Video: Main arteries of lower limb

Doctor, this patient presents with cyanosis of the distal limb and is complaining of intermittent claudication of his left leg. His posterior tibial and dorsalis pedis pulses are both monophasic suggesting peripheral arterial disease. I think we're going to have to bring him in for surgery. I agree. Let's get him prepped and bring him in. But, are we ready? We're about to go in to do a percutaneous transluminal angioplasty of the femoral artery, but wait! Where should I make the incision, and actually, where do I find the artery? Hmm…maybe we should revise the main arteries of the lower limb before we begin, which is exactly what we're going to learn about today.

In order to keep things as simple as possible, we'll explore the main arteries of the lower limb through four main regions – the hip and thigh, the knee, the leg, and the foot. This will aid in developing our understanding of the area or region which these arteries supply. We'll finish this tutorial by taking a quick look at a clinical note related to one of the major arteries of the lower limb. So let's begin!

Like the rest of the body, the arterial supply of the lower limb originates from the aorta which delivers oxygenated blood from the heart. The abdominal aorta terminates around the level of the pelvic brim where it divides or bifurcates into two common iliac arteries. The common iliac arteries divide further into internal and external iliac arteries which supply structures within and around the pelvis, perineum, and lower limb.

The external iliac artery courses inferiorly and does not enter the perineum. It travels beneath this structure here, which is known as the inguinal ligament, to enter the thigh. One of the main roles of the external iliac artery is to supply the lower limb; however, it does supply some structures of the anterior abdominal and pelvic walls.

The internal iliac artery travels within the pelvic cavity dividing into numerous branches to supply the pelvic walls and organs, the external genitalia and perineum as well as the gluteal region and medial thigh. Therefore, we can say that all arteries of the hip and thigh region originate as branches from the internal and external iliac arteries.

Let's take a closer look at some of the branches which supply the hip and the thigh region now.

The obturator artery is one of the branches of the internal iliac artery that supplies the medial aspect of the anterior thigh supplying muscles within this region as well as the head of the femur. Another branch of the internal iliac artery relevant to the lower limb are the gluteal arteries. Both superior and inferior gluteal arteries arise from the internal iliac artery within the pelvis and travel posteriorly to reach the muscles of this region.

The main artery of the lower limb is the femoral artery. The femoral artery originates as a continuation of the external iliac artery as it travels deep to the inguinal ligament. It gets its name from the Latin word femoralis which means ‘of the thigh.’ It continues beneath the inguinal ligament to reach the anterior thigh. The femoral artery can be palpated within a small medial sub-region of the upper anterior thigh – the femoral triangle.

The femoral triangle is bordered by the sartorius muscle laterally, the adductor longus muscle medially and the inguinal ligament superiorly. So if you ever need to find the femoral artery, just find one of these muscles and work your way in or out.

The proximal part of the femoral artery gives off several smaller branches to the anterior abdominal wall and superficial pelvis. However, the main branch of the femoral artery is the deep femoral artery or the profunda femoris artery as it is also known. This artery travels deep to the femoral artery and gives off what are known as perforating branches posterior to the femur to supply the posterior thigh. Circumflex branches of the deep femoral artery also supply the neck of the femur and hip region.

As the femoral artery descends through the thigh, it travels through a hiatus, or opening, along one of the large muscles of the medial thigh – the adductor magnus. At this point, this artery becomes known as the popliteal artery. After passing through the adductor magnus muscle, it curves around to reach the hollow of the back of the knee – the popliteal fossa. The short popliteal artery lies deep within the popliteal fossa and is surrounded with fat, therefore, sometimes making it a tricky artery to palpate.

The knee region is supplied by several small interconnected genicular arteries which mainly originate from the popliteal artery. The genicular arteries connect or anastomose with the surrounding small arteries of the leg and thigh to supply the knee. An anastomosis is any connection between adjacent blood vessels such as arteries.

Now, let's take a look at the arteries that supply the leg.

