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.
Overuse of the posterior tibial tendon is often the cause of PTTD. In fact, the symptoms usually occur after activities that involve the tendon, such as running, walking, hiking, or climbing
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.
First, both feet should be examined with the patient standing and the entire lower extremity visible. The foot should be inspected from above as well as from behind the patient, as valgus angulation
of the hindfoot is best appreciated when the foot is viewed from behind. Johnson described the so-called more-toes sign: with more advanced deformity and abduction of the forefoot, more of the
lateral toes become visible when the foot is viewed from behind. The single-limb heel-rise test is an excellent determinant of the function of the posterior tibial tendon. The patient is asked to
attempt to rise onto the ball of one foot while the other foot is suspended off the floor. Under normal circumstances, the posterior tibial muscle, which inverts and stabilizes the hindfoot, is
activated as the patient begins to rise onto the forefoot. The gastrocnemius-soleus muscle group then elevates the calcaneus, and the heel-rise is accomplished. With dysfunction of the posterior
tibial tendon, however, inversion of the heel is weak, and either the heel remains in valgus or the patient is unable to rise onto the forefoot. If the patient can do a single-limb heel-rise, the
limb may be stressed further by asking the patient to perform this maneuver repetitively.
Non surgical Treatment
Conservative (nonoperative) care is advised at first. A simple modification to your shoe may be all that???s needed. Sometimes purchasing shoes with a good arch support is sufficient. For other
patients, an off-the-shelf (prefabricated) shoe insert works well. The orthotic is designed specifically to position your foot in good alignment. Like the shoe insert, the orthotic fits inside the
shoe. These work well for mild deformity or symptoms. Over-the-counter pain relievers or antiinflammatory drugs such as ibuprofen may be helpful. If symptoms are very severe, a removable boot or cast
may be used to rest, support, and stabilize the foot and ankle while still allowing function. Patients with longer duration of symptoms or greater deformity may need a customized brace. The brace
provides support and limits ankle motion. After several months, the brace is replaced with a foot orthotic. A physical therapy program of exercise to stretch and strengthen the foot and leg muscles
is important. The therapist will also show you how to improve motor control and proprioception (joint sense of position). These added features help prevent and reduce injuries.
A new type of surgery has been developed in which surgeons can re-construct the flat foot deformity and also the deltoid ligament using a tendon called the peroneus longus. A person is able to
function fully without use of the peroneus longus but they can also be taken from deceased donors if needed. The new surgery was performed on four men and one woman. An improved alignment of the
ankle was still evident nine years later, and all had good mobility 8 to 10 years after the surgery. None had developed arthritis.