2 – Anatomy

The important target nerves for the lumbar plexus block are the femoral nerve (L2-L4), the obturator nerve (L2-L4), and the lateral femoral cutaneous nerve (L2-L3)

The other lumbar plexus nerves are not targeted with the lumbar plexus block, but are blocked selectively for some purposes (see other modules in this learning program): The iliohypogastric nerve (T12-L1), the ilioinguinal nerve (L1) and the genitofemoral nerve (L1-L2)

The femoral nerve innervates the iliopsoas, pectineus, sartorius, and quadriceps femoris muscles. It supplies sensory innervation to the hip joint, the anterior cutaneous branches of the thigh, the knee joint and via the saphenous nerve sensory branches to the knee region, the medial leg including branches to the medial ankle and subtalar joint capsules

The obturator nerve innervates the adductors (longus, brevis, magnus), gracilis, pectineus, and obturator externus

The lateral femoral cutaneous nerve supply sensory innervation to the lateral thigh