Surgery scheduled

Note: this post is updated regularly as I learn more.

I met with a orthopedic surgeon today who specializes in foot and ankle surgery. For the first time I had a doctor talk to me about other procedures that need to be done besides just the subtalar fusion that had always been recommended to me.

One of my main concerns about the fusion surgery was that it may not correct the position of my heel. Doctors had always said something like "We'll just complete the fusion." This never sounded "corrective" to me.

It was explained to me today that, if it is possible, the coalition will be broken apart and the heel bone will be moved to a more optimal position before fusion. That made me feel a ton better. Hopefully that will prevent the twisting sensation I feel when I walk. If they cannot move the calcaneous (heel) bone, it will need to be cut in half and repositioned (a calcaneal osteotomy). Apparently there are lots of nerves and arteries under the subtalar joint that limit how far you can move the calcaneous. My surgeon referred to this as an area of "major badness." I'll take his word for it.

But there are some other things the surgeon will do. Apparently my forefoot has compensated for my heel being misaligned. Once the heel is repositioned, my forefoot will be twisted (supinated) which may require more surgery. In order to compensate, the surgeon is recommending a lateral column lengthening (involving the calcaneous bone) and also a Cotton Osteotomy on a cuneiform. These involve wedging a bone graft into strategic areas to move things into the proper position. The achilles tendon will receive a small incision below my calf muscle. This releases some tension here to compensate for any tightening resulting from the heel mocement.. This will all be done at the same time as the subtalar fusion. I think I counted a total of 4-6 separate incision points.

The subtalar fusion will be the same as you read about everywhere else. Bone grafts and screws. The doctor said I will be non-weight bearing (crutches) for at least six weeks. After that I will gradually start to put weight back on the foot.

Click image to enlarge.

If you have tarsal coalition and are considering surgery, try to find a foot and ankle specialist. I have been to a few orthopedic surgeons and they each told me they had done the surgery a "few" times, which scared me a little. When I asked the specialist today how familiar he was with this surgery, he said he makes these type of corrections "all the time." So don't be afraid to quiz your doctors.

Radiology

I was able to get a copy of my X-rays from my podiatrist. I've posted here, as well as the report from my CT scan. I've noted a few things of interest on the X-rays. First is what is called the C-sign (white arrows), named because of the shape of the formation. I'm still researching what causes this. Next is the area of the coalition, which in my case is the middle facet between the talus and the calcaneous (red arrow). This is hard to see. Third is what is called beaking (because it looks like a beak). It's visible between the talus and the navicular (yellow arrow). Talar beaking is common with subtalar coalition. I'm looking into what causes beaking and if it's a source of pain. It sure looks like it is. Also, it's worth noting how much shorter the talus is in the left (coalition) foot than in the right.

If you're really interested, here is the radiology report from my left foot CT scan:
There is talocalcaneal coalition at the sustentaculum tali / middle talocalcaneal facet. The posterior talocalcaneal facet and anterior articulation appear preserved. There is dorsal talar beaking, foreshortening of the anterior talar process and dorsal navicular beaking all in a pattern typical for subtalar coalition. The ankle mortise is intact. There is foreshortening of the medial malleolus, also typical for subtalar coalition. The calcaneal cuboid joint, navicular cuneiform joints and all three intercuneiform joints are unremarkable. The Lis Franc joints are normal in appearance. The remaining osseous structures are unremarkable.

Flat feet

In “Why does it hurt?” I illustrated how the coalition causes the arch of my foot to collapse. I wanted to include one more picture. This is my “Charlie Chaplin” photo. I don’t actually stand like this, it’s two pictures put together.


The white lines show the distance from where my heel touches the ground to where the top of my arch is. I’ve also included a redline to show the difference between my ankles. This can cause problems all the way up the leg. I have tired legs and frequent back trouble. It’s either from this or I’m just getting old.

Now it’s important to know that there are two types of flat feet: flexible and rigid. Flexible flat feet can be treated with orthotics and inserts. These move the foot into the proper arch.

I’ve tried two kinds of orthotics for my feet. I hated them. I walked off the side of my shoes and they were painful. It is common to try orthotics for flat feet from tarsal coalition. And I’ll leave it to the experts to decide whether or not use them. But when you think about it, how does an orthotic help a rigid flat foot?

My orthotics twisted my leg until I had a condition in my knees called sublux patella. It had to be corrected with surgery. If your doctor is recommending this, quiz him or her about it. Sometimes orthotics and special shoes are not covered by health insurance so be careful what you spend your money on.

Why does it hurt?

