What Is the Saphenous Nerve?

It starts from the femoral nerve and enters the adductor tube in the femoral triangle with the outside of the femoral artery. It passes through the adductor tendon plate at the lower end of the adductor tube and runs between the sartorius muscle and the gracilis muscle. A deep fascia is worn on the inner side of the knee joint with the saphenous vein descending, and the branches are distributed under the sacrum, the inner side of the lower leg, and the skin of the inner side of the foot.

It starts from the femoral nerve and enters the adductor tube in the femoral triangle with the outside of the femoral artery. It passes through the adductor tendon plate at the lower end of the adductor tube and runs between the sartorius muscle and the gracilis muscle. A deep fascia is worn on the inner side of the knee joint with the saphenous vein descending, and the branches are distributed under the sacrum, the inner side of the lower leg, and the skin of the inner side of the foot.

Chinese name

Saphenous nerve

Foreign name

saphenous nerve

Category

Longest cutaneous nerve

From

Femoral nerve

Saphenous nerve , femoral nerve:

(I) Introduction:

It is composed of the posterior thigh of the anterior branch of the 2nd to 4th lumbar nerves and is the largest nerve in the lumbar plexus. After it is issued, it first descends between the psoas muscle and the diaphragm muscle, and penetrates the deep muscle space of the inguinal ligament, slightly outside the inguinal midpoint, reaches the thigh, and then divides into several branches.

(B) Classification:

Muscle branch

The femoral nerve is a motor nerve of the thigh anterior muscle group. It emerges immediately after the midpoint of the inguinal ligament and branches immediately. Its muscle branches enter and dominate the sartorius muscle, rectus femoris, lateral femoris muscle, and intermediate femoral muscle. Hair branch to knee joint muscle; another branch to pubic muscle; muscle branch sends out small joint branches into hip and knee joints.

2. Leather branch:

The longest cutaneous branch is called the saphenous nerve, which is the terminal branch of the femoral nerve. As the femoral artery enters the adductor tube, it descends subcutaneously on the inner side of the knee joint, with the saphenous vein descending along the medial side of the calf to the medial edge of the foot. Under the skin of the chin, medial side of the calf and medial edge of the foot.

(3) Damage:

Femoral nerve injury, difficulty in flexing the thigh, difficulty in stretching the calf in the sitting position, difficulty in walking; atrophy of the quadriceps muscles, prominent sacrum; disappearance of knee jump reflexes; sensory disturbances in front of the thighs and inside of the calves.

Saphenous nerve II, femoral triangle:

The femoral triangle is a triangular area located on the front 1/3 of the thigh, with the bottom side facing upward and the tip facing downward. Its upper boundary is the inguinal ligament; the lateral boundary is the medial edge of the sartorius muscle; the medial boundary is the medial edge of the long adductor muscle; the front wall is the broad fascia; and the back wall is the depression formed by the iliopsoas muscle, pubic muscle, and long adductor muscle. groove.

The superficial fascia of the femoral triangle is thick, and the superficial inguinal lymph nodes are arranged in a "T" shape below the inguinal ligament and around the end of the great saphenous vein. It houses lymph of the perineum, abdominal wall, buttocks and lower limbs. The genus branch at the end of the great saphenous vein, the cutaneous branch from the femoral artery, and the cutaneous branch of the femoral nerve are all distributed in this area. The ends of the great saphenous vein are the external genital vein, the superficial abdominal vein, and the internal and external femoral veins. When the saphenous varicose veins are ligated at a high level, these branches need to be cut and ligated one by one, otherwise the venous blood will flow backward and the operation will fail. When inguinal skin flaps are taken, the superficial abdominal wall and superficial circumflex arteries of the femoral artery and accompanying veins of the same name are often reserved for vascular anastomosis. In addition, the genital femoral nerve and lateral femoral cutaneous nerve also appear in this area; the former is placed under the midpoint of the inguinal ligament on the upper femoral skin and scrotum; the latter is about 5 cm below the anterior superior iliac spine and penetrates the deep thigh fascia To the superficial fascia, cloth on the outer skin of the femur.

The broad fascia of the anterior wall of the femoral triangle has a gap about 4 cm outside the pubic tubercle, which is called a saphenous vein hiatus. It is closed by the sieve fascia. The ethmoid fascia is penetrated by the superficial blood vessels of the femur, the great saphenous vein, and the lymphatic vessels. At the base of the femoral triangle, the important contents arranged from the outside to the inside are the femoral nerve, femoral artery, femoral vein and lymph nodes, and femoral canal, but at the apex of the femoral triangle, the femoral artery is located in front of the femoral vein. The main branch of the femoral artery is the deep femoral artery. The deep femoral artery has internal and lateral femoral arteries. The anastomosis of the medial and lateral femoral arteries and the first perforating branch of the deep femoral artery and the inferior gluteal artery formed at the back of the femur. The femoral sheath is located on the femoral triangle and is formed by the extension of the abdominal transverse fascia and the iliac lumbar fascia. These include the femoral artery, femoral vein, and femoral canal. The femoral sheath is wide and narrow, funnel-shaped, and is about 3 to 4 cm long. The sheath cavity is divided into three outer, middle, and inner compartments by two mediastinums: the lateral compartment accommodates the femoral artery, the middle compartment accommodates the femoral vein, and the medial compartment is the femoral canal. There are 1 or 2 lymph nodes in the femoral tube, called deep inguinal lymph nodes (Cloquet nodes). The lower end of the sheath is fused with the adventitia of the blood vessel.

The vascular space and muscle space of the femoral triangle upward through the deep surface of the inguinal ligament communicate with extraperitoneal tissue. The length of the femoral tube is about 1.5cm. The upper end is the entrance of the femoral tube, called the femoral ring. The inner side wall is inclined downward and outward, and merges with the adventitia of the femoral vein. The anterior border of the femoral ring is the inguinal ligament, the posterior border is the pubic comb ligament, the medial border is the free margin of the lacunar ligament, and the lateral is the femoral vein. The diameter of the thigh is 0.8-1cm, which can only accommodate the little fingertips. The cuff is filled with extra-peritoneal fat, and the peritoneum that covers the cuff appears as a small nest called the femoral concavity. If the contents of the abdominal cavity protrude through the femoral canal, it is called a femoral hernia.