Over 60 Million Americans suffer from Adult Acquired Flatfoot (AAF), otherwise known as Posterior Tibial Tendon Dysfunction or PTTD. This condition generally occurs in adults from 40-65 years of age, and it usually only occurs in one foot, not both. The Posterior Tibial (PT) Tendon courses along the inside part of the ankle and underneath the arch of the foot. It is the major supporting structure for the arch. Over time, the tendon becomes diseased, from overuse, and starts to lose it’s strength. As a result, the arch begins to collapse, placing further strain on the PT Tendon, leading to further decrease in tendon strength, which causes further collapse of the arch. This is described as a progressive deformity because it will generally get worse over time.
A person with flat feet has greater load placed on the posterior tibial tendon which is the main tendon unit supporting up the arch of the foot. Throughout life, aging leads to decreased strength of muscles, tendons and ligaments. The blood supply diminishes to tendons with aging as arteries narrow. Heavier, obese patients have more weight on the arch and have greater narrowing of arteries due to atherosclerosis. In some people, the posterior tibial tendon finally gives out or tears. This is not a sudden event in most cases. Rather, it is a slow, gradual stretching followed by inflammation and degeneration of the tendon. Once the posterior tibial tendon stretches, the ligaments of the arch stretch and tear. The bones of the arch then move out of position with body weight pressing down from above. The foot rotates inward at the ankle in a movement called pronation. The arch appears collapsed, and the heel bone is tilted to the inside. The deformity can progress until the foot literally dislocates outward from under the ankle joint.
Patients will usually describe their initial symptoms as “ankle pain”, as the PT Tendon becomes painful around the inside of the ankle joint. The pain will become more intense as the foot flattens out, due to the continued stretching and tearing of the PT Tendon. As the arches continue to fall, and pronation increases, the heel bone (Calcaneus) tilts into a position where it pinches against the ankle bone (Fibula), causing pain on both the inside and outside of the ankle. As the foot spends increased time in a flattened, or deformed position, Arthritis can begin to affect the joints of the foot, causing additional pain.
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
Get treated early. There is no recommended home treatment. While in stage one of the deformity, rest, a cast, and anti-inflammatory therapy can help you find relief. This treatment is followed by creating custom-molded foot orthoses and orthopedic footwear. These customized items are critical in maintaining the stability of the foot and ankle. Once the tendon has stretched and deformity is visible, the chances of success for non-surgical treatment are significantly lower. In a small percentage of patients, total immobilization may arrest the progression of the deformity. A long-term brace known as an ankle foot orthosis is required to keep the deformity from progressing. The Richie Brace, a type of ankle foot orthosis, shows significant success as a treatment for stage two posterior tibial dysfunction. It is a sport-style brace connected to a custom corrected foot orthodic that fits into most lace-up footwear (including athletic shoes). It is also light weight and more cosmetically appealing than traditionally prescribed ankle foot orthosis. The Arizona Brace, California Brace or Gauntlet Brace may also be recommended depending on your needs.
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.