Adult acquired flatfoot deformity or posterior tibial tendon dysfunction is a gradual but progressive loss of ones arch. The posterior tibial muscle is a deep muscle in the back of the calf. It has a long tendon that extends from above the ankle and attaches into several sites around the arch of the foot. The muscle acts like a stirrup on the inside of the foot to help support the arch. The posterior tibial muscle stabilizes the arch and creates a rigid platform for walking and running. If the posterior tibial tendon becomes damaged or tears the arch loses its stability and as a result, collapses causing a flatfoot. Adult flatfoot deformity can occur in people of all ages and gender however, it occurs most commonly in sedentary middle aged to elderly females. There are several risk factors for posterior tibial tendon dysfunction that include: obesity, steroid use, systemic inflammatory diseases such as rheumatoid arthritis, trauma, being born with a low arch, and diabetes. It occurs most commonly in one foot however, it can occur in both feet especially in people with systemic diseases such as diabetes and rheumatoid arthritis.
Adult acquired flatfoot is caused by inflammation and progressive weakening of the major tendon that it is responsible for supporting the arch of the foot. This condition will commonly be accompanied by swelling and pain on the inner portion of the foot and ankle. Adult acquired flatfoot is more common in women and overweight individuals. It can also be seen after an injury to the foot and ankle. If left untreated the problem may result in a vicious cycle, as the foot becomes flatter the tendon supporting the arch structure becomes weaker and more and more stretched out. As the tendon becomes weaker, the foot structure becomes progressively flatter. Early detection and treatment is key, as this condition can lead to chronic swelling and pain.
The symptoms of PTTD may include pain, swelling, a flattening of the arch, and an inward rolling of the ankle. As the condition progresses, the symptoms will change. For example, when PTTD initially develops, there is pain on the inside of the foot and ankle (along the course of the tendon). In addition, the area may be red, warm, and swollen. 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.
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
The following is a summary of conservative treatments for acquired flatfoot. Stage 1, NSAIDs and short-leg walking cast or walker boot for 6-8 weeks; full-length semirigid custom molded orthosis, physical therapy. Stage 2, UCBL orthosis or short articulated ankle orthosis. Stage 3, Molded AFO, double-upright brace, or patellar tendon-bearing brace. Stage 4, Molded AFO, double-upright brace, or patellar tendon-bearing brace.
Surgical intervention for adult acquired flatfoot is appropriate when there is pain and swelling, and the patient notices that one foot looks different than the other because the arch is collapsing. As many as three in four adults with flat feet eventually need surgery, and it?s better to have the joint preservation procedure done before your arch totally collapses. In most cases, early and appropriate surgical treatment is successful in stabilizing the condition.