or ossification include:
- Hypoparathyroidism.
- Ankylosing spondylitis - seropositive inflammatory spondyloarthropathies in general.
- Idiopathic skeletal hyperostosis – DISH.
- Degenerative diseases.
- Normal variation.