The anatomy of the iliolumbar ligament.

During routine autopsies and anatomical dissections the anatomy of the iliolumbar ligament was studied and determined. In previous studies and literature, the ligament has been described to consist of three to five parts. We found the ligament to consist of only two parts: the anterior part and the posterior part, both attaching to the L5 transverse process. The insertion of the ligament has also been mentioned previously as attaching to the iliac crest. Both parts of the ligament were found to inset to the upper part of the iliac tuberosity, significantly lower than the iliac crest. The iliolumbar ligament cannot be visualized from the dorsal side before dissecting through all the lower back muscles and their fascias. We also found no evidence of any ligament part attaching to the L4 transverse process.