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.
Causes of an adult acquired flatfoot may include Neuropathic foot (Charcot foot) secondary to Diabetes mellitus, Leprosy, Profound peripheral neuritis of any cause. Degenerative changes in the ankle,
talonavicular or tarsometatarsal joints, or both, secondary to Inflammatory arthropathy, Osteoarthropathy, Fractures, Acquired flatfoot resulting from loss of the supporting structures of the medial
longitudinal arch. Dysfunction of the tibialis posterior tendon Tear of the spring (calcaneoanvicular) ligament (rare). Tibialis anterior rupture (rare). Painful flatfoot can have other causes, such
as tarsal coalition, but as such a patient will not present with a change in the shape of the foot these are not included here.
Not everyone with adult flatfoot has problems with pain. Those who do usually experience it around the ankle or in the heel. The pain is usually worse with activity, like walking or standing for
extended periods. Sometimes, if the condition develops from arthritis in the foot, bony spurs along the top and side of the foot develop and make wearing shoes more painful. Diabetic patients need to
watch for swelling or large lumps in the feet, as they may not notice any pain. They are also at higher risk for developing significant deformities from their flatfoot.
Although you can do the "wet test" at home, a thorough examination by a doctor will be needed to identify why the flatfoot developed. Possible causes include a congenital abnormality, a bone fracture
or dislocation, a torn or stretched tendon, arthritis or neurologic weakness. For example, an inability to rise up on your toes while standing on the affected foot may indicate damage to the
posterior tibial tendon (PTT), which supports the heel and forms the arch. If "too many toes" show on the outside of your foot when the doctor views you from the rear, your shinbone (tibia) may be
sliding off the anklebone (talus), another indicator of damage to the PTT. Be sure to wear your regular shoes to the examination. An irregular wear pattern on the bottom of the shoe is another
indicator of acquired adult flatfoot. Your physician may request X-rays to see how the bones of your feet are aligned. Muscle and tendon strength are tested by asking you to move the foot while the
doctor holds it.
Non surgical Treatment
Although AAF is not reversible without surgery, appropriate treatment should address the patient?s current symptoms, attempt to reduce pain, and allow continued ambulation. In the early stages,
orthotic and pedorthic solutions can address the loss of integrity of the foot?s support structures, potentially inhibiting further destruction.3-5 As a general principle, orthotic devices should
only block or limit painful or destructive motion without reducing or restricting normal motion or muscle function. Consequently, the treatment must match the stage of the deformity.
When conservative care fails to control symptoms and/or deformity, then surgery may be needed. The goal of surgical treatment is to obtain good alignment while keeping the foot and ankle as flexible
as possible. The most common procedures used with this condition include arthrodesis (fusion), osteotomy (cutting out a wedge-shaped piece of bone), and lateral column lengthening. Lateral column
lengthening involves the use of a bone graft at the calcaneocuboid joint. This procedure helps restore the medial longitudinal arch (arch along the inside of the foot). A torn tendon or spring
ligament will be repaired or reconstructed. Other surgical options include tendon shortening or lengthening. Or the surgeon may move one or more tendons. This procedure is called a tendon transfer.
Tendon transfer uses another tendon to help the posterior tibial tendon function more effectively. A tendon transfer is designed to change the force and angle of pull on the bones of the arch. It's
not clear yet from research evidence which surgical procedure works best for this condition. A combination of surgical treatments may be needed. It may depend on your age, type and severity of
deformity and symptoms, and your desired level of daily activity.