Iliolumbar membrane, a newly recognised structure in the back

Area of Science:

• Anatomical Sciences
• Human Anatomy
• Surgical Anatomy

Background:

• Despite extensive anatomical research, some human structures remain poorly understood.
• The thoracolumbar fascia and its deep layers are complex and require further investigation.

Purpose of the Study:

• To describe a newly identified membranous fascial anatomical entity, the iliolumbar membrane (ILM).
• To investigate the anatomical characteristics and potential function of the ILM.

Main Methods:

• Dissection of 40 human cadavers.
• Detailed anatomical description of the iliolumbar membrane's origin, course, and termination.
• Objective demonstration using ultrasound (7.5 MHz) and endoscopy (Stryker endoscope).

Main Results:

• The iliolumbar membrane (ILM) is a thick connective tissue structure originating from the thoracolumbar fascia.
• It courses inferior to the iliac crest, lateral to the posterior superior iliac spine.
• Variations were noted in its termination within subcutaneous fat, but its origin was consistently uniform.

Conclusions:

• The iliolumbar membrane (ILM) is a distinct anatomical entity.
• It may function as a natural barrier between posterior back muscles and gluteal muscles.
• Further research is warranted to elucidate its precise role in biomechanics and clinical relevance.