Adult acquired flatfoot
is one of the most common problems affecting the foot and ankle.
Treatment ranges from nonsurgical methods, such as orthotics and braces to surgery. Your doctor will create a treatment plan for you based on what is causing your AAFD.
There are numerous causes of acquired adult flatfoot, including fracture or dislocation, tendon laceration, tarsal coalition, arthritis, neuroarthropathy, neurologic weakness, and iatrogenic causes.
The most common cause of acquired adult flatfoot is posterior tibial tendon dysfunction.
Patients will usually describe their initial symptoms as "ankle pain", as the PT Tendon becomes painful around the inside of the ankle joint. The pain will become more intense as the foot flattens
out, due to the continued stretching and tearing of the PT Tendon. As the arches continue to fall, and pronation increases, the heel bone (Calcaneus) tilts into a position where it pinches against
the ankle bone (Fibula), causing pain on both the inside and outside of the ankle. As the foot spends increased time in a flattened, or deformed position, Arthritis can begin to affect the joints of
the foot, causing additional pain.
The adult acquired flatfoot, secondary to posterior tibial tendon dysfunction, is diagnosed in a number of ways with no single test proven to be totally reliable. The most accurate diagnosis is made
by a skilled clinician utilizing observation and hands on evaluation of the foot and ankle. Observation of the foot in a walking examination is most reliable. The affected foot appears more pronated
and deformed compared to the unaffected foot. Muscle testing will show a strength deficit. An easy test to perform in the office is the single foot raise. A patient is asked to step with full body
weight on the symptomatic foot, keeping the unaffected foot off the ground. The patient is then instructed to "raise up on the tip toes" of the affected foot. If the posterior tibial tendon has been
attenuated or ruptured, the patient will be unable to lift the heel off the floor and rise onto the toes. In less severe cases, the patient will be able to rise on the toes, but the heel will not be
noted to invert as it normally does when we rise onto the toes. X-rays can be helpful but are not diagnostic of the adult acquired flatfoot. Both feet - the symptomatic and asymptomatic - will
demonstrate a flatfoot deformity on x-ray. Careful observation may show a greater severity of deformity on the affected side.
Non surgical Treatment
Footwear has an important role, and patients should be encouraged to wear flat lace-up shoes, or even lace-up boots, which accommodate orthoses. Stage I patients may be able to manage with an off the
shelf orthosis (such as an Orthaheel or Formthotics). They can try a laced canvas ankle brace before moving to a casted orthosis. The various casted, semirigid orthoses support the medial
longitudinal arch of the foot and either hold the heel in a neutral alignment (stage I) or correct the outward bent heel to a neutral alignment (stage II). This approach is meant to serve several
functions: to alleviate stress on the tibialis posterior; to make gait more efficient by holding the hindfoot fixed; and thirdly, to prevent progression of deformity. Devices available to do this are
the orthosis of the University of California Biomechanics Laboratory, an ankle foot orthosis, or a removable boot. When this approach has been used, two thirds of patients have good to excellent
Although non-surgical treatments can successfully manage the symptoms, they do not correct the underlying problem. It can require a life-long commitment to wearing the brace during periods of
increased pain or activity demands. This will lead a majority of patients to choose surgical correction of the deformity, through Reconstructive Surgery. All of the considerations that were extremely
important during the evaluation stage become even more important when creating a surgical plan. Generally, a combination of procedures are utilized in the same setting, to allow full correction of
the deformity. Many times, this can be performed as a same-day surgery, without need for an overnight hospital stay. However, one or two day hospital admissions can be utilized to help manage the
post-operative pain. Although the recovery process can require a significant investment of time, the subsequent decades of improved function and activity level, as well as decreased pain, leads to a
substantial return on your investment.