Leg – Arterial Supply

What we’re looking at here is a posterior view of the knee and the leg, and we can see the popliteal artery running behind the knee joint and it gives off two branches. You’ve got the posterior tibial artery, which you can see here in red. And if I rotate the model around slightly, you can see the anterior tibial artery in purple. So the posterior tibial artery gives off the peroneal, or fibular artery, which you can see here. Now the bit between the origin of the anterior tibial and the origin of the fibular artery, is sometimes referred to as the tibioperoneal trunk, or the tibioperoneal trunk. So this tibiofibular trunk gives off the fibular artery and the posterior tibial artery.

Now to begin with let’s take a look at the branches of the anterior tibial artery. So you can see it here in this model in purple, and it arises just below the inferior border of the popliteus muscle. And rotating the model around you can see how it enters into the anterior, or extensor compartment of the leg, just above the interosseus membrane. The branches of the anterior tibial artery include the posterior tibial recurrent, and the anterior tibial recurrent arteries proximally. The posterior tibial recurrent artery is not always present and its not shown on this model. The anterior tibial recurrent artery you can see here. I’ve just switched over to a different model, which illustrate how the anterior tibial recurrent artery anastomoses with the lateral inferior genicular branch of the popliteal. So if I rotate the model around you can see the lateral inferior genicular coming off the popliteal artery, and you can also see this other branch anastomosing, which is the circumflex fibular artery of the posterior tibial artery, which I’ll come back to talk about.

The anterior tibial artery runs down the length of the leg, along the interosseus membrane and then it gives off some distal branches as it approaches the ankle joint. It then terminates as the dorsalis pedis artery, which supplies the foot. So we’re looking at the ankle joint here and we can see some muscles of the extensor compartment. We’ve got the extensor digitorum longus muscle, the extensor hallucis longus muscles, and the tibialis anterior muscle.

So I’ve just zoomed in a little bit closer and you can see the distal branches, you’ve got the anterior medial malleolar artery and the anterior lateral malleolar artery. As well as the arteries I’ve just mentioned, there are also several muscular branches and perforating branches which come off the anterior tibial artery, to supply the muscles and the skin respectively.

Just looking from this anterior view of the ankle joint, you can see how the anterior tibial artery crosses the ankle joint, roughly midway between the medial and lateral malleoli.

Now coming back to the posterior tibial artery, let’s take a look at some of the branches. Proximally we’ve got the circumflex fibular artery which we looked at before. So this artery winds around the neck of the fibular and anastomoses with the lateral inferior genicular artery. The posterior tibial artery then descends posteriorly down the long and distally it gives off a few branches. There are some branches which come off to supply the medial malleolus, and then there’s also this branch which comes off called the communicating branch, which anastomoses with the communicating branch of the fibular artery, which you can see here. Coming even further distally, you can see another branch which comes off to supply the calcaneus, so there are also calcaneal branches.

The posterior tibial artery then terminates by dividing into the medial and lateral plantar arteries, to supply the plantar aspect of the foot. In addition to the branches I’ve just mentioned, there is also a nutrient artery of the tibia, which is given off by the posterior tibial, and there are also muscular and perforating branches.

Now returning proximally, the last artery to talk about is the fibular artery, or the peroneal artery. So the tibiofibular trunk divides into the posterior tibial and the fibular artery, or as some texts describe it, the posterior tibial artery gives off the fibular artery. So looking at the distal branches, the fibular artery, which you can see here gives off the communicating branch which anastomoses with the communicating branch of the posterior tibial, and then it also gives off this calcaneal branch and it also has branches which anastomose with the anterior tibial branches. So if I just rotate the model around anteriorly, you can see these branches which anastomose with the malleolar branches of the anterior tibial artery.

So that’s the arterial supply to the leg. Next we’ll look at the arterial supply to the foot.