What Can Cause Posterior Tibial Tendon Dysfunction (PTTD) ?
Overview
PTTD is a condition of degeneration and dysfunction in the tendon complex that helps control the medial arch of your foot. Essentially what happens is the complex is unable to do its job of supporting the arch and supinating the foot, so a progressive flat foot develops (usually called adult acquired flat foot). Initially pain and often swelling develops on the inside of the ankle and it will continue to get progressively worse. There are a number of stages of PTTD (3 Stages) and it needs to be aggressively treated early on otherwise a surgical reconstruction of the arch will invariably be required. PTTD can develop into a very disabling condition if it is not dealt with properly and promptly. As PTTD becomes more advanced, the arch flattens even more and the pain often shifts to the outside of the foot, below the ankle. Arthritis often develops in the foot and In more severe cases, arthritis may also develop in the ankle. 
Causes
The cause of posterior tibial tendon insufficiency is not completely understood. The condition commonly does not start from one acute trauma but is a process of gradual degeneration of the soft tissues supporting the medial (inner) side of the foot. It is most often associated with a foot that started out somewhat flat or pronated (rolled inward). This type of foot places more stress on the medial soft tissue structures, which include the posterior tibial tendon and ligaments on the inner side of the foot. Children nearly fully grown can end up with flat feet, the majority of which are no problem. However, if the deformity is severe enough it can cause significant functional limitations at that age and later on if soft tissue failure occurs. Also, young adults with normally aligned feet can acutely injure their posterior tibial tendon from a trauma and not develop deformity. The degenerative condition in patients beyond their twenties is different from the acute injuries in young patients or adolescent deformities, where progression of deformity is likely to occur.
Symptoms
Symptoms of pain may have developed gradually as result of overuse or they may be traced to one minor injury. Typically, the pain localizes to the inside (medial) aspect of the ankle, under the medial malleolus. However, some patients will also experience pain over the outside (lateral) aspect of the hindfoot because of the displacement of the calcaneus impinging with the lateral malleolus. This usually occurs later in the course of the condition. Patients may walk with a limp or in advanced cases be disabled due to pain. They may also have noticed worsening of their flatfoot deformity.
Diagnosis
It is of great importance to have a full evaluation, by a foot and ankle specialist with expertise in addressing complex flatfoot deformities. No two flat feet are alike; therefore, "Universal" treatment plans do not exist for the Adult Flatfoot. It is important to have a custom treatment plan that is tailored to your specific foot. That starts by first understanding all the intricacies of your foot, through an extensive evaluation. X-rays of the foot and ankle are standard, and MRI may be used to better assess the quality of the PT Tendon.
Non surgical Treatment
Treatment of Adult Acquired Flatfoot Deformity depends on the stage of progression, as mentioned above paragraphs. Below we will outline a variety of different treatment options available. Orthotics or bracing. To give your foot the arch the support it needs, your podiatrist or foot specialist may provide you with over the counter brace or a custom orthotic device that fits your shoe. Casting. In some cases, a cast or boot is worn to stabilize the foot and to give the tendon time to heal. Physiotherapy. Ultrasound treatments and exercises may help rehab the tendon and muscles. Medications. Over-the-counter (NSAIDS) such as ibuprofen can help reduce pain, inflammation and swelling associated with AAFD. Shoe Gear. Your podiatrist may suggest changes with your shoes you are wearing and inserts you need in your shoe to help support your arch. 
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.
