When we have foot pain, it isn?t always easy to pinpoint the source because we can?t visualize the structure of all the bones, muscles, and tendons on the inside. The posterior tibial tendon plays an important supportive role within the structure of the foot. It attaches to your calf muscle and then comes down along the inside of your ankle, connecting to the bones inside your foot at the other side. This tendon?s main function is to hold up your arch and support your foot during each and every movement. Every step, run, walk, or jump is made possible with the support from this crucial tendon. While it is designed to perform such an important role, it is vulnerable to stress and injury. A tear during a traumatic injury or stress from overuse can injure the tissues within the tendon. This kind of injury is referred to as posterior tibial tendon dysfunction (PTTD). A really hard fall during a sports game or exposure to a repetitive motion, such as the impact on feet during soccer, tennis, football or basketball, can cause an injury. Flat foot and flat feet in adults can exacerbate this condition. The tendon can experience small tears and become inflamed. If the inflammation is allowed to continue and worsen over time, it will weaken further and could rupture completely.
Posterior tibial tendon dysfunction is the most common cause of acquired adult flatfoot deformity. There is often no specific event that starts the problem, such as a sudden tendon injury. More commonly, the tendon becomes injured from cumulative wear and tear. Posterior tibial tendon dysfunction occurs more commonly in patients who already have a flat foot for other reasons. As the arch flattens, more stress is placed on the posterior tibial tendon and also on the ligaments on the inside of the foot and ankle. The result is a progressive disorder.
The symptom most often associated with AAF is PTTD, but it is important to see this only as a single step along a broader continuum. The most important function of the PT tendon is to work in synergy with the peroneus longus to stabilize the midtarsal joint (MTJ). When the PT muscle contracts and acts concentrically, it inverts the foot, thereby raising the medial arch. When stretched under tension, acting eccentrically, its function can be seen as a pronation retarder. The integrity of the PT tendon and muscle is crucial to the proper function of the foot, but it is far from the lone actor in maintaining the arch. There is a vital codependence on a host of other muscles and ligaments that when disrupted leads to an almost predictable loss in foot architecture and subsequent pathology.
Although you can do the "wet test" at home, a thorough examination by a doctor will be needed to identify why the flatfoot developed. Possible causes include a congenital abnormality, a bone fracture or dislocation, a torn or stretched tendon, arthritis or neurologic weakness. For example, an inability to rise up on your toes while standing on the affected foot may indicate damage to the posterior tibial tendon (PTT), which supports the heel and forms the arch. If "too many toes" show on the outside of your foot when the doctor views you from the rear, your shinbone (tibia) may be sliding off the anklebone (talus), another indicator of damage to the PTT. Be sure to wear your regular shoes to the examination. An irregular wear pattern on the bottom of the shoe is another indicator of acquired adult flatfoot. Your physician may request X-rays to see how the bones of your feet are aligned. Muscle and tendon strength are tested by asking you to move the foot while the doctor holds it.
Non surgical Treatment
Patients can be treated non-surgically with in-shoe devices and braces to hold their feet in the correct position. This can reduce pain and damage and assist with walking. Physical therapy is also given to improve muscle strength and help prevent injury to the foot. Surgery can be performed if the patient doesn?t find any relief.
Flatfoot reconstruction (osteotomy). This is often recommended for flexible flatfoot condition. Flatfoot reconstruction involves cutting and shifting the heel bone into a more neutral position, transferring the tendon used to flex the lesser toes (all but the big toe) to strengthen the posterior tibial tendon, and lengthening the calf muscle. Fusion (also known as triple arthrodesis). Fusion involves fusing, or making stiff, three joints in the back of the foot the subtalar, talonavicular, and calcaneocuboid joints, to realign the foot and give it a more natural shape. Pins or screws hold the area in place until it heals. Fusion is often recommended for a rigid flatfoot deformity or evidence of arthritis. Both of these surgeries can provide excellent pain relief and correction.