The Anatomy of the Anterior Tibial Artery

A major branch of the popliteal artery, the anterior tibial artery delivers oxygenated blood to the anterior (front-facing) compartment of the leg as well as the dorsal (upper) surface of the foot. Paired with the anterior tibial vein along its downward course, it arises in the popliteal fossa just behind the knee, moves downward along the tibia and fibula (the major bones of the lower leg), and then crosses the anterior aspect (front portion) of the ankle joint. At this point it becomes the dorsalis pedis artery, which supplies the top of the foot.

Given its function and location, the anterior tibial artery can play a part in or be affected by a number of health conditions. Notable among these are acute and chronic compartment syndrome, wherein the artery can become constricted, leading to pain and swelling. This is considered a medical emergency and surgery is required. Furthermore, in a specialist’s office, this artery may be palpated (squeezed) by a physician to assess for the presence of peripheral artery disease, characterized by blockages in important arteries.

Anatomy

Structure and Location

The anterior tibial artery, alongside the posterior tibial artery, splits off as the popliteal artery terminates in the popliteal fossa, a cavity behind the knee near the popliteal muscles. It moves downward and to the front, passing between the tibia and fibula, the two major bones of the lower leg, through a tough connective tissue called the interosseus membrane. After passing through this membrane, the artery courses downward between two muscles of the front of the lower leg: the tibialis anterior and extensor digitorum longus muscles. From there, it accesses the front of the ankle joint, where it becomes the dorsalis pedis artery.

Close to its origin in the popliteal fossa, the anterior tibial artery gives off two arteries: the recurrent popliteal and the circumflex fibular arteries. The former of these ascends in front of the popliteus muscle of the knee joint, whereas the latter ascends and circles around the head of the fibula, the thinner of the two major bones of the lower leg. Upon crossing through the interosseus membrane, this artery then splits off into a number of branches, including:    

• Anterior tibial recurrent artery: Arising early in the course of the anterior tibial artery, the anterior tibial recurrent artery passes upward through the tibialis anterior muscle (an important muscle of the upper two-thirds of the tibia).  
• Perforating branches: Moving behind the extensor digitorum longus, a feather-shaped muscle of the anterior compartment of the leg, these branches pierce deep tissues (also known as fascia) on their way to the skin of the lower leg.
• Muscular branches: A number of small arteries branch off the anterior tibial artery that supply the muscles of the lower leg.
• Medial malleolar artery: Connecting with the posterior tibial artery, this artery emerges about 5 centimeters (cm). above the ankle joint, passing behind ankle tendons to terminate at the inner ankle.
• Lateral malleolar artery: This artery passes beneath the tendons of extensor digitorum longus as well as the fibularis tertius, a muscle of the front of the lower leg (shin). It eventually joins up with the peroneal artery.
• Dorsalis pedis artery: Once the anterior tibial artery reaches the front of the ankle, it becomes the dorsalis pedis artery, which runs to the top surface of the foot before splitting off into a number of its own branches.

Anatomical Variations

Like many other arteries and anatomical features, there are a couple of variations to the structure of the anterior tibial artery, though over 90% of people have no such differences. The most common of these is underdevelopment or even complete absence of this artery, in which case other arteries, usually the peroneal artery, make up the difference in terms of blood supply. Doctors have also observed rare cases where both the anterior tibial and posterior tibial arteries are absent, and, as above, alternative pathways are required for necessary blood to be delivered.  

Function

Primarily, the anterior tibial artery serves to deliver oxygenated blood to the front portion of the lower leg, which is called the “anterior crural compartment.” As such, and via its branches, it supplies nerve, muscular, and other tissues of the front of the lower-leg, as well as the skin. Towards its terminus in the front of the ankle, the branches of the dorsalis pedis artery ensure the structures of the top of the foot are supplied. Notably, examination of this artery can be essential in the doctor’s office. In clinical practice, one of the assessments for peripheral artery disease­—restriction or total blockage in arteries—requires doctors to palpate (apply pressure to) this artery.

Clinical Significance

Several diseases severely impact this artery, and care may involve everything from conservative measures such as lifestyle changes to surgery. Peripheral artery disease, characterized by a hardening of arteries due to build-up of plaques, can significantly impact anterior tibial artery function. The lack of blood flow caused by this disease, if it isn’t treated, can lead to gangrene (infection) and may even require amputation. If dietary and health adjustments don’t work in taking it on, doctors may employ angioplasty (the use of a specialized “balloon” inserted into the artery to open it up), the use of a catheter to remove a clot, or even bypass surgery.

Another significant set of issues that can afflict this artery are acute and chronic compartment syndrome, both of which are considered medical emergencies and require surgery to correct. Acute cases of this issue result either from blunt trauma to the area or after other musculature in the area experiences disruptions in blood flow. Chronic cases arise due to excessive exertion in the muscles and are sometimes called “exertional compartment syndrome.” In both cases, muscles in the anterior leg become inflamed, compressing the anterior tibial artery, and there may be internal bleeding, thus leading to a cascade of other symptoms. These include pain and swelling, and, significantly, surrounding nerves can become damaged leading to loss of muscular function.