Most flat feet are not painful, particularly those flat feet seen in children. In the adult acquired flatfoot, pain occurs because soft tissues (tendons and ligaments) have been torn. The deformity progresses or worsens because once the vital ligaments and posterior tibial tendon are lost, nothing can take their place to hold up the arch of the foot. The painful, progressive adult acquired flatfoot affects women four times as frequently as men. It occurs in middle to older age people with a mean age of 60 years. Most people who develop the condition already have flat feet. A change occurs in one foot where the arch begins to flatten more than before, with pain and swelling developing on the inside of the ankle. Why this event occurs in some people (female more than male) and only in one foot remains poorly understood. Contributing factors increasing the risk of adult acquired flatfoot are diabetes, hypertension, and obesity.
There are numerous causes of acquired Adult Flatfoot, including, trauma, fracture, dislocation, tendon rupture/partial rupture or inflammation of the tendons, tarsal coalition, arthritis, neuroarthropathy and neurologic weakness. The most common cause of acquired Adult Flatfoot is due to overuse of a tendon on the inside of the ankle called the posterior tibial tendon. This is classed as - posterior tibial tendon dysfunction. What are the causes of Adult Acquired flat foot? Trauma, Fracture or dislocation. Tendon rupture, partial tear or inflammation. Tarsal Coalition. Arthritis. Neuroarthropathy. Neurological weakness.
As different types of flatfoot have different causes, the associated symptoms can be different for different people. Some generalized symptoms are listed. Pain along the course of the posterior tibial tendon which lies on the inside of the foot and ankle. This can be associated with swelling on the inside of the ankle. Pain that is worse with activity. High intensity or impact activities, such as running and jumping, can be very difficult. Some patients can have difficulty walking or even standing for long periods of time and may experience pain at the inside of the ankle and in the arch of the foot. Feeling like one is ?dragging their foot.? When the foot collapses, the heel bone may shift position and put pressure on the outside ankle bone (fibula). This can cause pain in the bones and tendons in the outside of the ankle joint. Patients with an old injury or arthritis in the middle of the foot can have painful, bony bumps on the top and inside of the foot. These make shoe wear very difficult. Sometimes, the bony spurs are so large that they pinch the nerves which can result in numbness and tingling on the top of the foot and into the toes. Diabetic patients may not experience pain if they have damage to their nerves. They may only notice swelling or a large bump on the bottom of the foot. The large bump can cause skin problems and an ulcer (a sore that does not heal) may develop if proper diabetic shoe wear is not used.
Clinicians need to recognize the early stage of this syndrome which includes pain, swelling, tendonitis and disability. The musculoskeletal portion of the clinical exam can help determine the stage of the disease. It is important to palpate the posterior tibial tendon and test its muscle strength. This is tested by asking patient to plantarflex and invert the foot. Joint range of motion is should be assessed as well. Stiffness of the joints may indicate longstanding disease causing a rigid deformity. A weightbearing examination should be performed as well. A complete absence of the medial longitudinal arch is often seen. In later stages the head of the talus bone projects outward to the point of a large "lump" in the arch. Observing the patient's feet from behind shows a significant valgus rotation of the heel. From behind, the "too many toes" sign may be seen as well. This is when there is abducution of the forefoot in the transverse plane allowing the toes to be seen from behind. Dysfunction of the posterior tibial tendon can be assessed by asking the patient to stand on his/her toes on the affected foot. If they are unable to, this indicates the disease is in a more advanced stage with the tendon possibly completely ruptured.
Non surgical Treatment
Flatfoot can be treated with a variety of methods, including modified shoes, orthotic devices, a brace or cast, anti-inflammatory medications or limited steroid injections, rest, ice, and physical therapy. In severe cases, surgery may be necessary.
Surgical intervention for adult acquired flatfoot is appropriate when there is pain and swelling, and the patient notices that one foot looks different than the other because the arch is collapsing. As many as three in four adults with flat feet eventually need surgery, and it?s better to have the joint preservation procedure done before your arch totally collapses. In most cases, early and appropriate surgical treatment is successful in stabilizing the condition.