Becoming flatfooted can be a real health issue for people. The advice from healthcare experts is to pay attention to foot pain, and when it happens, to seek help right away. In the last 20 years, adult-acquired flatfoot has become a more commonly recognized health issue. The cause is a dysfunction of the ankle tendon that attaches to the bones on the inside of your foot. The function of this posterior tibial tendon (PTT) is to maintain the foot arch and provide strength during push-off when you walk. When the PTT is not functioning correctly, you tend to lose your arch, or become more flatfooted. This problem occurs about three times more often in women than in men, especially after the age of 40. Initially, PTT dysfunction is associated with pain on the inside of the ankle, swelling and sometimes a limp. If left unchecked, the arch appears to collapse and the pain on the inside of the ankle worsens. Eventually, if left unchecked, patients will begin to feel pain on the outside of the ankle, too.
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.
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
Initial treatment is based on the degree of deformity and flexibility at initial presentation. Conservative treatment includes orthotics or ankle foot orthoses (AFO) to support the posterior tibial tendon (PT) and the longitudinal arch, anti-inflammatories to help reduce pain and inflammation, activity modification which may include immobilization of the foot and physical therapy to help strengthen and rehabilitate the tendon.
Surgical correction is dependent on the severity of symptoms and the stage of deformity. The goals of surgery are to create a more functional and stable foot. There are multiple procedures available to the surgeon and it may take several to correct a flatfoot deformity. Usually surgical treatment begins with removal of inflammatory tissue and repair of the posterior tibial tendon. A tendon transfer is performed if the posterior tibial muscle is weak or the tendon is badly damaged. The most commonly used tendon is the flexor digitorum longus tendon. This tendon flexes or moves the lesser toes downward. The flexor digitorum longus tendon is utilized due to its close proximity to the posterior tibial tendon and because there are minimal side effects with its loss. The remainder of the tendon is sutured to the flexor hallucis longus tendon that flexes the big toe so that little function is loss.