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.
Often, this condition is only present in one foot, but it can affect both. Adult acquired flatfoot symptoms vary, but can swelling of the foot's inner side and aching heel and arch pain. Some patients experience no pain, but others may experience severe pain. Symptoms may increase during long periods of standing, resulting in fatigue. Symptoms may change over time as the condition worsens. The pain may move to the foot's outer side, and some patients may develop arthritis in the ankle and foot.
There are four stages of adult-acquired flatfoot deformity (AAFD). The severity of the deformity determines your stage. For example, Stage I means there is a flatfoot position but without deformity. Pain and swelling from tendinitis is common in this stage. Stage II there is a change in the foot alignment. This means a deformity is starting to develop. The physician can still move the bones back into place manually (passively). Stage III adult-acquired flatfoot deformity (AAFD) tells us there is a fixed deformity. This means the ankle is stiff or rigid and doesn???t move beyond a neutral (midline) position. Stage IV is characterized by deformity in the foot and the ankle. The deformity may be flexible or fixed. The joints often show signs of degenerative joint disease (arthritis).
Non surgical Treatment
Medical or nonoperative therapy for posterior tibial tendon dysfunction involves rest, immobilization, nonsteroidal anti-inflammatory medication, physical therapy, orthotics, and bracing. This treatment is especially attractive for patients who are elderly, who place low demands on the tendon, and who may have underlying medical problems that preclude operative intervention. During stage 1 posterior tibial tendon dysfunction, pain, rather than deformity, predominates. Cast immobilization is indicated for acute tenosynovitis of the posterior tibial tendon or for patients whose main presenting feature is chronic pain along the tendon sheath. A well-molded short leg walking cast or removable cast boot should be used for 6-8 weeks. Weight bearing is permitted if the patient is able to ambulate without pain. If improvement is noted, the patient then may be placed in custom full-length semirigid orthotics. The patient may then be referred to physical therapy for stretching of the Achilles tendon and strengthening of the posterior tibial tendon. Steroid injection into the posterior tibial tendon sheath is not recommended due to the possibility of causing a tendon rupture. In stage 2 dysfunction, a painful flexible deformity develops, and more control of hindfoot motion is required. In these cases, a rigid University of California at Berkley (UCBL) orthosis or short articulated ankle-foot orthosis (AFO) is indicated. Once a rigid flatfoot deformity develops, as in stage 3 or 4, bracing is extended above the ankle with a molded AFO, double upright brace, or patellar-tendon-bearing brace. The goals of this treatment are to accommodate the deformity, prevent or slow further collapse, and improve walking ability by transferring load to the proximal leg away from the collapsed medial midfoot and heel.
If conservative treatment fails to provide relief of pain and disability then surgery is considered. Numerous factors determine whether a patient is a surgical candidate. They include age, obesity, diabetes, vascular status, and the ability to be compliant with post-operative care. Surgery usually requires a prolonged period of nonweightbearing immobilization. Total recovery ranges from 3 months to one year. Clinical, x-ray, and MRI examination are all used to select the appropriate surgical procedure.