A variety of foot problems can lead to adult acquired flatfoot deformity (AAFD), a condition that results in a fallen arch with the foot pointed outward. Most people - no matter what the cause of their flatfoot - can be helped with orthotics and braces. In patients who have tried orthotics and braces without any relief, surgery can be a very effective way to help with the pain and deformity. This article provides a brief overview of the problems that can result in AAFD. Further details regarding the most common conditions that cause an acquired flatfoot and their treatment options are provided in separate articles. Links to those articles are provided.
There are numerous causes of acquired adult flatfoot, including fracture or dislocation, tendon laceration, tarsal coalition, arthritis, neuroarthropathy, neurologic weakness, and iatrogenic causes. The most common cause of acquired adult flatfoot is posterior tibial tendon dysfunction.
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
Initial treatment is based on the degree of deformity and flexibility at initial presentation. Conservative treatment includes orthotics or ankle foot orthoses (AFO) to support the posterior tibial tendon (PT) and the longitudinal arch, anti-inflammatories to help reduce pain and inflammation, activity modification which may include immobilization of the foot and physical therapy to help strengthen and rehabilitate the tendon.
Surgical treatment should be considered when all other conservative treatment has failed. Surgery options for flatfoot reconstruction depend on the severity of the flatfoot. Surgery for a flexible flatfoot deformity (flatfoot without arthritis to the foot joints) involves advancing the posterior tibial tendon under the arch to provide more support and decrease elongation of the tendon as well as addressing the hindfoot eversion with a osteotomy to the calcaneus (surgical cut in the heel bone). Additionally, the Achilles tendon may need to be lengthened because of the compensatory contracture of the Achilles tendon with flatfoot deformity. Flatfoot deformity with arthritic changes to the foot is considered a rigid flatfoot. Correction of a rigid flatfoot deformity usually involves surgical fusion of the hindfoot joints. This is a reconstructive procedure which allows the surgeon to re-position the foot into a normal position. Although the procedure should be considered for advanced PTTD, it has many complications and should be discussed at length with your doctor.