A variety of foot problems can lead to adult acquired flatfoot
deformity (AAFD), a condition that
results in a fallen arch with the foot pointed outward. Most people - no matter what the cause of their flatfoot - can be helped with orthotics and braces. In patients who have tried orthotics and
braces without any relief, surgery can be a very effective way to help with the pain and deformity. This article provides a brief overview of the problems that can result in AAFD. Further details
regarding the most common conditions that cause an acquired flatfoot and their treatment options are provided in separate articles. Links to those articles are provided.
There are numerous causes of acquired Adult Flatfoot, including, trauma, fracture, dislocation, tendon rupture/partial rupture or inflammation of the tendons, tarsal coalition, arthritis,
neuroarthropathy and neurologic weakness. The most common cause of acquired Adult Flatfoot is due to overuse of a tendon on the inside of the ankle called the posterior tibial tendon. This is classed
as - posterior tibial tendon dysfunction. What are the causes of Adult Acquired flat foot? Trauma, Fracture or dislocation. Tendon rupture, partial tear or inflammation. Tarsal Coalition. Arthritis.
Neuroarthropathy. Neurological weakness.
Posterior tibial tendon insufficiency is divided into stages by most foot and ankle specialists. In stage I, there is pain along the posterior tibial tendon without deformity or collapse of the arch.
The patient has the somewhat flat or normal-appearing foot they have always had. In stage II, deformity from the condition has started to occur, resulting in some collapse of the arch, which may or
may not be noticeable. The patient may feel it as a weakness in the arch. Many patients initially present in stage II, as the ligament failure can occur at the same time as the tendon failure and
therefore deformity can already be occurring as the tendon is becoming symptomatic. In stage III, the deformity has progressed to the extent where the foot becomes fixed (rigid) in its deformed
position. Finally, in stage IV, deformity occurs at the ankle in addition to the deformity in the foot.
Perform a structural assessment of the foot and ankle. Check the ankle for alignment and position. When it comes to patients with severe PTTD, the deltoid has failed, causing an instability of the
ankle and possible valgus of the ankle. This is a rare and difficult problem to address. However, if one misses it, it can lead to dire consequences and potential surgical failure. Check the heel
alignment and position of the heel both loaded and during varus/valgus stress. Compare range of motion of the heel to the normal contralateral limb. Check alignment of the midtarsal joint for
collapse and lateral deviation. Noting the level of lateral deviation in comparison to the contralateral limb is critical for surgical planning. Check midfoot alignment of the naviculocuneiform
joints and metatarsocuneiform joints both for sag and hypermobility.
Non surgical Treatment
The adult acquired flatfoot is best treated early. There is no recommended home treatment other than the general avoidance of prolonged weightbearing in non-supportive footwear until the patient can
be seen in the office of the foot and ankle specialist. In Stage I, the inflammation and tendon injury will respond to rest, protected ambulation in a cast, as well as anti-inflammatory therapy.
Follow-up treatment with custom-molded foot orthoses and properly designed athletic or orthopedic footwear are critical to maintain stability of the foot and ankle after initial symptoms have been
calmed. Once the tendon has been stretched, the foot will become deformed and visibly rolled into a pronated position at the ankle. Non-surgical treatment has a significantly lower chance of success.
Total immobilization in a cast or Camwalker may calm down symptoms and arrest progression of the deformity in a smaller percentage of patients. Usually, long-term use of a brace known as an ankle
foot orthosis is required to stop progression of the deformity without surgery. A new ankle foot orthosis known as the Richie Brace, offered by PAL Health Systems, has proven to show significant
success in treating Stage II posterior tibial dysfunction and the adult acquired flatfoot. This is a sport-style brace connected to a custom corrected foot orthotic device that fits well into most
forms of lace-up footwear, including athletic shoes. The brace is light weight and far more cosmetically appealing than the traditional ankle foot orthosis previously prescribed.
In cases where cast immobilization, orthoses and shoe therapy have failed, surgery is the next alternative. The goal of surgery and non-surgical treatment is to eliminate pain, stop progression of
the deformity and improve mobility of the patient. Opinions vary as to the best surgical treatment for adult acquired flatfoot. Procedures commonly used to correct the condition include tendon
debridement, tendon transfers, osteotomies (cutting and repositioning of bone) and joint fusions. (See surgical correction of adult acquired flatfoot). Patients with adult acquired flatfoot are
advised to discuss thoroughly the benefits vs. risks of all surgical options. Most procedures have long-term recovery mandating that the correct procedure be utilized to give the best long-term
benefit. Most flatfoot surgical procedures require six to twelve weeks of cast immobilization. Joint fusion procedures require eight weeks of non-weightbearing on the operated foot - meaning you will
be on crutches for two months. The bottom line is, Make sure all of your non-surgical options have been covered before considering surgery. Your primary goals with any treatment are to eliminate pain
and improve mobility. In many cases, with the properly designed foot orthosis or ankle brace, these goals can be achieved without surgical intervention.