The skin of the front of the thigh is supplied by seven cutaneous nerves derived directly, or indirectly, from the lumbar plexus. In addition, the skin over the upper lateral part of the thigh is supplied by the lateral cutaneous branch of the subcostal nerve.
The ilioinguinal nerve (L1) emerges at the superficial inguinal ring, and supplies the skin at the root of the penis or over the mons pubis in the female, the anterior one-third of the scrotum or labium majus, and the superomedial part of the thigh.
The femoral branch of the genitofemoral nerve (L1, L2) pierces the femoral sheath and the overlying deep fascia 2 cm below the midinguinal point, and supplies most of the skin over the femoral triangle.
The lateral cutaneous nerve of the thigh (L2, L3) is a branch of the lumbar plexus. It emerges behind the lateral end of the inguinal ligament, divides into anterior and posterior branches, and supplies the skin on the anterolateral side of the thigh and on the anterior part of the gluteal region.
The intermediate cutaneous nerve of the thigh (L2, L3) is a branch of the anterior division of the femoral nerve. It pierces the deep fascia at the junction of the upper one-third and middle one-third of the thigh. It divides into two or more branches and supplies a strip of skin on the front of the thigh extending from the sartorius to the knee.
The medial cutaneous nerve of the thigh (L2, L3) is a branch of the anterior division of the femoral nerve. It divides into anterior and posterior divisions. The nerve supplies the skin on the medial side of the lower two-thirds of the thigh, and of the upper one-third of the leg.
The saphenous nerve (L3, L4) Is a branch of the posterior division of the femoral nerve. It pierces the deep fascia on the medial side of the knee, runs down in front of the great saphenous vein, and supplies the skin on the medial side of the leg and foot up to the ball of the big toe.
Before piercing the deep fascia the saphenous nerve gives off the infrapatellar branch which runs downwards and laterally, and supplies the skin over the ligamentum patellae.
Sometimes the cutaneous branch of the anterior division of the obturator nerve (L2, L3) supplies the skin of the lower one-third of the medial side of the thigh in common with the medial cutaneous nerve.