Overview 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. Causes Posterior tibial tendon dysfunction is the most common cause of acquired adult flatfoot deformity. There is often no specific event that starts the problem, such as a sudden tendon injury. More commonly, the tendon becomes injured from cumulative wear and tear. Posterior tibial tendon dysfunction occurs more commonly in patients who already have a flat foot for other reasons. As the arch flattens, more stress is placed on the posterior tibial tendon and also on the ligaments on the inside of the foot and ankle. The result is a progressive disorder. Symptoms Patients will usually describe their initial symptoms as "ankle pain", as the PT Tendon becomes painful around the inside of the ankle joint. The pain will become more intense as the foot flattens out, due to the continued stretching and tearing of the PT Tendon. As the arches continue to fall, and pronation increases, the heel bone (Calcaneus) tilts into a position where it pinches against the ankle bone (Fibula), causing pain on both the inside and outside of the ankle. As the foot spends increased time in a flattened, or deformed position, Arthritis can begin to affect the joints of the foot, causing additional pain. Diagnosis Diagnostic testing is often used to diagnose the condition and help determine the stage of the disease. The most common test done in the office setting are weightbearing X-rays of the foot and ankle. These assess joint alignment and osteoarthritis. If tendon tearing or rupture is suspected, the gold standard test would be MRI. The MRI is used to check the tendon, surrounding ligament structures and the midfoot and hindfoot joints. An MRI is essential if surgery is being considered. Non surgical Treatment Orthotic or anklebrace, Over-the-counter or custom shoe inserts to position the foot and relieve pain are the most common non-surgical treatment option. Custom orthotics are often suggested if the shape change of the foot is more severe. An ankle brace (either over-the-counter or custom made) is another option that will help to ease tendon tension and pain. Boot immobilization. A walking boot supports the tendon and allows it to heal. Activity modifications. Depending on what we find, we may recommend limiting high-impact activities, such as running, jumping or court sports, or switching out high-impact activities for low-impact options for a period of time. Ice and anti-inflammatory medications. These may be given as needed to decrease your symptoms. Surgical Treatment Stage two deformities are less responsive to conservative therapies that can be effective in mild deformities. Bone procedures are necessary at this stage in order to recreate the arch and stabilize the foot. These procedures include isolated fusion procedures, bone grafts, and/or the repositioning of bones through cuts called osteotomies. The realigned bones are generally held in place with screws, pins, plates, or staples while the bone heals. A tendon transfer may or may not be utilized depending on the condition of the posterior tibial tendon. Stage three deformities are better treated with surgical correction, in healthy patients. Patients that are unable to tolerate surgery or the prolonged healing period are better served with either arch supports known as orthotics or bracing such as the Richie Brace. Surgical correction at this stage usually requires fusion procedures such as a triple or double arthrodesis. This involves fusing the two or three major bones in the back of the foot together with screws or pins. The most common joints fused together are the subtalar joint, talonavicular joint, and the calcaneocuboid joint. By fusing the bones together the surgeon is able to correct structural deformity and alleviate arthritic pain. Tendon transfer procedures are usually not beneficial at this stage. Stage four deformities are treated similarly but with the addition of fusing the ankle joint.