VH Dissector: Lower Limb: Hip, Medial & Anterior Thigh

Begin with the pelvis and right femur

Add the obturator externus muscle

Add the adductor magnus muscle

Add the gracilis muscle

Add the pectineus muscle

Add the adductor brevis muscle

Add the adductor longus muscle

Add the obturator artery, which supplies the medial compartment of the thigh. 

• It is a branch of the internal iliac artery and arises in the pelvic cavity. 

• It exits the pelvic cavity through a small opening in the obturator membrane along with the obturator nerve. 

• It divides into anterior and posterior branches, straddling the adductor brevis muscle. 

• Additionally, the posterior branch gives off an acetabular artery that gives rise to the artery to the head of the femur. 

Perforating branches of the femoral artery also contribute to the blood supply of the medial compartment.

Add the Obturator nerve (L2-L4), which is the main motor supply to the muscles of the medial compartment. 

• This nerve exits the pelvic cavity through the obturator foramen and membrane. 

• As it approaches the obturator externus muscle it divides into an anterior and posterior branches (like the artery).

• The posterior branch typically pierces through the obturator externus muscle and travels deep to the adductor brevis muscle.

• The anterior branch typically travels over the superior border of the obturator externus muscles and travels superficial to the adductor brevis muscle (deep to the adductor longus muscle). 

• The obturator nerve gives off a cutaneous branch that supply sensory to part of the medial thigh. 

The main cutaneous innervation of the medial thigh is from the anterior cutaneous branch of the femoral nerve. The ilioinguinal nerve (from the L1 nerve root of the lumbar plexus) provides cutaneous innervation to a small area of the superior medial thigh.

Add the Femoral nerve.

Add the Abdominal Aorta

Add the Common Iliac Arteries. These are the terminal branches of the abdominal aorta. The aorta divides at the level of the fourth lumbar vertebra, just to the left of the midline. The common iliac arteries descend infero-laterally, ending just anterior to the sacro-iliac joint at the level of the sacral promontory by dividing into internal and external iliac arteries. 

The artery is covered in peritoneum anteriorly and medially. The superior hypogastric plexus lies anterior to the upper end. The superior rectal vessels cross the artery on the left side. The ureter passes anterior to the artery near or at its point of division. Behind lies the sympathetic trunk, the bodies of the fourth and fifth lumbar vertebrae and the intervening discs. The obturator nerve, lumbosacral trunk and iliolumbar artery are situated more deeply. On the right, the lower end of the inferior vena cava, the right common iliac vein and the psoas major muscle lies laterally from above downwards. On the left, the common iliac vein lies medial to and slightly behind the artery, with psoas major lying at its lateral aspect.

Add the External Iliac Artery. This artery arises from the bifurcation of the common iliac artery and runs obliquely downwards and laterally along the medial border of psoas major to a point mid-way between the anterior superior iliac spine and the pubic symphysis. It passes behind the inguinal ligament to enter the thigh, where it becomes the femoral artery. It is enclosed in a thin fascial sheath with its accompanying vein. The external iliac artery gives off two large branches, the inferior epigastric artery and the deep circumflex iliac artery.

Add the Internal Iliac Artery. There are three branches of the internal iliac artery that provide blood supply to the lower limb:

1. The Superior Gluteal Artery enters the gluteal region superior to the piriformis muscle.

2. The Inferior Gluteal Artery enters the gluteal region inferior to the piriformis muscle.

3. The Obturator Artery passes into the medial thigh with the obturator nerve through the obturator canal. It also has a branch going to the acetabulum.

Add the Femoral Artery. This artery is the direct continuation of the external iliac artery at the point where the latter crosses deep to the inguinal ligament. It passes vertically down the anterior medial aspect of the thigh, to end at the adductor hiatus, where it becomes the popliteal artery.

Add the Inguinal Ligament. The femoral artery enters the femoral triangle where, for the first few centimeters of its course, it is enclosed in the femoral sheath (a funnel-shaped sleeve of fascia). It lies superficial as it crosses the femoral triangle where it is covered only by skin and fascia. Behind, from above downwards, are the tendon of psoas major and the pectineus, adductor longus and adductor magnus muscles.

