Chronic posterior tibial tendon insufficiency can result in acquired adult flatfoot deformity. This is a chronic foot condition where the soft-tissues (including the posterior tibial tendon, deltoid and spring ligaments) on the inside aspect of the ankle are subject to repetitive load during walking and standing. Over time these structures may become painful and swollen ultimately failing. When these supporting structures fail the result is a change in the alignment of the foot. This condition is typically associated with a progressive flatfoot deformity. This type of deformity leads to increased strain on the supporting structures on the inside of the ankle and loading through the outer aspect of the ankle and hind-foot. Both the inside and outside of the ankle can become painful resulting significant disability. This condition can often be treated without surgery by strengthening the involved muscles and tendons and by bracing the ankle. When non-operative treatment fails, surgery can improve the alignment replace the injured tendon. Alignment and function can be restored, however, the time to maximal improvement is typically six months but, can take up to a year.
Several risk factors are associated with PTT dysfunction, including high blood pressure, obesity, diabetes, previous ankle surgery or trauma and exposure to steroids. A person who suspects that they are suffering from PTT dysfunction should seek medical attention earlier rather than later. It is much easier to treat early and avoid a collapsed arch than it is to repair one. When the pain first happens and there is no significant flatfoot deformity, initial treatments include rest, oral anti-inflammatory medications and, depending on the severity, a special boot or brace.
The symptoms of PTTD may include pain, swelling, a flattening of the arch, and inward rolling of the ankle. As the condition progresses, the symptoms will change. For example, later, as the arch begins to flatten, there may still be pain on the inside of the foot and ankle. But at this point, the foot and toes begin to turn outward and the ankle rolls inward. As PTTD becomes more advanced, the arch flattens even more and the pain often shifts to the outside of the foot, below the ankle. The tendon has deteriorated considerably and arthritis often develops in the foot. In more severe cases, arthritis may also develop in the ankle. Symptoms, which may occur in some persons with flexible flatfoot, include. Pain in the heel, arch, ankle, or along the outside of the foot. ?Turned-in? ankle. Pain associated with a shin splint. General weakness / fatigue in the foot or leg.
The diagnosis of tibialis posterior dysfunction is essentially clinical. However, plain radiographs of the foot and ankle are useful for assessing the degree of deformity and to confirm the presence or absence of degenerative changes in the subtalar and ankle articulations. The radiographs are also useful to exclude other causes of an acquired flatfoot deformity. The most useful radiographs are bilateral anteroposterior and lateral radiographs of the foot and a mortise (true anteroposterior) view of the ankle. All radiographs should be done with the patient standing. In most cases we see no role for magnetic resonance imaging or ultrasonography, as the diagnosis can be made clinically.
Non surgical Treatment
Conservative (nonoperative) care is advised at first. A simple modification to your shoe may be all that???s needed. Sometimes purchasing shoes with a good arch support is sufficient. For other patients, an off-the-shelf (prefabricated) shoe insert works well. The orthotic is designed specifically to position your foot in good alignment. Like the shoe insert, the orthotic fits inside the shoe. These work well for mild deformity or symptoms. Over-the-counter pain relievers or antiinflammatory drugs such as ibuprofen may be helpful. If symptoms are very severe, a removable boot or cast may be used to rest, support, and stabilize the foot and ankle while still allowing function. Patients with longer duration of symptoms or greater deformity may need a customized brace. The brace provides support and limits ankle motion. After several months, the brace is replaced with a foot orthotic. A physical therapy program of exercise to stretch and strengthen the foot and leg muscles is important. The therapist will also show you how to improve motor control and proprioception (joint sense of position). These added features help prevent and reduce injuries.
Until recently, operative treatment was indicated for most patients with stage 2 deformities. However, with the use of potentially effective nonoperative management , operative treatment is now indicated for those patients that have failed nonoperative management. The principles of operative treatment of stage 2 deformities include transferring another tendon to help serve the role of the dysfunctional posterior tibial tendon (usually the flexor hallucis longus is transferred). Restoring the shape and alignment of the foot. This moves the weight bearing axis back to the center of the ankle. Changing the shape of the foot can be achieved by one or more of the following procedures. Cutting the heel bone and shifting it to the inside (Medializing calcaneal osteotomy). Lateral column lengthening restores the arch and overall alignment of the foot. Medial column stabilization. This stiffens the ray of the big toe to better support the arch. Lengthening of the Achilles tendon or Gastrocnemius. This will allow the ankle to move adequately once the alignment of the foot is corrected. Stage 3 acquired adult flatfoot deformity is treated operatively with a hindfoot fusion (arthrodesis). This is done with either a double or triple arthrodesis – fusion of two or three of the joints in hindfoot through which the deformity occurs. It is important when a hindfoot arthrodesis is performed that it be done in such a way that the underlying foot deformity is corrected first. Simply fusing the hindfoot joints in place is no longer acceptable.