What Is PTTD?

The posterior tibial tendon serves as one of the major supporting structures of the foot, helping to support the arch while walking. Posterior tibial tendon dysfunction (PTTD) is a condition caused by changes in the tendon, impairing its ability to support the arch. This results in flattening of the foot.

PTTD is often called Acquired Adult Flatfoot Deformity (AAFD)  because it is the most common type of flatfoot developed during adulthood. Although this condition typically occurs in only one foot, some people may develop it in both feet. This condition progresses from early stages with pain along the posterior tibial tendon to advanced deformity and arthritis throughout the hindfoot and ankle.

Causes

Except for the rare exception, there is often no specific event, such as an acute injury, that causes the problem. More commonly, the tendon becomes injured from cumulative wear and tear. Posterior tibial tendon dysfunction occurs more commonly in patients who already have a flat foot.  As the arch flattens, more stress is placed on the posterior tibial tendon and also on the ligaments on the inside of the foot and ankle.

Symptoms

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.

At certain stages of this disorder, pain may shift from the inside to the outside aspect of the ankle as the heel shifts outward and structures are pinched laterally. As PTTD becomes more advanced, the arch flattens even more and the pain often is noted at both sides of the hindfoot and often perceived as ‘ankle pain.” As the conditions deteriorates , arthritis often develops in the hindfoot joints making walking difficult. In the most severe cases, arthritis may also develop in the ankle.

Nonsurgical Treatment

Because of the progressive nature of PTTD, early treatment is advised. If treated early enough, your symptoms may resolve without the need for surgery, and progression of your condition can be arrested.

In contrast, untreated PTTD could leave you with an extremely flat foot, painful arthritis in the foot and ankle and increasing limitations on walking, running or other activities.

In many cases of PTTD, treatment can begin with nonsurgical approaches that may include:

• Orthotic devices or bracing. To give your arch the support it needs, your foot and ankle surgeon may provide you with an ankle brace or a custom orthotic device that fits into the shoe.
• Immobilization. Sometimes a short-leg cast or boot is worn to immobilize the foot and allow the tendon to heal, or you may need to completely avoid all weight bearing for a while.
• Physical therapy. Ultrasound therapy and exercises may help rehabilitate the tendon and muscle following immobilization.
• Medications. Nonsteroidal anti-inflammatory drugs (NSAIDs) or injections may help reduce the pain and inflammation.
• Shoe modifications. Your foot and ankle surgeon may advise changes to your shoes and may provide special inserts designed to improve arch support.

When Is Surgery Needed?

In cases  that are advanced or have failed to improve with nonsurgical treatment, surgery may be required. For cases involving arthritis, surgery may be the only option. Procedures may include ligament and muscle lengthening or repair,  tendon transfers, cutting and realigning bones, and joint fusions. In general, early stage disease may be treated with tendon and ligament procedures with the addition of osteotomies to realign the foot. Later stages with either a rigidly fixed deformity or with arthritis is often treated with fusion procedures.