(AAF) is the term used to describe the progressive deformity of the foot and ankle that, in its later stages, results in collapsed and
badly deformed feet. Although the condition has been described and written about since the 1980s, AAF is not a widely used acronym within the O&P community-even though orthotists and pedorthists
easily recognize the signs of the condition because they treat them on an almost daily basis. AAF is caused by a loss of the dynamic and static support structures of the medial longitudinal arch,
resulting in an incrementally worsening planovalgus deformity associated with posterior tibial (PT) tendinitis. Over the past 30 years, researchers have attempted to understand and explain the
gradual yet significant deterioration that can occur in foot structure, which ultimately leads to painful and debilitating conditions-a progression that is currently classified into four stages. What
begins as a predisposition to flatfoot can progress to a collapsed arch, and then to the more severe posterior tibial tendon dysfunction (PTTD). Left untreated, the PT tendon can rupture, and the
patient may then require a rigid AFO or an arthrodesis fixation surgery to stabilize the foot in order to remain capable of walking pain free.
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.
Often, this condition is only present in one foot, but it can affect both. Adult acquired flatfoot symptoms vary, but can swelling of the foot's inner side and aching heel and arch pain. Some
patients experience no pain, but others may experience severe pain. Symptoms may increase during long periods of standing, resulting in fatigue. Symptoms may change over time as the condition
worsens. The pain may move to the foot's outer side, and some patients may develop arthritis in the ankle and foot.
Starting from the knee down, check for any bowing of the tibia. A tibial varum will cause increased medial stress on the foot and ankle. This is essential to consider in surgical planning. Check the
gastrocnemius muscle and Achilles complex via a straight and bent knee check for equinus. If the range of motion improves to at least neutral with bent knee testing of the Achilles complex, one may
consider a gastrocnemius recession. If the Achilles complex is still tight with bent knee testing, an Achilles lengthening may be necessary. Check the posterior tibial muscle along its entire course.
Palpate the muscle and observe the tendon for strength with a plantarflexion and inversion stress test. Check the flexor muscles for strength in order to see if an adequate transfer tendon is
available. Check the anterior tibial tendon for size and strength.
Non surgical Treatment
What are the treatment options? In early stages an orthotic that caters for a medially deviated subtalar joint ac-cess. Examples of these are the RX skive, Medafeet MOSI device. Customised de-vices
with a Kirby skive or MOSI adaptation will provide greater control than a prefabricated device. If the condition develops further a UCBL orthotic or an AFO (ankle foot orthotic) could be necessary
for greater control. Various different forms of surgery are available depending upon the root cause of the issue and severity.
Surgery should only be done if the pain does not get better after a few months of conservative treatment. The type of surgery depends on the stage of the PTTD disease. It it also dictated by where
tendonitis is located and how much the tendon is damaged. Surgical reconstruction can be extremely complex. Some of the common surgeries include. Tenosynovectomy, removing the inflamed tendon sheath
around the PTT. Tendon Transfer, to augment the function of the diseased posterior tibial tendon with a neighbouring tendon. Calcaneo-osteotomy, sometimes the heel bone needs to be corrected to get a
better heel bone alignment. Fusion of the Joints, if osteoarthritis of the foot has set in, fusion of the joints may be necessary.