FLAT TOP TALUS

PROPER DIAGNOSIS IS THE KEY

This refers to the flattened shape on the top of the talus bone. The talus is a bone that connects the leg bones to the foot bones so clearly its very important. The talus has a flat bottom surface that makes up the subtalar joint and a dome on its top surface which makes up the ankle joint. The condition of flat top talus refers to the top dome surface of the bone losing its dome shape. The dome shape is important since it directly effects how much motion an ankle joint will have – both up ( toes to your nose – dorsiflexion) and pointing down (plantarflexion). Generally the flatter that dome the less ankle motion one may have. Of course there are other factors that may effect this range of motion but the shape of that bone may be the biggest.

What is flat top talus?

FTT is a rare condition that we usually find in patients who were born with some sort of clubfoot or equinus contraction of the ankle. Also in most cases these patients had some sort of treatment – either casting and manipulation or surgery.

How does a doctor diagnose it?

Generally xrays will give the best indication of the shape of the dome, a CT scan may help but is does expose the patient to a significant amount of radiation so we only use it in specific cases. Doing the xrays properly is the key and what we find most doctors consistently get wrong.

Does a flat top talus hurt?

Interestingly enough , in many cases patients have no pain even though the contours of the joint are deformed. As the patient gets older arthritis may set in and create symptoms in the ankle joint. Many times the patient is seen because of a deformity where another part of the foot is painful because of the motion limitation at the ankle joint. Usually they lose ability to dorisflex the ankle joint – bring toes up to the nose or move the foot up. In many cases this leads to walking on toes and an increased pressure on the ball of the foot which can be quite painful over time.

Does a flat top talus ankle move at all?

We have found that even an almost completely flat talus dome may still have motion but not exactly as one may expect from a joint. The normal ankle joint anatomy is set up so that the joint can rotate up and down. In flat talus the joint can move but does not rotate , it may just open like a door hinge.

How does a surgeon fix Flat Top Talus condition?

There are two ways to deal with it. If the joint itself has arthritis and paitn has pain we may consider an ankle fusion or a joint cleanup if we think that may give some relief. In cases where we want to preserve the joint range of motion since in many patient even the small motion thay get from this joint may be the only motion they have in the foot. We can try to cut the bones around the ankle joint to realign the foot and not touch the ankle at all. These are called ‘joint sparing procedures ‘ in the medical journals.  These are done using bone osteotomy or fusion of other joints to realign the entire foot. Two major reconstructive procedures to deal with significant foot deformity with flat top talus are the ilizarov U osteotomy and V osteotomy which happen to be our specialty. These are ankle joint sparing procedures done with external fixation allowing us to realign the foot and ankle with minimal incision using external fixation. This also allows us to lengthen a leg of make a foot taller if needed by growing new bone. These procedures are used in more significant deformity cases and allow us not to rely on bone grafting or the limitations of internal fixation like screws and plates. As far as we know Dr. Gitlin is one of the only foot and ankle surgeons  with experience in the ilizarov U and V osteotomy with the classic kurgan technique- the way it was originally intended to be done with minimal incision and allowing the patient to walk immediately after surgery.