Pes planus refers to a condition in the foot wherein the normal longitudinal arch is absent and the patient is weight bearing on the inside or medial border of the foot with the foot in a somewhat pronated and turned out position. There are many causes of flat feet and most of them are completely benign.
The most common complaint regarding flat feet usually comes from the parents who don’t like the appearance of it. Very rarely does a child experience any difficulties. Occasionally a patient will present with painful flat feet and that warrants further investigation. In the painful flat foot, symptoms may include recurrent sprains of the ankle or painful calluses over the medial border of the Plantar Fasciitis surface of the foot. Confining shoe wear is also a common complaint.
The key to diagnosis in flat foot problems is to determine whether or not the pes planus is flexible or rigid. Flexible flat foot rarely causes significant difficulty for the patient and is usually treated conservatively by careful shoe wear selection and occasional addition of soft arch supports. A flexible flat foot will reconstitute a nice arch when standing on tiptoe or in stance phase, by elevating the first metatarsophalangeal joint. This is a so-called joint jack test and when the great toe is flexed up towards the ceiling, medial arch reappears on the foot. In addition, a flexible flat foot has a supple subtalar motion. In the rigid flat foot, all of the previously mentioned signs are absent. The subtalar range of motion is stiff and restricted and the arch does not reconstitute when standing on tiptoe or performing the joint jack test. In all cases of foot problems, a careful neurological exam needs to be done as well, and of course in flexible flat foot, is universally normal.
Flexible flat feet, as mentioned previously, require supportive treatment only and has a completely benign natural history. In a rigid flat foot the treatment needs to be directed towards the underlying problem. Occasionally conditions such as tarsal coalition can be present. This refers to a condition when one or more bones in the foot are abnormally fused together. In younger patient’s, surgery may be performed to remove the fusion between the involved bones. If the case is more advanced or the patient is older, then realignment osteotomies and fusions of the foot may be indicated. Sometimes if the condition is mild and underlying problems are not so severe, supportive treatment with anti-inflammatory medication and the use of custom orthotics or shoe inserts may be all that is needed.