The lateral femoral cutaneous nerve originates directly from the lumbar plexus and has root innervation from
L2-3.
The nerve runs through the pelvis along the lateral border of the psoas muscle to the lateral part of the inguinal ligament.
Here, it passes to the thigh through a tunnel formed by the lateral attachment of the inguinal ligament and the anterior superior iliac spine.
This is the most common site of entrapment.
Entrapment causes a painful mononeuropathy of the lateral femoral cutaneous nerve (LFCN).
It is a purely sensory nerve, innervating the anterolateral thigh.
The clinical history, and examination, is usually sufficient to make the diagnosis.
The image illustrates the path of the lateral cutaneous nerve showing area of compression.