Flat feet and other structural problems

Flat foot is a common condition and for many people with flat feet, the condition does not cause any problems or symptoms.

The foot is a complex structure with 28 bones and 26 joints. It also takes all the load of body weight when standing, walking and running and it is it therefore not surprising that it is prone to deformity.

Causes

Feet can be abnormally shaped from birth (eg club foot) or can become deformed and this can happen at any stage in the life of a foot. The shape of the foot is determined by your genes but also by the shape of the bones, the supporting ligaments and the muscles and tendons that move the foot.

Problems related to structural disorders

As a result, abnormally shaped bones (including broken bones), ligament injuries, disorders of nerves supplying the muscles and abnormalities of the muscles and tendons themselves can lead to misshapen or deformed feet.

Flat feet and high-arched feet

Flat feet

Image of patient with flat feet

A flat foot is one where the main arch on the inside of the foot sags, and this can be mild to severe in its extent. Often an individual with a flat foot lives a completely normal life without ever knowing that the foot is “flat”.

Flat feet are divided into physiological and pathological groups: the pathological flat foot has something structurally wrong with it, whereas a physiological flat foot is essentially normal in terms of anatomy but is just rather flat.

High-arched feet

Image of patient with high arches

The opposite condition is a high-arched foot (known as pes cavus) and is often, but not always, associated with a problem affecting the nerves to the foot.

Structural foot disorders and pain

A foot that is deformed is mechanically at a disadvantage compared with a normal foot. Although the deformity may not be painful, the abnormal foot is more vulnerable to the stresses and strains to which it is subjected on a day to day basis. It is therefore more likely to become painful with time.

The two common causes of an acquired painful flat foot are:

  1. Inflammation and degeneration of the tibialis posterior tendon, which is a tendon that passes to the foot on the inside of the ankle. The symptoms are of pain and swelling and gradual flattening of the foot. It is often missed and left untreated can cause major disability.
  2. Arthritis of the joints below and in front of the ankle. The commonest joints affected are the ones in the middle of the foot (tarso-metatarsal joints) and the one below the ankle (the subtalar joint). These joints can become arthritic as a result of an inflammatory joint condition, following injury or most commonly due to “wear and tear”. The symptoms are those of pain on weight bearing and gradual deformity with time.

In children, a so-called tarsal coalition where two bones of the foot are joined together from birth often presents in early teens with pain and stiffness but can present with recurrent ankle sprains.

Coalitions are often associated with a stiff flat foot deformity. Sometimes the coalition does not cause problems until adulthood and usually there is a family history of similarly affected relatives.

Diabetic patients and foot disorders

Diabetic patients, especially those with the disease for many years, can develop a painless flat foot deformity very rapidly when a so-called “Charcot” process takes place. The foot becomes red and very swollen and this condition needs to be treated and recognised early on to avoid disastrous consequences later.

Whatever the deformity, whether it is a flat foot, high arch or some other configuration, it is important for the underlying cause to be diagnosed accurately. Anybody with a deformed or deforming foot should see an orthopaedic surgeon specialising in foot and ankle disorders for a diagnosis.

Treatment

Non-surgical treatment

Many patients with structural deformity need surgery but some deformities need no treatment other than observation and some feet will need footwear modification.

Innersoles can help support a stiff foot but cannot change the shape, whereas flexible deformities can be corrected with appropriate innersoles or orthoses.

Physiotherapy can help stretch tight muscles but can not correct rigid deformed feet. Surgery has a lot to offer patients with foot deformity and the operations usually involve making the foot look more normal. Such a foot will withstand the rigours of day to day life more than a deformed one.

Surgical treatment

For many people surgery for flat feet and other structural deformities has a lot to offer. Surgery combines tendon transfers, reshaping bones, fusing joints and releasing contractures of soft tissue.

Patients are almost invariably treated thereafter in a plaster for a limited period followed by lots of physiotherapy to optimise the final outcome of surgery. The results of such surgery are usually very successful allowing the patient to resume normal activities and wear normal shoes which prior to surgery they were unable to do.