Often considered solely a product of genetics, flatfoot rarely carries with it the stigma of presenting over time. The truth, however, is that flatfoot does not discriminate on the basis of age and can become an issue in the form of adult-acquired flatfoot. Like its congenital cousin, adult-acquired flatfoot deformity is one that, in causing structural damage to the foot (and particularly to the posterior tibial tendon), creates an imbalance that may result in any number of symptoms, including inflammation, pain, stiffness, limited mobility, and even arthritis.
Adult acquired flatfoot is caused by inflammation and progressive weakening of the major tendon that it is responsible for supporting the arch of the foot. This condition will commonly be accompanied by swelling and pain on the inner portion of the foot and ankle. Adult acquired flatfoot is more common in women and overweight individuals. It can also be seen after an injury to the foot and ankle. If left untreated the problem may result in a vicious cycle, as the foot becomes flatter the tendon supporting the arch structure becomes weaker and more and more stretched out. As the tendon becomes weaker, the foot structure becomes progressively flatter. Early detection and treatment is key, as this condition can lead to chronic swelling and pain.
Symptoms of pain may have developed gradually as result of overuse or they may be traced to one minor injury. Typically, the pain localizes to the inside (medial) aspect of the ankle, under the medial malleolus. However, some patients will also experience pain over the outside (lateral) aspect of the hindfoot because of the displacement of the calcaneus impinging with the lateral malleolus. This usually occurs later in the course of the condition. Patients may walk with a limp or in advanced cases be disabled due to pain. They may also have noticed worsening of their flatfoot deformity.
The adult acquired flatfoot, secondary to posterior tibial tendon dysfunction, is diagnosed in a number of ways with no single test proven to be totally reliable. The most accurate diagnosis is made by a skilled clinician utilizing observation and hands on evaluation of the foot and ankle. Observation of the foot in a walking examination is most reliable. The affected foot appears more pronated and deformed compared to the unaffected foot. Muscle testing will show a strength deficit. An easy test to perform in the office is the single foot raise. A patient is asked to step with full body weight on the symptomatic foot, keeping the unaffected foot off the ground. The patient is then instructed to "raise up on the tip toes" of the affected foot. If the posterior tibial tendon has been attenuated or ruptured, the patient will be unable to lift the heel off the floor and rise onto the toes. In less severe cases, the patient will be able to rise on the toes, but the heel will not be noted to invert as it normally does when we rise onto the toes. X-rays can be helpful but are not diagnostic of the adult acquired flatfoot. Both feet - the symptomatic and asymptomatic - will demonstrate a flatfoot deformity on x-ray. Careful observation may show a greater severity of deformity on the affected side.
Non surgical Treatment
Treatment will vary depending on the degree of your symptoms. Generally, we would use a combination of rest, immobilization, orthotics, braces, and physical therapy to start. The goal is to keep swelling and inflammation under control and limit the stress on the tendon while it heals. Avoidance of activities that stress the tendon will be necessary. Once the tendon heals and you resume activity, physical therapy will further strengthen the injured tendon and help restore flexibility. Surgery may be necessary if the tendon is torn or does not respond to these conservative treatment methods. Your posterior tibial tendon is vital for normal walking. When it is injured in any way, you risk losing independence and mobility. Keep your foot health a top priority and address any pain or problems quickly. Even minor symptoms could progress into chronic problems, so don?t ignore your foot pain.
A new type of surgery has been developed in which surgeons can re-construct the flat foot deformity and also the deltoid ligament using a tendon called the peroneus longus. A person is able to function fully without use of the peroneus longus but they can also be taken from deceased donors if needed. The new surgery was performed on four men and one woman. An improved alignment of the ankle was still evident nine years later, and all had good mobility 8 to 10 years after the surgery. None had developed arthritis.