Have you sprained your ankle? Do you have a flat foot that seems to be giving you pain? Any really bad fractures in the past? These and a few other things can lead to pain that my patient’s come in calling ‘ankle pain.’ Each of our feet has 28 bones in it. That’s a lot for a smaller part of our body, but the reason is because our foot has to transfer all of the energy from the ground through the rest of our body and also has to help propulse our body in order to walk. So each foot has to have multiple areas of mobility. Each place where one bone in our foot contacts another is called a joint, so therefore there are also many joints in our feet.
Our true ankle joint is made up of actually 3 bones-the tibia (or shin bone), the fibula (or the outer leg and ankle bone) and the talus (which usually people haven’t heard of). The ankle joint is primarily in control of the straight up and down movement of the foot in relation to your leg. The side-to-side motion that you have is actually happening at another joint in our foot called the subtalar joint. This joint is essentially one joint below the ankle joint.
If you have injured your foot in the past or if you have inherited one of a few certain foot types, this subtalar joint can sometimes be the culprit of what you perceive as “ankle pain.” The subtalar joint is made up of your talus (see above) and the calcaneus – or heel bone. This joint has a less than typical shape to it. It is nothing like the saddle shaped ankle joint and also very different from the joints in the ball of the foot. It also is not exactly a continuous joint. There are a few different contact points that comprise the subtalar joint and we call these facets. These are smoother portions of contact between the calcaneus and talus and are covered with cartilage (as any other joint would be). The anterior and medial facets are on the part of the subtalar joint that is closer to the toes and the posterior facet is at the back of the joint. In between these is an area referred to as the sinus tarsi – think of it as a valley of sorts.
Not that you have to memorize the anatomy provided here – but you get the idea that it is a more complex and interesting joint than you may have realized you have in your foot. Now onto why we should care about our subtalar joint…
One condition that can lead to pain in this subtalar joint is flatfoot. Having a foot structure that is flexibly flat (flattens out more when you stand on it) means that there is more motion through this joint than in a foot that is ‘normal’ in this way. So with more motion, there can be irritation or even damage over time that occurs to the valley within the subtalar joint (sinus tarsi). This is a condition that we refer to as sinus tarsi syndrome. When there is pain here, you may well perceive it as ankle pain. Initial treatments for sinus tarsi syndrome are similar to the treatment for ankle joint pain. However, if simple conservative measures do not improve your pain and an injection is recommended, it matters quite a bit where the medicine is delivered.
In instances of previous injuries, whether having twisted your ankle (recently or decades ago) or suffering a sprain or fracture in your ankle or heel bone, arthritis and pain can occur in the subtalar joint. Of course, at the time of your injury, the focus in both of these instances would be elsewhere. Though the subtalar joint often has suffered some degree of injury at the same time which may go undiagnosed. Over time, arthritis in the subtalar joint causes pain as it would in any other joint but again can be mistaken for ankle pain.
Another condition that we as physicians will evaluate for when there is pain associated with the subtalar joint is something called a coalition. A coalition when speaking anatomy refers to a connection between two bones where there should be a joint. This connection can be made of cartilage, fibrous tissue or even bone. Again, there are certain foot types that are more commonly associated with coalitions. The coalition can occur at any of the facets within the subtalar joint. In most cases, when there is a coalition in the subtalar joint, it only affects one of the facets mentioned earlier. This leads to uneven distribution of weight and increased motion at the remaining two facets which causes damage to those joints over time.
Differentiating between ankle and subtalar joint pain starts with a thorough physical exam by your podiatrist. The exam helps us to localize the location of pain and can tell us whether motion at the ankle, subtalar or both joints is present. Evaluating your gait (watching you walk) can give us clues as well. We also get an initial perspective on your foot structure through this exam. If there was an old injury (or fracture) then arthritic changes may be seen on x-rays. If a coalition is suspected, the appropriate x-rays can often reveal a coalition directly. If there is no coalition noted on x-rays and no arthritis, then diagnostic injections or MRI can be useful tools.
In treating subtalar joint pain, initial therapies are aimed at immobilizing or resting the subtalar joint through use of a brace or boot. Bringing the inflammation down with icing and in some instance the use of oral anti-inflammatories is important as well. In some instances, physical therapy or injections can be used. Ideally, these initial therapies will help to alleviate the acute pain and then our focus is on supporting the foot in a way to reduce the stress to the subtalar joint and to balance the joints in efforts to reduce or slow progression of arthritis. Conservatively, the consistent use of custom orthotics is incredibly helpful. Surgery for subtalar joint pain is at times necessary and the type of surgery depends greatly on each individuals condition.
So if you feel like you have ankle pain, it may be that – though it could also be your subtalar joint. If you have pain in your feet in any area, this is not a normal thing. Don’t put off treating this pain, as the longer treatment is delayed the more difficult it is to resolve. Call for an appointment today!