Femoral Nerve Injury (L2-L4)
Overview
Plain-Language Overview
A femoral nerve injury affects a major nerve in the thigh that controls muscles responsible for leg movement and sensation in the front of the thigh and inner lower leg. This nerve injury can cause weakness in straightening the knee and difficulty walking, as well as numbness or tingling in the affected areas. The femoral nerve is part of the peripheral nervous system, which connects the spinal cord to muscles and skin. Damage to this nerve often results from trauma, surgery, or compression in the groin or pelvis. The injury impacts both motor function and sensory perception, leading to noticeable changes in leg strength and feeling.
Clinical Definition
Femoral nerve injury (L2-L4) is a peripheral neuropathy involving damage to the femoral nerve roots originating from spinal levels L2 to L4. The injury typically results from direct trauma, pelvic or hip surgery, retroperitoneal hemorrhage, or compression by masses. This nerve innervates the quadriceps femoris muscle group, which is essential for knee extension, and provides sensory innervation to the anterior thigh and medial leg via the saphenous nerve. Clinically, it presents with quadriceps weakness, impaired knee extension, decreased patellar reflex, and sensory loss in the anterior thigh and medial leg. The condition is significant because it impairs ambulation and increases fall risk. Electrophysiological studies and imaging help localize the lesion and exclude other causes.