There is no indication for treatment in a physiological painless flat foot. Orthotics in the form of an arch support may ease aching but are unlikely to make the arch develop.

Several operations have been developed to reconstruct the arch. These include tightening of the lax tendons on the medial side of the foot and lengthening or fusing the hindfoot bones (calcaneum, talus). These operations can run a risk of converting a painless flat foot into a painful foot with an arch. For this reason such surgery is usually reserved for extreme cases.

More recently there has been a vogue for inserting implants into the collapsed (subtalar) hindfoot joint in order to ‘jack’ the joint open. To date such surgery (sinus tarsi implants) has to be considered experimental although early results are encouraging in carefully selected children.

One of the most frequent causes of ‘pathological’ flat foot is tarsal coalition. This describes an abnormal connection between the bones within the foot. The commonest coalitions are between the navicular bone and the calcaneum, and the talus and calcaneum. Patients usually present in their early teens with stiff and often painful flat feet. Diagnosis is often made on plain X ray but the extent of the coalition is more accurately measured with Ct scans or MRI.

Some coalitions (particularly navicular-calcaneum) can be easily removed surgically.