The lateral tarsal artery branches off the dorsalis pedis artery as it crosses the navicular bone, located just in front of the ankle. This blood vessel delivers oxygenated blood to the tarsal region of the foot, an area comparable to the carpal region of the hand and wrist.
The tarsus is made up of many small bones near the joint of the ankle. The lateral tarsal artery is located between these small bones and the under the extensor digitorum brevis muscle, which it supplies with blood. For much of its course, the lateral tarsal artery runs in close proximity to the lateral terminal branch of the deep fibular nerve.
The lateral tarsal artery forms anastomoses (connections) with the perforating branch of the fibular artery and several others near the ankle joint. Unlike other blood vessels, the lateral tarsal artery does not possess a vena comitans of a similar name. (A vena comitans is a vein that has a close relationship with an artery, so that the pulsing of the artery helps move blood through the vein.)
Oxygen-depleted blood is drained from the foot and ankle by a variety of different veins but the foot is known to have poor circulation, relative to the rest of the human body. Because of this, some people develop osteonecrosis, or avascular necrosis. This is bone cell death, and therefore bone tissue death, that results from a lack of blood supply. Avascular necrosis can lead to small breaks in the bone and, eventually, collapse. There are many treatments for avascular necrosis, including osteoporosis drugs, physical therapy, and surgical procedures.