Flatfoot, or Collapsed Arch

What is flatfoot, or flat feet?

Feet come in all shapes and sizes, and arch height is a bell curve whereby some people have low arched feet and some have high arched.  Having flat feet is not necessarily a problem, and “flat foot” is not a disease at all. Many people live their entire life with flat feet and never have any issues.  But a collapsed arch, meaning an arch that is losing height over time, is not normal.

What causes flat feet, or collapsed arches?

Diagram of the posterior tibial tendon

The posterior tibial tendon attaches the calf muscle to the bones on the inside of the foot. Image courtesy of AAOS.

The posterior tibial tendon is a tendon that runs on the inside of the ankle; it helps to put your foot in the right position so that the Achilles tendon can effectively power your gait forward. In order to do this, it must pull up slightly on the arch so that the foot is placed in a more rigid position. In some people, for reasons that are not always clear, the tendon can wear out over time, or it can be injured.  The “wearing out” of this tendon often causes some degeneration that can be difficult to heal. A deficient tibial tendon will lead to arch collapse over time.

How are flat feet, or collapsed arches treated?

The initial treatment for this problem typically involves attempting to create a healthier mechanical environment for this tendon.  An orthotic (arch support) is often used in an effort to take advantage of the fact that many flat feet tend to be flexible, and so the orthotic will typically push the arch up so that the posterior tibial tendon does not have to work as hard to do its job.  Physical therapy can be used as well to try to both strengthen the posterior tibial tendon and muscle, while also stretching out the calf muscle which is the primary force that works against the tendon; this treatment is often, although not always, successful.

When is surgery indicated?

If this treatment combination does not work well enough to improve the pain, then surgery can be considered. Surgery for flat feet is somewhat like the a la carte menu at a restaurant in the sense that there are several smaller operations that can be put together with each smaller one meant to address one aspect of the problem.  A tendon transfer is often used to a get new healthier tendon to perform the function of the posterior tibial tendon; and the bones of the foot can be shifted to build up the arch.  The details of the surgery can vary a lot from one foot to another.  A partial release of the calf muscle is often considered as well to minimize the pull from the calf.  Surgery of this nature is no small undertaking, although consistent good results are an expected outcome.