Posterior tibial tendon dysfunction (PTTD) is a condition that results in inflammation or tearing of the posterior tibial tendon. The posterior tibial tendon connects the calf muscle to the bones located on the inner foot. As a result, PTTD causes flat foot because the tendon is not able to support the arch of the foot.
PTTD may also be called “acquired adult flat foot.” This condition can usually be treated without surgery, but sometimes surgery is required to repair the tendon.
The posterior tibial tendon can be injured as a result of impact, such as a fall or contact while playing sports. Injury can also be caused over a period of time by overuse of the tendon. Common activities that cause an overuse injury include walking, running, hiking, climbing stairs, and high-impact sports. Certain people may be more prone to PTTD. PTTD is more likely to occur in:
Usually posterior tibial tendon dysfunction occurs only in one foot, though in some cases both feet may be affected. Symptoms of PTTD include:
- pain, typically around the inside of the foot and ankle
- swelling, warmth, and redness along the inside of the foot and ankle
- pain that is worse during activity
- flattening of the foot
- inward rolling of the ankle
- turning out of the toes and foot
As PTTD progresses, the location of the pain may change. This is because, as the problem progresses, your foot flattens and your heel bone shifts. Pain may now be felt around the outside of your ankle and foot. The changes to the posterior tibial tendon can cause arthritis in your foot and, sometimes, your ankle.
Your doctor will begin by examining your foot. He or she may look for swelling along the posterior tibial tendon. Your doctor will also test your range of motion by moving your foot from side to side and up and down. PTTD can cause problems with side-to-side range of motion, as well as issues with moving the toes toward the shinbone.
Your doctor will also look at the shape of your foot. He or she will look for a collapsed arch and a heel that has shifted outward. Your doctor may also look to see how many toes can be seen from behind your heel when you’re standing. Normally only the fifth toe and half of the fourth toe are visible from this angle. In PTTD, however, more than the fourth and fifth toes can be seen—sometimes even all the toes are visible.
You may also be asked to stand on the leg that is bothering you and to try to stand up on your tiptoes. Usually, an individual with PTTD will not be able to do this.
Most doctors are able to diagnose problems with the posterior tibial tendon by examining the foot, but your doctor may also order some imaging tests to confirm the diagnosis and rule out other conditions. X-rays or computed tomography (CT) scans may be ordered if the doctor suspects arthritis in the foot or ankle. Magnetic resonance imaging (MRI) and ultrasound scans can be ordered to confirm PTTD.
Most cases of PTTD can be treated without surgery.
Reducing Swelling and Pain
Initial treatment is designed to help reduce pain and swelling, as well as allow the tendon to heel. Applying ice to the sore area, as well as taking nonsteroidal anti-inflammatory medications (NSAIDs), can help reduce swelling and pain. Your doctor will also advise you to rest and avoid activities that cause pain, such as running and other high-impact activities.
Depending on the severity of your PTTD, your doctor may suggest some form of support for your foot and ankle. An ankle brace may be recommended to help take tension off the tendon and allow it to heal more quickly. This may be used for mild to moderate PTTD, or PTTD occurring with arthritis.
Custom orthotics may also be suggested to help support the foot and restore the normal foot position. Orthotics can be used for mild to severe PTTD. If the injury to your posterior tibial tendon is severe, your foot and ankle may require immobilization using a short walking boot. This is usually worn for six to eight weeks and allows the tendon to get the rest that is sometimes necessary for healing. However, this can also cause muscle atrophy or weakening of the muscles, so it is only used in severe cases.
Surgery may be required if the PTTD is severe and other treatments have not been successful. There are a number of different surgical options, depending on your symptoms and extent of injury. If you are having trouble moving the ankle, a surgical procedure that helps lengthen the calf muscle may be an option. Other options include surgeries that remove damaged areas from the tendon or replace the posterior tibial tendon with another tendon from the body. In more serious cases of PTTD, surgery that cuts and moves the bones (osteotomy) or surgery that fuses joints together may be necessary to correct a flat foot.