Moving distally to the leg, we can see its main arteries originate as a continuation of the popliteal artery. As the popliteal artery travels to leave the popliteal fossa, it bifurcates into two terminal branches – the anterior tibial and posterior tibial arteries.

The anterior tibial artery travels between the tibia and fibula to reach the anterior compartment of the leg and supplies all muscles of this region. It gives off further branches around the ankle region and to the foot, but we'll look at these in just a moment. The other terminal branch of the popliteal artery – the posterior tibial artery – continues distally through the posterior leg supplying its muscles as well as the tibia itself. The posterior tibial artery terminates between the medial malleolus and the calcaneus on the plantar aspect of the foot. This part of the artery runs quite superficially within this region and therefore can be easily palpated. Why not try it on yourself using your index and middle finger?

One of the main branches of the posterior tibial artery is the fibular artery which branches shortly after the terminal bifurcation of the popliteal artery. It supplies the muscles of the posterolateral aspect of the leg as well as the fibula. At the distal end of the leg, we meet a network of connecting vessels known as the malleolar arteries. These arteries supply the ankle region and are named after the knobbly bony protrusions of the ankle – the malleoli. The malleolar arteries include the medial malleolar branch of the posterior tibial artery and the lateral malleolar branch of the fibular artery.

The final region of the lower limb is the foot. The foot is divided into superior, or dorsal, and inferior, or plantar, regions of the foot. The dorsal region faces upwards while the plantar region is the surface that makes contact with the ground or the sole of the foot. Arteries that supply these regions originate from the anterior and posterior tibial arteries.

The dorsalis pedis artery – dorsalis for the dorsal aspect of the foot and pedis referring to the foot – is the distal continuation of the anterior tibial artery in the foot. This artery supplies muscles of the dorsal region of the foot. The dorsalis pedis artery travels quite superficially on the dorsal surface of the foot and therefore can usually be palpated along its root. The dorsalis pedis artery gives off several branches – the medial and lateral tarsal arteries, the arcuate artery before finally terminating as the deep plantar artery and the first dorsal metatarsal artery.

Let's take a quick look at each of these branches now.

The medial and lateral tarsal arteries are two branches that arise from the dorsalis pedis artery on the dorsum of the foot. These arteries supply the tarsal region. The tarsal region is made up of the proximal seven tarsal bones of the foot. The lateral tarsal artery anastomoses with the arcuate artery at the base of the metatarsal bones supplying structures within this region while the medial tarsal artery travels over the medial tarsal bones and anastomose with the medial malleolar network.

Another branch of the dorsalis pedis artery is the arcuate artery. This artery remains on the dorsal surface of the foot at the base of the metatarsals supplying muscles and structures of that region. Before anastomosing with the lateral tarsal artery, the arcuate artery gives rise to the dorsal metatarsal arteries which travel alongside metatarsals 2 to 5.

The first dorsal metatarsal artery which travels alongside the first metatarsal arises directly from the dorsalis pedis artery. The dorsal metatarsal arteries terminate as they reach the phalanges or bones of the toes and continue as the dorsal digital arteries. These digital arteries supply the dorsal toes or digits as they are correctly termed. The deep plantar artery travels between the first and second digit to connect with the deep plantar arch on the plantar surface of the foot.

The final arteries of the foot are the plantar arteries. As the posterior tibial artery travels down the posterior aspect of the leg, it travels posterior to the medial malleolus to reach the sole of the foot. It then terminates as a bifurcation forming the medial and lateral plantar arteries of the foot. The medial plantar artery travels up to the tip of the great toe or hallux as it is anatomically termed. It supplies the structures of the medial aspect of the sole of the foot.

The lateral plantar artery begins to travel up the lateral aspect of the foot but takes an abrupt turn to form an arch on the plantar surface of the base of the metatarsal bones. This arch is known as the deep plantar arch of the foot and it gives off perforating branches which are known as the plantar metatarsal arteries. These arteries supply the plantar surface of digits 2 to 5. The deep plantar arch terminates by anastomosing or connecting with the deep plantar artery in between the first and second metatarsal bone.