When functioning properly, your foot forms a tripod, which is a stable foundation for your body. As you take a step, your heel actually moves from side to side. It moves to where it makes the tripod most stable.

When your heel has moved to the pinky toe side of the foot it is said to be in the valgus position. When it has moved to the big toe side it is said to be in the varus position.

In a foot that involves a coalition of the calcaneous (heel bone) with another bone, it is locked into the valgus position. This makes the tripod off center and the arch of the foot collapses. If you have a coalition, you have a flat foot.


In this image, I attempt to illustrate the tripod concept. Remember, my right foot is normal. When someone looks at the image on the left, they may think that the feet are completely normal. But if you look closely, you can see the heel of my right (normal) foot, but not my left (coalition) foot. You can also begin to see how my left (coalition) foot is "rolling" inward which makes my arch disappear. On the right I've drawn some tripods. You can see how the tripod of my right (normal) foot is stable. However, the the heel of my left foot is stuck in the valgus position which causes the point of the tripod to buckle (red arrow).

This instability causes all kinds of trouble. Tendons and other tissues get pulled and twisted abnormally which can cause a burning sensation on the top/outside of your foot. The muscle and tissue along the arch of your foot gets stretched and can spasm. The joint itself takes on a lot more stress than it's intended to.

You may also have some very deep pain, I know I do. That little bony bridge, the coalition, gets a ton of torque on it. The twisting and torquing can cause an bone marrow edema (collection of fluid) to form inside the bones themselves. A recent MRI revealed edema in my left foot.

What is tarsal coaltion?

Tarsal coalition is a union (or coalition) of two or more bones in the hind foot or mid foot. The bones of the mid and hind foot are collectively known as the tarsals.

It can be a congenital defect, which means it’s existed since birth. Sometimes it can result from an injury to the foot.

If you’re like me, the coalition is the result of a birth defect. As you developed, before birth, the tarsals were part of a block of material that became the bones of your foot. As you grew the bones formed, split and hardened. A coalition formed when the split was incomplete. The resulting union can be bony (synostosis), cartilaginous (synchondrosis), or fibrous (syndesmosis).

In my case I have a talo-calcaneal coalition. The talus and calcaneous (heel bone) touch on three facets. I have a union of the mid facet. Learn more about foot anatomy.

Another common union is between the calcaneous and navicular. And sometimes there is a union between all three; talus, calcaneous and navicular.

Tarsal coalition can be genetic. My parents don’t appear to have it, and neither do my children. However I have had a great uncle and a nephew born with a club foot. I’m not sure there’s a correlation.

Anatomy Lesson

The human foot is pretty complex, and it can be difficult to visualize how every part fits together. But, I think it’s important to understand the anatomy of your foot, so that you have a better understanding of what tarsal coalition is and why it hurts.

This is not a complete anatomy, and I’ve simplified the language a bit to help you (and me) better understand what’s going on.


Your lower leg is made up of two bones. Your tibia (shin bone) and your fibula. Your outer ankle bone is actually the bottom of your fibula. Your inner ankle bone is the bottom of your tibia. These two bones rest atop the talus. The talus sits atop the calcaneous (heel bone). These two bones together make up your hind foot.

As we move forward from the hind foot we see the next two bones. The talus touches the navicular. The calcaneous (which sits just below and to the outside of the talus) touches the cuboid.

From the navicular we find three more bones called the cuneiforms.

The medial cuneiform (on the inside of your foot) serves as the base for the metatarsal that connects with the big toe. (The metatarsal are the bones of the foot which are kind of like the bones in the palm of your hand).

The intermediate cuneiform serves as the base for the metatarsal that connects with second toe.

The lateral cuneiform serves as the base for the metatarsal that connects with third toe.

The cuboid (which touches the calcaneous) serves as the base for the metatarsals that connects with fourth and fifth (pinky) toe.

These five bones (navicular, cuboid, and medial, intermediate and lateral cuneiforms) make up your mid foot.

There are five metatarsals which connect to one of your five toes. These and your toe bones make up your fore foot.

Introduction

Hey there, my name is Chris. I’m 35 years old (as of 2008) and have a condition in my left foot called tarsal coalition. Since my right foot is healthy, it makes it a little easier to see and understand what the difference is between a normal foot and a foot affected with tarsal coalition. I thought I’d put some images and text together on a blog to hopefully help other patients.

It’s taken me a while to understand exactly what’s up with my left foot. Hopefully this little blog will help you quickly answer some questions you may have. I will hopefully be having surgery soon, and will keep the blog updated on at least a weekly basis as that unfolds. Please feel free to comment, correct or add your thoughts.