Flatfoot is common on both children and adults. It is an often-misunderstood malady by both medical and lay people alike, due to the fact that there are many types of flatfoot as well as many presentations clinically. In this blog I will discuss the most common forms of pediatric flatfoot.
First there are two broad categories of flatfoot: flexible, and rigid. Rigid flatfoot is present at birth but progresses as the child ages and in many cases becomes painful. The foot is in an abnormal position both on and off weight bearing and is often visible even to the untrained eye that “something is abnormal”. The joints of the ankle, and hindfoot are usually immovable, or at least stiff. Below are some clinical pictures of a rigid flatfoot.
The two most common causes of rigid flatfoot are congenital vertical talus, (CVT) present at birth and usually visible on examination as well as plain Xray. The second common cause of rigid flatfoot is tarsal coalition. This is a connection between the bones of the hindfoot also present at birth. It often is not as obvious as CVT and is not detected until later in childhood or early adolescence due to its variability in clinical presentation. The child may only complain intermittently or not at all, but as they grow the foot tends to become more deformed and is often painful with more obvious deformity. Below are some clinical pictures of tarsal coalition with pictures of imaging as well. Often the coalition is not visible on plain X-ray and may require MRI to make the diagnosis or for surgical planning. Tarsal coalition often requires surgical intervention for satisfactory correction of the foot position as well as normal function and flexibility of the foot.
The third, and probably MOST common form of pediatric flatfoot is idiopathic flexible flatfoot. There is often a positive family history in these cases. The foot in this child appears “normal” when non weight bearing, but when weight bearing the arch may become extremely flat, more importantly is the heel position when viewing the child from behind. The heels will appear tilted outward. This heel position is called “valgus” and is a result of a contracture or abnormal shortening of the heel cord (Achilles Tendon), which is called “Equinus”. Below is a clinical presentation of a patient with idiopathic flexible flatfoot both on and off weight-bearing: there is a remarkable difference. Also included are plain X-rays showing the malalignment of the forefoot to the hindfoot.
The most intriguing thing about idiopathic flexible flatfoot is the variability in its clinical presentation as well as various treatment regimens. In many cases no treatment is indicated especially if the arch is flat but there is no “equinus”. On the other hand, if equinus; (short tendo-Achilles) is present, the foot often becomes progressively worse or becomes painful, especially as the child’s size activity level increases. This patient will need treatment with orthoses, shoe inserts, specifically designed, not simply to raise the arch, but more importantly to reposition the heel from the outward tilt (valgus) position to neutral vertical position. This requires a deep heel cup, rigidity, and often a “hindfoot post” which tilts the heel even more to correct it to a neutral position. Below is a clinical picture of a pediatric “UCBL” type device.
Finally, as I mentioned earlier the variability in idiopathic flexible flatfoot is wide, but there are a number of these cases which will require surgery to correct the deformity and restore normal foot position and foot function. Below are a few before and after X-rays.
Hopefully, this explains some of the mysteries of pediatric flatfoot in layman’s terms as there is great variability in its clinical presentation as you have seen from these examples.