Overview Over 60 Million Americans suffer from Adult Acquired Flatfoot (AAF), otherwise known as Posterior Tibial Tendon Dysfunction or PTTD. This condition generally occurs in adults from 40-65 years of age, and it usually only occurs in one foot, not both. The Posterior Tibial (PT) Tendon courses along the inside part of the ankle and underneath the arch of the foot. It is the major supporting structure for the arch. Over time, the tendon becomes diseased, from overuse, and starts to lose it's strength. As a result, the arch begins to collapse, placing further strain on the PT Tendon, leading to further decrease in tendon strength, which causes further collapse of the arch. This is described as a progressive deformity because it will generally get worse over time. Causes Overuse of the posterior tibial tendon is often the cause of PTTD. In fact, the symptoms usually occur after activities that involve the tendon, such as running, walking, hiking, or climbing stairs. Symptoms PTTD begins with a gradual stretching and loss of strength of the posterior tibial tendon which is the most important tendon supporting the arch of the human foot. Left untreated, this tendon will continue to lengthen and eventually rupture, leading to a progressive visible collapse of the arch of the foot. In the early stages, patients with PTTD will notice a pain and swelling along the inner ankle and arch. Many times, they are diagnosed with ?tendonitis? of the inner ankle. If the foot and ankle are not properly supported during this early phase, the posterior tibial tendon can rupture and devastating consequences will occur to the foot and ankle structure. The progressive adult acquired flatfoot deformity will cause the heel to roll inward in a ?valgus? or pronated direction while the forefoot will rotate outward causing a ?duckfooted? walking pattern. Eventually, significant arthritis can occur in the joints of the foot, the ankle and even the knee. Early diagnosis and treatment is critical so if you have noticed that one, or both, of your feet has become flatter in recent times come in and have it checked out. Diagnosis Looking at the patient when they stand will usually demonstrate a flatfoot deformity (marked flattening of the medial longitudinal arch). The front part of the foot (forefoot) is often splayed out to the side. This leads to the presence of a ?too many toes? sign. This sign is present when the toes can be seen from directly behind the patient. The gait is often somewhat flatfooted as the patient has the dysfunctional posterior tibial tendon can no longer stabilize the arch of the foot. The physician?s touch will often demonstrate tenderness and sometimes swelling over the inside of the ankle just below the bony prominence (the medial malleolus). There may also be pain in the outside aspect of the ankle. This pain originates from impingement or compression of two tendons between the outside ankle bone (fibula) and the heel bone (calcaneus) when the patient is standing. Non surgical Treatment The adult acquired flatfoot is best treated early. There is no recommended home treatment other than the general avoidance of prolonged weightbearing in non-supportive footwear until the patient can be seen in the office of the foot and ankle specialist. In Stage I, the inflammation and tendon injury will respond to rest, protected ambulation in a cast, as well as anti-inflammatory therapy. Follow-up treatment with custom-molded foot orthoses and properly designed athletic or orthopedic footwear are critical to maintain stability of the foot and ankle after initial symptoms have been calmed. Once the tendon has been stretched, the foot will become deformed and visibly rolled into a pronated position at the ankle. Non-surgical treatment has a significantly lower chance of success. Total immobilization in a cast or Camwalker may calm down symptoms and arrest progression of the deformity in a smaller percentage of patients. Usually, long-term use of a brace known as an ankle foot orthosis is required to stop progression of the deformity without surgery. A new ankle foot orthosis known as the Richie Brace, offered by PAL Health Systems, has proven to show significant success in treating Stage II posterior tibial dysfunction and the adult acquired flatfoot. This is a sport-style brace connected to a custom corrected foot orthotic device that fits well into most forms of lace-up footwear, including athletic shoes. The brace is light weight and far more cosmetically appealing than the traditional ankle foot orthosis previously prescribed. Surgical Treatment Many operations are available for the treatment of dysfunction of the posterior tibial tendon after a thorough program of non-operative treatment has failed. The type of operation that is selected is determined by the age, weight, and level of activity of the patient as well as the extent of the deformity. The clinical stages outlined previously are a useful guide to operative care (Table I). In general, the clinician should perform the least invasive procedure that will decrease pain and improve function. One should consider the effects of each procedure, particularly those of arthrodesis, on the function of the rest of the foot and ankle.