Abstract
Posterior tibial tendon dysfunction (PTTD) is an important cause of acquired pes planus that frequently observed in adults. Factors that play a role in the development of PTTD such as age-related tendon degeneration, inflammatory arthritis, hypertension, diabetes mellitus, obesity, peritendinous injections and more rarely acute traumatic rupture of the tendon. PTT is the primary dynamic stabilizer of medial arch of the foot. Plantar flexion and inversion of the foot occurs with contraction of tibialis posterior tendon, and arch of the foot becomes elaveted while midtarsal joints are locked and midfoot-hindfoot sets as rigid. Thus, during the walk gastrocnemius muscle works more efficiently. If the PTT does not work in the order, other foot ligaments and joint capsule would be increasingly weak and than pes planus occurs. We present a 10-yearold female patient diagnosed as PTTD and conservative treatment with review of the current literature.