Most flat feet are not painful, particularly those flat feet seen in children. In the adult acquired flatfoot
occurs because soft tissues (tendons and ligaments) have been torn. The deformity progresses or worsens because once the vital ligaments and posterior tibial tendon are lost, nothing can take their
place to hold up the arch of the foot. The painful, progressive adult acquired flatfoot affects women four times as frequently as men. It occurs in middle to older age people with a mean age of 60
years. Most people who develop the condition already have flat feet. A change occurs in one foot where the arch begins to flatten more than before, with pain and swelling developing on the inside of
the ankle. Why this event occurs in some people (female more than male) and only in one foot remains poorly understood. Contributing factors increasing the risk of adult acquired flatfoot are
diabetes, hypertension, and obesity.
There are numerous causes of acquired adult flatfoot, including fracture or dislocation, tendon laceration, tarsal coalition, arthritis, neuroarthropathy, neurologic weakness, and iatrogenic causes.
The most common cause of acquired adult flatfoot is posterior tibial tendon dysfunction.
Depending on the cause of the flatfoot, a patient may experience one or more of the different symptoms here. Pain along the course of the posterior tibial tendon which lies on the inside of the foot
and ankle. This can be associated with swelling on the inside of the ankle. Pain that is worse with activity. High intensity or impact activities, such as running, can be very difficult. Some
patients can have difficulty walking or even standing for long periods of time. When the foot collapses, the heel bone may shift position and put pressure on the outside ankle bone (fibula). This can
cause pain on the outside of the ankle. Arthritis in the heel also causes this same type of pain. Patients with an old injury or arthritis in the middle of the foot can have painful, bony bumps on
the top and inside of the foot. These make shoewear very difficult. Occasionally, the bony spurs are so large that they pinch the nerves which can result in numbness and tingling on the top of the
foot and into the toes. Diabetics may only notice swelling or a large bump on the bottom of the foot. Because their sensation is affected, people with diabetes may not have any pain. The large bump
can cause skin problems and an ulcer (a sore that does not heal) may develop if proper diabetic shoewear is not used.
Clinicians need to recognize the early stage of this syndrome which includes pain, swelling, tendonitis and disability. The musculoskeletal portion of the clinical exam can help determine the stage
of the disease. It is important to palpate the posterior tibial tendon and test its muscle strength. This is tested by asking patient to plantarflex and invert the foot. Joint range of motion is
should be assessed as well. Stiffness of the joints may indicate longstanding disease causing a rigid deformity. A weightbearing examination should be performed as well. A complete absence of the
medial longitudinal arch is often seen. In later stages the head of the talus bone projects outward to the point of a large "lump" in the arch. Observing the patient's feet from behind shows a
significant valgus rotation of the heel. From behind, the "too many toes" sign may be seen as well. This is when there is abducution of the forefoot in the transverse plane allowing the toes to be
seen from behind. Dysfunction of the posterior tibial tendon can be assessed by asking the patient to stand on his/her toes on the affected foot. If they are unable to, this indicates the disease is
in a more advanced stage with the tendon possibly completely ruptured.
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.
Stage two deformities are less responsive to conservative therapies that can be effective in mild deformities. Bone procedures are necessary at this stage in order to recreate the arch and stabilize
the foot. These procedures include isolated fusion procedures, bone grafts, and/or the repositioning of bones through cuts called osteotomies. The realigned bones are generally held in place with
screws, pins, plates, or staples while the bone heals. A tendon transfer may or may not be utilized depending on the condition of the posterior tibial tendon. Stage three deformities are better
treated with surgical correction, in healthy patients. Patients that are unable to tolerate surgery or the prolonged healing period are better served with either arch supports known as orthotics or
bracing such as the Richie Brace. Surgical correction at this stage usually requires fusion procedures such as a triple or double arthrodesis. This involves fusing the two or three major bones in the
back of the foot together with screws or pins. The most common joints fused together are the subtalar joint, talonavicular joint, and the calcaneocuboid joint. By fusing the bones together the
surgeon is able to correct structural deformity and alleviate arthritic pain. Tendon transfer procedures are usually not beneficial at this stage. Stage four deformities are treated similarly but
with the addition of fusing the ankle joint.