Originally known as posterior tibial tendon dysfunction or insufficiency, adult-acquired
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.
Causes of an adult acquired flatfoot may include Neuropathic foot (Charcot foot) secondary to Diabetes mellitus, Leprosy, Profound peripheral neuritis of any cause. Degenerative changes in the ankle,
talonavicular or tarsometatarsal joints, or both, secondary to Inflammatory arthropathy, Osteoarthropathy, Fractures, Acquired flatfoot resulting from loss of the supporting structures of the medial
longitudinal arch. Dysfunction of the tibialis posterior tendon Tear of the spring (calcaneoanvicular) ligament (rare). Tibialis anterior rupture (rare). Painful flatfoot can have other causes, such
as tarsal coalition, but as such a patient will not present with a change in the shape of the foot these are not included here.
The first stage represents inflammation and symptoms originating from an irritated posterior tibial tendon, which is still functional. Stage two is characterized by a change in the alignment of the
foot noted on observation while standing (see above photos). The deformity is supple meaning the foot is freely movable and a ?normal? position can be restored by the examiner. Stage two is also
associated with the inability to perform a single-leg heel rise. The third stage is dysfunction of the posterior tibial tendon is a flatfoot deformity that becomes stiff because of arthritis.
Prolonged deformity causes irritation to the involved joints resulting in arthritis. The fourth phase is a flatfoot deformity either supple (stage two) or stiff (stage 3) with involvement of the
ankle joint. This occurs when the deltoid ligament, the major supporting structure on the inside of the ankle, fails to provide support. The ankle becomes unstable and will demonstrate a tilted
appearance on X-ray. Failure of the deltoid ligament results from an inward displacement of the weight bearing forces. When prolonged, this change can lead to ankle arthritis. The vast majority of
patients with acquired adult flatfoot deformity are stage 2 by the time they seek treatment from a physician.
Diagnostic testing is often used to diagnose the condition and help determine the stage of the disease. The most common test done in the office setting are weightbearing X-rays of the foot and ankle.
These assess joint alignment and osteoarthritis. If tendon tearing or rupture is suspected, the gold standard test would be MRI. The MRI is used to check the tendon, surrounding ligament structures
and the midfoot and hindfoot joints. An MRI is essential if surgery is being considered.
Non surgical Treatment
Treatment depends very much upon a patient?s symptoms, functional goals, degree and specifics of deformity, and the presence of arthritis. Some patients get better without surgery. Rest and
immobilization, orthotics, braces and physical therapy all may be appropriate. With early-stage disease that involves pain along the tendon, immobilization with a boot for a period of time can
relieve stress on the tendon and reduce the inflammation and pain. Once these symptoms have resolved, patients are often transitioned into an orthotic that supports the inside aspect of the hindfoot.
For patients with more significant deformity, a larger ankle brace may be necessary.
For more chronic flatfoot pain, surgical intervention may be the best option. Barring other serious medical ailments, surgery is a good alternative for patients with a serious problem. There are two
surgical options depending on a person?s physical condition, age and lifestyle. The first type of surgery involves repair of the PTT by transferring of a nearby tendon to help re-establish an arch
and straighten out the foot. After this surgery, patients wear a non-weight bearing support boot for four to six weeks. The other surgery involves fusing of two or three bones in the hind foot below
the ankle. While providing significant pain relief, this option does take away some hind foot side-to-side motion. Following surgery, patients are in a cast for three months. Surgery is an effective
treatment to address adult-acquired flatfoot, but it can sometimes be avoided if foot issues are resolved early. That is why it is so important to seek help right away if you are feeling ankle pain.
But perhaps the best way to keep from becoming flatfooted is to avoid the risk factors altogether. This means keeping your blood pressure, weight and diabetes in check.