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.
As the name suggests, adult-acquired flatfoot occurs once musculoskeletal maturity is reached, and it can present for a number of reasons, though one stands out among the others. While fractures, dislocations, tendon lacerations, and other such traumatic events do contribute to adult-acquired flatfoot as a significant lower extremity disorder, as mentioned above, damage to the posterior tibial tendon is most often at the heart of adult-acquired flatfoot. One study further elaborates on the matter by concluding that ?60% of patients [presenting with posterior tibial tendon damage and adult-acquired flatfoot] were obese or had diabetes mellitus, hypertension, previous surgery or trauma to the medial foot, or treatment with steroids?.
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.
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
The adult acquired flatfoot is best treated early. There is no recommended home treatment other than the general avoidance of prolonged weightbearing in non-supportive footwear until the patient can be seen in the office of the foot and ankle specialist. In Stage I, the inflammation and tendon injury will respond to rest, protected ambulation in a cast, as well as anti-inflammatory therapy. Follow-up treatment with custom-molded foot orthoses and properly designed athletic or orthopedic footwear are critical to maintain stability of the foot and ankle after initial symptoms have been calmed. Once the tendon has been stretched, the foot will become deformed and visibly rolled into a pronated position at the ankle. Non-surgical treatment has a significantly lower chance of success. Total immobilization in a cast or Camwalker may calm down symptoms and arrest progression of the deformity in a smaller percentage of patients. Usually, long-term use of a brace known as an ankle foot orthosis is required to stop progression of the deformity without surgery. A new ankle foot orthosis known as the Richie Brace, offered by PAL Health Systems, has proven to show significant success in treating Stage II posterior tibial dysfunction and the adult acquired flatfoot. This is a sport-style brace connected to a custom corrected foot orthotic device that fits well into most forms of lace-up footwear, including athletic shoes. The brace is light weight and far more cosmetically appealing than the traditional ankle foot orthosis previously prescribed.
Surgery should only be done if the pain does not get better after a few months of conservative treatment. The type of surgery depends on the stage of the PTTD disease. It it also dictated by where tendonitis is located and how much the tendon is damaged. Surgical reconstruction can be extremely complex. Some of the common surgeries include. Tenosynovectomy, removing the inflamed tendon sheath around the PTT. Tendon Transfer, to augment the function of the diseased posterior tibial tendon with a neighbouring tendon. Calcaneo-osteotomy, sometimes the heel bone needs to be corrected to get a better heel bone alignment. Fusion of the Joints, if osteoarthritis of the foot has set in, fusion of the joints may be necessary.