Now that we've met all the main arteries of the lower limb, let's take a quick look at some clinical notes.

That drama preview that we saw earlier seemed pretty intense, didn't it? Why don't we pick up where we left off and find out what a percutaneous transluminal angioplasty is? As with any artery in the body, narrowing or blockages due to plaque and atherosclerosis may develop. When this occurs within the femoral artery, the lower limb suffers as there is a decrease in blood flow to this region. A decrease in blood flow to the lower limb can lead to poor healing abilities, necrosis, and if left untreated, even amputation. That's why it's important to carry out a percutaneous transluminal angioplasty of the femoral artery.

This procedure is minimally invasive and avoids the risk of open vascular surgery. The femoral artery can easily be accessed through the femoral triangle of the anterior thigh. Once the blockage is located, a catheter with a small balloon at its end is inserted into the artery. When the catheter has reached the site of narrowing, the balloon is inflated to push away all the plaque and buildup that was blocking the artery. A stent can then be inserted to keep the artery open and maintain blood flow to the lower limb.

Now we've come to the end of the tutorial on the main arteries of the lower limb. Let's have a quick look at what we learned today.

We began this tutorial by identifying where the blood supply of the lower limbs originates from. The aorta carries oxygenated blood from the heart through the thorax down through the abdomen to divide into two common iliac arteries. The common iliac arteries further divide into the external and internal iliac arteries. The obturator artery is a small artery on the medial aspects of the anterior thigh. This artery originates from the internal iliac artery and travels medially to supply the head of the femur and thigh. The gluteal arteries are also branches of the internal iliac artery and leave the pelvis posteriorly to supply the gluteal and hip region.

The femoral artery is a continuation of the external iliac artery and is the main artery of the lower limb. The femoral artery supplies the anterior and medial thigh region. One of the main branches of the femoral artery is the deep femoral artery. This artery supplies the posterior thigh. The popliteal artery is the continuation of the femoral artery. This artery is the main blood supply to the knee. The popliteal artery sits posterior to the knee within the popliteal fossa and gives off small branches which anastomose and supply the medial, lateral, and anterior knee.

Moving from the knee to the leg, we met the anterior and posterior tibial arteries. The popliteal artery bifurcates at the inferior popliteal fossa into the anterior and posterior tibial arteries. The anterior tibial artery curves around to the anterior leg and supplies this region while the posterior tibial artery supplies the posterior leg. The posterior tibial artery gives off the fibular artery which supplies the posterior and lateral aspects of the leg. As the anterior tibial artery travels down the leg, it gives off small malleolar branches at the ankle. These arteries supply the ankle region.

The anterior tibial artery terminates at the anterior ankle and continues as the dorsalis pedis artery. The dorsalis pedis artery branches into the tarsal arteries. arcuate artery, and first dorsal metatarsal artery before terminating as the deep plantar artery. The arcuate artery remains on the dorsum of the foot giving off the dorsal metatarsal arteries which supply digits 2 to 5. The first dorsal metatarsal artery along with the rest of the dorsal metatarsal arteries continue as the digital arteries to the toes or the digits.

The deep plantar artery travels inferiorly to the sole of the foot to anastomize with the deep plantar arch. The posterior tibial artery terminates by dividing into the medial and lateral plantar arteries as it reaches the sole of the foot. The medial plantar artery supplies the medial aspect of the foot while the lateral plantar artery supplies the lateral proximal foot and forms the deep plantar arch of the foot. The deep plantar arch gives off branches which supply the digits of the plantar aspect of the foot. The deep plantar artery anastomoses with the deep plantar arch between the first and second metatarsal.

We then came to some clinical notes. Here we explored the complications of atherosclerotic buildup within the femoral artery and how to remove these blockages using a percutaneous transluminal angioplasty of the femoral artery.

We've come to the end of this tutorial. I hope you enjoyed learning about the main arteries of the lower limb. Happy studying!