Add the Femoral Vein. This vein follows the path of the femoral artery, iliac arteries as the blood returns to the inferior vena cava. The femoral vein and profunda vessels lie between the femoral artery and pectineus, with the femoral vein lying between the artery and adductor longus. The femoral vein lies medial to the artery in the upper part of the femoral triangle and posterior to it in the lower part. 

Add the deep femoral artery (profunda femoris) (NOT IDENTIFIED IN THIS CADAVER). It is the largest and most important of the many branches of the femoral artery and is given off in the femoral triangle. It runs initially lateral to and then posterior to the femoral artery. Vascular surgeons and radiologists usually refer to that part of the femoral artery proximal to the origin of the deep femoral artery as the ‘common femoral artery’, and the distal segment of the femoral artery as the ‘superficial femoral artery’. 

Proximal to the origin of the profunda femoris artery, the femoral artery gives a variable number of relatively small, superficial branches. The medial circumflex femoral artery usually arises from the deep femoral artery, but may arise directly from the femoral artery. 

The femoral artery enters the adductor canal in the medial part of the middle of the thigh. It is covered by muscle in the adductor (subsartorial) canal, with vastus medialis antero-laterally and sartorius antero-medially. In the distal part of the adductor canal the femoral artery gives off a branch called the ‘descending genicular artery’, which contributes to the anastomosis around the knee joint. The femoral artery then leaves the adductor canal through the adductor hiatus (a gap in the tendon of adductor magnus) to enter the popliteal fossa as the popliteal artery.

Add the Lateral Circumflex Femoral Artery which arises from the lateral side of the deep femoral artery. It passes laterally behind sartorius and rectus femoris, and divides into ascending, transverse and descending branches.

Add the Ascending Branch of the Lateral Circumflex Femoral Artery which passes upwards to the lateral side of the hip, anastomosing with the superior gluteal and deep circumflex iliac arteries.

Add the Descending Branch of the Lateral Circumflex Femoral Artery. It runs downwards behind rectus femoris and along the anterior aspect of vastus lateralis, which it supplies. The branch descends to the knee, anastomosing with the lateral superior genicular artery. 

Add the Medial Circumflex Femoral Artery. It arises from the posterior medial aspect of the deep femoral, or directly from the femoral artery. It passes backwards between the psoas major and pectineus, and then between obturator externus and adductor brevis, reaching the upper border of adductor magnus. 

It gives a branch to the hip joint and then divides into ascending and transverse branches. The transverse branch passes between quadratus femoris and adductor magnus to join the cruciate anastomosis. The Cruciate Anastomosis is a combination of the medial and lateral circumflex arteries, inferior gluteal artery, and the first perforating branch of the profunda femoris artery. They supply the thigh muscles and proximal end of the femur.  (NOT IDENTIFIED IN THIS CADAVER)

Add the Psoas Major muscle.

Add the Iliacus muscle.

Add the Vastus Medialis muscle.

Add the Vastus Intermedius muscle

Add the Vastus Lateralis muscle. 

Add the Rectus Femoris muscle.  Note that the rectus femoris is the only muscle of the quadriceps to cross the hip (originating at the AIIS).  therefore it assists in hip flexion as well as extending the leg at the knee joint like the rest of the quads.

Add the Quadriceps Femoris Tendon.

Add the Sartorius muscle. It is the longest muscle in the body.  As mentioned previously, it joins with gracilis and semitendinosus to insert on the medial surface of the superior part of the tibia at the pes anserinus.

Add the Tensor Fasciae Lata

Add the Inguinal Lymph Nodes.

Add the Pelvic Lymph Nodes

Add the Great Saphenous Vein. Note where it perforates the femoral sheath to empty into the femoral vein. 

The saphenous nerve accompanies the great saphenous vein from the knee to the medial malleolus. The saphenous nerve is the only branch of the femoral nerve that passes distal to the knee joint and it is purely cutaneous.