Femoral neuropathies can occur secondary to direct trauma, compression, stretch injury or ischemia.
Femoral neuropathy causes weakness of the quadriceps, which results in difficulty with ambulation.
Knowledge of femoral nerve anatomy is essential to understanding the mechanism of its injury and to localizing the lesion. The femoral nerve is part of the lumbar plexus. It is formed by L2-4 roots and reaches the front of the leg by penetrating the psoas muscle before it exits the pelvis by passing beneath the medial inguinal ligament to enter the femoral triangle just lateral to the femoral artery and vein. Approximately 4 cm prior to passing beneath the inguinal ligament, the femoral nerve is covered by a tight fascia at the iliopsoas groove. Compression of the nerve can occur anywhere along its course, but it is particularly susceptible within the body of the psoas muscle, at the iliopsoas groove and at the inguinal ligament.