Have you noticed that the medial arch of your foot is becoming flatter when you walk? You may be developing adult acquired flat foot. This condition is typically caused by a problem with a tendon on the medial side of your foot called the Posterior Tibial Tendon that is not functioning well. You may experience pain in the inner side of your foot when you walk. The affected foot appears to roll outwards (the sole of the foot is trying to face outwards) when you walk. This is called over-pronation of the foot. The back of your heel may start to point outwards (heel valgus). Over time you may lose the ability to tip toe on that foot as the posterior tibial tendon stretches out and it may eventually tear.
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.
Observation by a skilled foot clinician and a hands-on evaluation of the foot and ankle is the most accurate diagnostic technique. Your Dallas foot doctor may have you do a walking examination (the most reliable way to check for the deformity). During walking, the affected foot appears more pronated and deformed. Your podiatrist may do muscle testing to look for strength deficiencies. During a single foot raise test, the foot doctor will ask you to rise up on the tip of your toes while keeping your unaffected foot off the ground. If your posterior tendon has been attenuated or ruptured, you will be unable to lift your heel off the floor. In less severe cases, it is possible to rise onto your toes, but your heel will not invert normally. X-rays are not always helpful as a diagnostic tool for Adult Flatfoot because both feet will generally demonstrate a deformity. MRI (magnetic resonance imaging) may show tendon injury and inflammation, but can?t always be relied on for a complete diagnosis. In most cases, a MRI is not necessary to diagnose a posterior tibial tendon injury. An ultrasound may also be used to confirm the deformity, but is usually not required for an initial diagnosis.
Non surgical Treatment
Conservative treatment is indicated for nearly all patients initially before surgical management is considered. The key factors in determining appropriate treatment are whether acute inflammation and whether the foot deformity is flexible or fixed. However, the ultimate treatment is often determined by the patients, most of whom are women aged 40 or older. Compliance can be a problem, especially in stages I and II. It helps to emphasise to the patients that tibialis posterior dysfunction is a progressive and chronic condition and that several fittings and a trial of several different orthoses or treatments are often needed before a tolerable treatment is found.
Surgical treatment should be considered when all other conservative treatment has failed. Surgery options for flatfoot reconstruction depend on the severity of the flatfoot. Surgery for a flexible flatfoot deformity (flatfoot without arthritis to the foot joints) involves advancing the posterior tibial tendon under the arch to provide more support and decrease elongation of the tendon as well as addressing the hindfoot eversion with a osteotomy to the calcaneus (surgical cut in the heel bone). Additionally, the Achilles tendon may need to be lengthened because of the compensatory contracture of the Achilles tendon with flatfoot deformity. Flatfoot deformity with arthritic changes to the foot is considered a rigid flatfoot. Correction of a rigid flatfoot deformity usually involves surgical fusion of the hindfoot joints. This is a reconstructive procedure which allows the surgeon to re-position the foot into a normal position. Although the procedure should be considered for advanced PTTD, it has many complications and should be discussed at length with your doctor.