Originally known as posterior tibial tendon dysfunction or insufficiency, adult-acquired flatfoot
deformity encompasses a wide range of
deformities. These deformities vary in location, severity, and rate of progression. Establishing a diagnosis as early as possible is one of the most important factors in treatment. Prompt early,
aggressive nonsurgical management is important. A patient in whom such treatment fails should strongly consider surgical correction to avoid worsening of the deformity. In all four stages of
deformity, the goal of surgery is to achieve proper alignment and maintain as much flexibility as possible in the foot and ankle complex. However, controversy remains as to how to manage flexible
deformities, especially those that are severe.
Adult flatfoot typically occurs very gradually. If often develops in an obese person who already has somewhat flat feet. As the person ages, the tendons and ligaments that support the foot begin to
lose their strength and elasticity.
Your feet tire easily or become painful with prolonged standing. It's difficult to move your heel or midfoot around, or to stand on your toes. Your foot aches, particularly in the heel or arch area,
with swelling along the inner side. Pain in your feet reduces your ability to participate in sports. You've been diagnosed with rheumatoid arthritis; about half of all people with rheumatoid
arthritis will develop a progressive flatfoot deformity.
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 therapy for posterior tibial tendon dysfunction has been shown to yield 67% good-to-excellent results in 49 patients with stage 2 and 3 deformities. A rigid UCBL orthosis with a medial
forefoot post was used in nonobese patients with flexible heel deformities correctible to neutral and less than 10? of forefoot varus. A molded ankle foot orthosis was used in obese patients with
fixed deformity and forefoot varus greater than 10?. Average length of orthotic use was 15 months. Four patients ultimately elected to have surgery. The authors concluded that orthotic management is
successful in older low-demand patients and that surgical treatment can be reserved for those patients who fail nonoperative treatment.
If cast immobilization fails, surgery is the next alternative. Treatment goals include eliminating pain, halting deformity progression and improving mobility. Subtalar Arthroereisis, 15 minute
outpatient procedure, may correct flexible flatfoot deformity (hyperpronation). The procedure involves placing an implant under the ankle joint (sinus tarsi) to prevent abnormal motion. Very little
recovery time is required and it is completely reversible if necessary. Ask your Dallas foot doctor for more information about this exciting treatment possibility.