Overview Have you noticed the arch in your foot collapse over a fairly short period of time as an adult? Or Do you suffer from pain on the inside and sole of your arch? If it does, then you may be suffering from a condition known as adult acquired flat foot. As one of the main support structures of the foot?s arch, the tibilais posterior tendon, along with other muscles, tendons and ligaments, play a very important role in its mechanical function. Causes Adult flatfoot typically occurs very gradually. If often develops in an obese person who already has somewhat flat feet. As the person ages, the tendons and ligaments that support the foot begin to lose their strength and elasticity. Symptoms Symptoms are minor and may go unnoticed, Pain dominates, rather than deformity. Minor swelling may be visible along the course of the tendon. Pain and swelling along the course of the tendon. Visible decrease in arch height. Aduction of the forefoot on rearfoot. Subluxed tali and navicular joints. Deformation at this point is still flexible. Considerable deformity and weakness. Significant pain. Arthritic changes in the tarsal joints. Deformation at this point is rigid. Diagnosis The diagnosis of tibialis posterior dysfunction is essentially clinical. However, plain radiographs of the foot and ankle are useful for assessing the degree of deformity and to confirm the presence or absence of degenerative changes in the subtalar and ankle articulations. The radiographs are also useful to exclude other causes of an acquired flatfoot deformity. The most useful radiographs are bilateral anteroposterior and lateral radiographs of the foot and a mortise (true anteroposterior) view of the ankle. All radiographs should be done with the patient standing. In most cases we see no role for magnetic resonance imaging or ultrasonography, as the diagnosis can be made clinically. Non surgical Treatment The following is a summary of conservative treatments for acquired flatfoot. Stage 1, NSAIDs and short-leg walking cast or walker boot for 6-8 weeks; full-length semirigid custom molded orthosis, physical therapy. Stage 2, UCBL orthosis or short articulated ankle orthosis. Stage 3, Molded AFO, double-upright brace, or patellar tendon-bearing brace. Stage 4, Molded AFO, double-upright brace, or patellar tendon-bearing brace. Surgical Treatment In cases of PTTD that have progressed substantially or have failed to improve with non-surgical treatment, surgery may be required. For some advanced cases, surgery may be the only option. Your foot and ankle surgeon will determine the best approach for you.