Adult-acquired flatfoot (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.
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.
Symptoms shift around a bit, depending on what stage of PTTD you?re in. For instance, you?re likely to start off with tendonitis, or inflammation of the posterior tibial tendon. This will make the area around the inside of your ankle and possibly into your arch swollen, reddened, warm to the touch, and painful. Inflammation may actually last throughout the stages of PTTD. The ankle will also begin to roll towards the inside of the foot (pronate), your heel may tilt, and you may experience some pain in your leg (e.g. shin splints). As the condition progresses, the toes and foot begin to turn outward, so that when you look at your foot from the back (or have a friend look for you, because-hey-that can be kind of a difficult
maneuver to pull off) more toes than usual will be visible on the outside (i.e. the side with the pinky toe). At this stage, the foot?s still going to be flexible, although it will likely have flattened somewhat due to the lack of support from the posterior tibial tendon. You may also find it difficult to stand on your toes. Finally, you may reach a stage in which your feet are inflexibly flat. At this point, you may experience pain below your ankle on the outside of your foot, and you might even develop arthritis in the ankle.
Your podiatrist is very familiar with tendons that have just about had enough, and will likely be able to diagnose this condition by performing a physical exam of your foot. He or she will probably examine the area visually and by feel, will inquire about your medical history (including past pain or injuries), and may also observe your feet as you walk. You may also be asked to attempt standing on your toes. This may be done by having you lift your ?good? foot (the one without the complaining tendon) off the ground, standing only on your problem foot. (You may be instructed to place your hands against the wall to help with balance.) Then, your podiatrist will ask you to try to go up on your toes on the bad foot. If you have difficulty doing so, it may indicate a problem with your posterior tibial tendon. Some imaging technology may be used to diagnose this condition, although it?s more likely the doctor will rely primarily on a physical exam. However, he or she may order scans such as an MRI or CT scan to look at your foot?s interior, and X-rays might also be helpful in a diagnosis.
Non surgical Treatment
Treatment of Adult Acquired Flatfoot Deformity depends on the stage of progression, as mentioned above paragraphs. Below we will outline a variety of different treatment options available. Orthotics or bracing. To give your foot the arch the support it needs, your podiatrist or foot specialist may provide you with over the counter brace or a custom orthotic device that fits your shoe. Casting. In some cases, a cast or boot is worn to stabilize the foot and to give the tendon time to heal. Physiotherapy. Ultrasound treatments and exercises may help rehab the tendon and muscles. Medications. Over-the-counter (NSAIDS) such as ibuprofen can help reduce pain, inflammation and swelling associated with AAFD. Shoe Gear. Your podiatrist may suggest changes with your shoes you are wearing and inserts you need in your shoe to help support your arch.
Stage two deformities are less responsive to conservative therapies that can be effective in mild deformities. Bone procedures are necessary at this stage in order to recreate the arch and stabilize the foot. These procedures include isolated fusion procedures, bone grafts, and/or the repositioning of bones through cuts called osteotomies. The realigned bones are generally held in place with screws, pins, plates, or staples while the bone heals. A tendon transfer may or may not be utilized depending on the condition of the posterior tibial tendon. Stage three deformities are better treated with surgical correction, in healthy patients. Patients that are unable to tolerate surgery or the prolonged healing period are better served with either arch supports known as orthotics or bracing such as the Richie Brace. Surgical correction at this stage usually requires fusion procedures such as a triple or double arthrodesis. This involves fusing the two or three major bones in the back of the foot together with screws or pins. The most common joints fused together are the subtalar joint, talonavicular joint, and the calcaneocuboid joint. By fusing the bones together the surgeon is able to correct structural deformity and alleviate arthritic pain. Tendon transfer procedures are usually not beneficial at this stage. Stage four deformities are treated similarly but with the addition of fusing the ankle joint.