One in four adults in the U.S. has adult acquired flatfoot deformity, which may begin during childhood or be acquired with age. The foot may be flat all the time or may lose its arch when the person stands. The most common and serious cause of flat foot is Posterior Tibial Tendon Dysfunction, in which the main tendon that supports the arch gradually weakens.
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.
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.
Although you can do the "wet test" at home, a thorough examination by a doctor will be needed to identify why the flatfoot developed. Possible causes include a congenital abnormality, a bone fracture or dislocation, a torn or stretched tendon, arthritis or neurologic weakness. For example, an inability to rise up on your toes while standing on the affected foot may indicate damage to the posterior tibial tendon (PTT), which supports the heel and forms the arch. If "too many toes" show on the outside of your foot when the doctor views you from the rear, your shinbone (tibia) may be sliding off the anklebone (talus), another indicator of damage to the PTT. Be sure to wear your regular shoes to the examination. An irregular wear pattern on the bottom of the shoe is another indicator of acquired adult flatfoot. Your physician may request X-rays to see how the bones of your feet are aligned. Muscle and tendon strength are tested by asking you to move the foot while the doctor holds it.
Non surgical Treatment
A painless flatfoot that does not hinder your ability to walk or wear shoes requires no special treatment or orthotic device. Other treatment options depend on the cause and progression of the flatfoot. Conservative treatment options include making shoe modifications. Using orthotic devices such as arch supports and custom-made orthoses. Taking nonsteroidal anti-inflammatory drugs such as ibuprofen to relieve pain. Using a short-leg walking cast or wearing a brace. Injecting a corticosteroid into the joint to relieve pain. Rest and ice. Physical therapy. In some cases, surgery may be needed to correct the problem. Surgical procedures can help reduce pain and improve bone alignment.
Surgical correction is dependent on the severity of symptoms and the stage of deformity. The goals of surgery are to create a more functional and stable foot. There are multiple procedures available to the surgeon and it may take several to correct a flatfoot deformity. Usually surgical treatment begins with removal of inflammatory tissue and repair of the posterior tibial tendon. A tendon transfer is performed if the posterior tibial muscle is weak or the tendon is badly damaged. The most commonly used tendon is the flexor digitorum longus tendon. This tendon flexes or moves the lesser toes downward. The flexor digitorum longus tendon is utilized due to its close proximity to the posterior tibial tendon and because there are minimal side effects with its loss. The remainder of the tendon is sutured to the flexor hallucis longus tendon that flexes the big toe so that little function is loss.