Iliolumbar ligament originated from the transverse process of L5 and inserted deep into the ventral margin of the iliac crest. Its main function is to strengthen the lumbosacral joint.
The Iliolumbar ligament can be calcified or ossified and the differential diagnosis includes:
- normal variant
- degenerative changes
- diffuse idiopathic skeletal hyperostosis
- ankylosing spondylitis
- metabolic e.g. hypoparathyroidism