Presentation
Lower back pain and reduced motion.
Patient Data

There is a bilateral ossification of the iliolumbar ligaments.
There are also a dextro- convex scoliosis and pronounced degenerative changes.
Case Discussion
Iliolumbar ligament has two separate bands, both originate from the transverse process of the fifth lumbar vertebra and runs laterally and posteriorly to the iliac crest, attaching to the anterior and posterior margin of the iliac crest, respectively.
Quadratus lumborum muscle is placed between these two bands.
This ligament does not exist at birth. He originates from muscle fibres of quadratus lumborum muscle due to gradual metaplasia, as a response to the stresses due to transit to erect posture.
The most important role of the iliolumbar ligament is maintaining the stability of the lumbosacral junction.
Diffuse ossification of the iliolumbar ligaments is a finding common to both degenerative disease and diffuse idiopathic skeletal hyperostosis (DISH), but may also occur in young patients with reactive arthritis
This patient's problems are probably due to scoliosis and degenerative changes.