PTTD is a common condition treated by foot and ankle specialists. Although there is a role for surgical treatment of PTTD, conservative care often can prevent or delay surgical intervention. Decreasing inflammation and stabilizing the affected joints associated with the posterior tibial tendon can decrease pain and increase functional levels. With many different modalities available, aggressive nonoperative methods should be considered in the treatment of PTTD, including early immobilization, the use of long-term bracing, physical therapy, and anti-inflammatory medications. If these methods fail, proper evaluation and work-up for surgical intervention should be employed.
Causes of an adult acquired flatfoot may include Neuropathic foot (Charcot foot) secondary to Diabetes mellitus, Leprosy, Profound peripheral neuritis of any cause. Degenerative changes in the ankle, talonavicular or tarsometatarsal joints, or both, secondary to Inflammatory arthropathy, Osteoarthropathy, Fractures, Acquired flatfoot resulting from loss of the supporting structures of the medial longitudinal arch. Dysfunction of the tibialis posterior tendon Tear of the spring (calcaneoanvicular) ligament (rare). Tibialis anterior rupture (rare). Painful flatfoot can have other causes, such as tarsal coalition, but as such a patient will not present with a change in the shape of the foot these are not included here.
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.
The adult acquired flatfoot, secondary to posterior tibial tendon dysfunction, is diagnosed in a number of ways with no single test proven to be totally reliable. The most accurate diagnosis is made by a skilled clinician utilizing observation and hands on evaluation of the foot and ankle. Observation of the foot in a walking examination is most reliable. The affected foot appears more pronated and deformed compared to the unaffected foot. Muscle testing will show a strength deficit. An easy test to perform in the office is the single foot raise. A patient is asked to step with full body weight on the symptomatic foot, keeping the unaffected foot off the ground. The patient is then instructed to “raise up on the tip toes” of the affected foot. If the posterior tibial tendon has been attenuated or ruptured, the patient will be unable to lift the heel off the floor and rise onto the toes. In less severe cases, the patient will be able to rise on the toes, but the heel will not be noted to invert as it normally does when we rise onto the toes. X-rays can be helpful but are not diagnostic of the adult acquired flatfoot. Both feet – the symptomatic and asymptomatic – will demonstrate a flatfoot deformity on x-ray. Careful observation may show a greater severity of deformity on the affected side.
Non surgical Treatment
Non-surgical treatment consists of custom orthoses and or special bracing devices along with supportive measures aimed at reducing the symptoms. While non-surgical treatment helps the majority of patients with PTTD, progressive cases may require surgical treatment including soft tissue tendon transfers, osteotomies and lastly fusion.
Surgery is usually performed when non-surgical measures have failed. The goal of surgery is to eliminate pain, stop progression of the deformity and improve a patient?s mobility. More than one technique may be used, and surgery tends to include one or more of the following. The tendon is reconstructed or replaced using another tendon in the foot or ankle The name of the technique depends on the tendon used. Flexor digitorum longus (FDL) transfer. Flexor hallucis longus (FHL) transfer. Tibialis anterior transfer (Cobb procedure). Calcaneal osteotomy – the heel bone may be shifted to bring your heel back under your leg and the position fixed with a screw. Lengthening of the Achilles tendon if it is particularly tight. Repair one of the ligaments under your foot. If you smoke, your surgeon may refuse to operate unless you can refrain from smoking before and during the healing phase of your procedure. Research has proven that smoking delays bone healing significantly.