Adult-Acquired Flat Foot Deformity (AAFFD) is most commonly caused by a progressive degeneration of the tendon (tibialis posterior) that supports the arch of the foot. As the tendon ages or is subjected to repetitive trauma, it stretches out over time, the natural arch of the foot becomes less pronounced and the foot gradually flattens out. Although it is uncertain why this occurs, the problem is seen equally among men and women - at an increasing frequency with age. Occasionally, a patient will experience a traumatic form of the condition as a result of a fall from a height or abnormal landing during aerial sports such as gymnastics or basketball.
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.
Pain and swelling behind the inside of your ankle and along your instep. You may be tender behind the inner ankle where the posterior tibial tendon courses and occasionally get burning, shooting, tingling or stabbing pain as a result of inflammation of the nerve inside the tarsal tunnel. Difficulty walking, the inability to walk long distances and a generalised ache while walking even short distances. This may probably become more pronounced at the end of each day. Change in foot shape, sometimes your tendon stretches out, this is due to weakening of the tendon and ligaments. When this occurs, the arch in your foot flattens and a flatfoot deformity occurs, presenting a change in foot shape. Inability to tip-toe, a way of diagnosing Posterior Tibial Tendon Dysfunction is difficulty or inability to ?heel rise? (stand on your toes on one foot). Your tibialis posterior tendon enables you to perform this manoeuvre effectively. You may also experience pain upon attempting to perform a heel rise.
Examination by your foot and ankle specialist can confirm the diagnosis for most patients. An ultrasound exam performed in the office setting can evaluate the status of the posterior tibial tendon, the tendon which is primarily responsible for supporting the arch structure of the foot.
Non surgical Treatment
It is imperative that you seek treatment should you notice any symptoms of a falling arch or PTTD. Due to the progressive nature of this condition, your foot will have a much higher chance of staying strong and healthy with early treatment. When pain first appears, your doctor will evaluate your foot to confirm a flatfoot diagnosis and begin an appropriate treatment plan. This may involve rest, anti-inflammatory medications, shoe modifications, physical therapy, orthotics and a possible boot or brace. When treatment can be applied at the beginning, symptoms can most often be resolved without the need for surgery.
For those patients with PTTD that have severe deformity or have not improved with conservative treatments, surgery may be necessary to return them to daily activity. Surgery for PTTD may include repair of the diseased tendon and possible tendon transfer to a nearby healthy tendon, surgery on the surrounding bones or joints to prevent biomechanical abnormalities that may be a contributing factor or both.