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.
The most common cause of acquired adult flatfoot is posterior tibial tendon dysfunction. What causes adult acquired flat foot? Fracture or dislocation. Tendon laceration. Tarsal Coalition. Arthritis. Neuroarthropathy. Neurological weakness.
Patients often experience pain and/or deformity at the ankle or hindfoot. When the posterior tibial tendon does not work properly, a number of changes can occur to the foot and ankle. In the earlier stages, symptoms often include pain and tenderness along the posterior tibial tendon behind the inside of the ankle. As the tendon progressively fails, deformity of the foot and ankle may occur. This deformity can include progressive flattening of the arch, shifting of the heel so that it no longer is aligned underneath the rest of the leg, rotation and deformity of the forefoot, tightening of the heel cord, development of arthritis, and deformity of the ankle joint. At certain stages of this disorder, pain may shift from the inside to the outside aspect of the ankle as the heel shifts outward and structures are pinched laterally.
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
Nonoperative treatment of stage 1 and 2 acquired adult flatfoot deformity can be successful. General components of the treatment include the use of comfort shoes. Activity modification to avoid exacerbating activities. Weight loss if indicated. Specific components of treatment that over time can lead to marked improvement in symptoms include a high repetition, low resistance strengthening program. Appropriate bracing or a medial longitudinal arch support. If the posterior tibial tendon is intact, a series of exercises aimed at strengthening the elongated and dysfunctional tendon complex can be successful. In stage 2 deformities, this is combined with an ankle brace for a period of 2-3 months until the symptoms resolve. At this point, the patient is transitioned to an orthotic insert which may help to support the arch. In patients with stage 1 deformity it may be possible to use an arch support immediately.
In cases of PTTD that have progressed substantially or have failed to improve with non-surgical treatment, surgery may be required. For some advanced cases, surgery may be the only option. Surgical treatment may include repairing the tendon, tendon transfers, realigning the bones of the foot, joint fusions, or both. Dr. Piccarelli will determine the best approach for your specific case. A variety of surgical techniques is available to correct flexible flatfoot. Your case may require one procedure or a combination of procedures. All of these surgical techniques are aimed at relieving the symptoms and improving foot function. Among these procedures are tendon transfers or tendon lengthening procedures, realignment of one or more bones, or insertion of implant devices. Whether you have flexible flatfoot or PTTD, to select the procedure or combination of procedures for your particular case, Dr. Piccarelli will take into consideration the extent of your deformity based on the x-ray findings, your age, your activity level, and other factors. The length of the recovery period will vary, depending on the procedure or procedures performed.