Adult Flatfoot

Flat foot, or pes planus, is a defect of the foot that eliminates the arch. It is most often an inherited condition. Development of this condition in adulthood is sometimes referred to as posterior tibial tendon dysfunction (PTTD) or acquired flatfoot. Although this can occur in anyone, it is seen most frequently in women over 50. The following are risk factors for PTTD:

• Wearing high heels for long periods of time. Over the years, the Achilles tendon in the back of the calf shortens and tightens, limiting the bending motion of the ankle joint. The tendons and ligaments running through the arch then try to compensate. Sometimes they break down and the arch falls.
• Some studies have indicated that the earlier one starts wearing shoes, particularly for long periods of the day, the higher the risk for flat feet later on.
• Other conditions that can lead to PTTD include obesity, diabetes, surgery, injury, rheumatoid arthritis, or use of corticosteroids.

PTTD is often described in 3 stages:

1. Stage I: Inflammation and swelling of the posterior tibial tendon around the ankle.
2. Stage II: Visible deformity comparing one foot to the other, as the symptomatic foot becomes flatter and more deformed. The deformity is movable and correctable in this stage.
3. Stage III: The foot progresses to a rigid, non-movable flat foot deformity that is painful, primarily on the outside of the ankle.

Treatment:

• Conservative treatment for PTTD involves pain relief.
• Insoles or custom-made orthotics to support the foot and prevent progression.
• Surgery may be required to correct the foot posture in severe cases. Procedures include osteotomies or arthrodesis, which typically lengthen the Achilles tendon and adjust tendons in the foot. Since surgery has potential complications, conservative methods should be tried first.