Adult acquired flat foot was first described in the late 1960s as something that occurred after trauma, as a result of a tear to the tibial posterior tendon. However, by 1969 two doctors called Kettlekamp and Alexander described cases in which no trauma had taken place. They referred to the condition as "tibial posterior tendon dysfunction" and this became known as the most common type of adult acquired flat foot.
A person with flat feet has greater load placed on the posterior tibial tendon which is the main tendon unit supporting up the arch of the foot. Throughout life, aging leads to decreased strength of muscles, tendons and ligaments. The blood supply diminishes to tendons with aging as arteries narrow. Heavier, obese patients have more weight on the arch and have greater narrowing of arteries due to atherosclerosis. In some people, the posterior tibial tendon finally gives out or tears. This is not a sudden event in most cases. Rather, it is a slow, gradual stretching followed by inflammation and degeneration of the tendon. Once the posterior tibial tendon stretches, the ligaments of the arch stretch and tear. The bones of the arch then move out of position with body weight pressing down from above. The foot rotates inward at the ankle in a movement called pronation. The arch appears collapsed, and the heel bone is tilted to the inside. The deformity can progress until the foot literally dislocates outward from under the ankle joint.
Most people will notice mild to extreme pain in their feet. Below outlines some signs and symptoms of AAFD. Trouble walking or standing for any duration. Pain and swelling on the inside of the ankle. Bump on the bottom of the foot. Ulcer or wound developing on the outer aspects of foot.
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
Treatment depends very much upon a patient?s symptoms, functional goals, degree and specifics of deformity, and the presence of arthritis. Some patients get better without surgery. Rest and immobilization, orthotics, braces and physical therapy all may be appropriate. With early-stage disease that involves pain along the tendon, immobilization with a boot for a period of time can relieve stress on the tendon and reduce the inflammation and pain. Once these symptoms have resolved, patients are often transitioned into an orthotic that supports the inside aspect of the hindfoot. For patients with more significant deformity, a larger ankle brace may be necessary.
Types of surgery your orthopaedist may discuss with you include arthrodesis, or welding (fusing) one or more of the bones in the foot/ankle together. Osteotomy, or cutting and reshaping a bone to correct alignment. Excision, or removing a bone or bone spur. Synovectomy, or cleaning the sheath covering a tendon. Tendon transfer, or using a piece of one tendon to lengthen or replace another. Having flat feet is a serious matter. If you are experiencing foot pain and think it may be related to flat feet, talk to your orthopaedist.