Posterior tibial tendon dysfunction (PTTD) is a condition that results in inflammation or tearing of the posterior tibial tendon. The posterior tibial tendon connects one of the calf muscles to the bones located on the inner foot. As a result, PTTD causes flatfoot because the tendon isn’t able to support the arch of the foot. According to the American Academy of Orthopaedic Surgeons, flatfoot is when the arch of the foot is fallen and the foot points outwards.
PTTD is also known as adult acquired flatfoot. Doctors can usually treat this condition without surgery, but sometimes surgery is necessary to repair the tendon.
Causes and Risk Factors
The posterior tibial tendon can sustain injury as a result of impact, such as a fall or contact while playing sports. Overuse of the tendon over time can also cause injury. Common activities that cause an overuse injury include:
- climbing stairs
- high-impact sports
PTTD is more likely to occur in:
- people over the age of 40
- people who are overweight or obese
- people with hypertension
PTTD usually occurs only in one foot, though in some cases it can occur in both feet. 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 worsens 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 ankle.
Your doctor will begin by examining your foot. They may look for swelling along the posterior tibial tendon. Your doctor will also test your range of motion by moving your foot 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. They’ll look for a collapsed arch and a heel that has shifted outward. Your doctor may also check how many toes they can see 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, they can see more than the fourth and fifth toes. Sometimes even all the toes are visible.
You may also need to stand on the leg that’s bothering you and to try to stand up on your tiptoes. Usually, an individual with PTTD won’t be able to do this.
Most doctors can 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. Your doctor may order X-rays or CT scans if they think you have arthritis in the foot or ankle. MRI and ultrasound scans can confirm PTTD.
Most cases of PTTD are treatable without surgery.
Reducing Swelling and Pain
Initial treatment helps reduce pain and swelling and allows your tendon to heel. Applying ice to the sore area and 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 can help take tension off the tendon and allow it to heal more quickly. This is helpful for mild to moderate PTTD or PTTD that occurs with arthritis.
Custom orthotics help support the foot and restore the normal foot position. Orthotics are helpful 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. Individuals usually wear this for six to eight weeks. It allows the tendon to get the rest that’s sometimes necessary for healing. However, this can also cause muscle atrophy or weakening of the muscles, so doctors only recommend it for severe cases.
Surgery may be necessary if the PTTD is severe and other treatments haven’t been successful. There are different surgical options, depending on your symptoms and the extent of your injury. If you’re having trouble moving your 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 called an osteotomy or surgery that fuses joints together may be necessary to correct a flatfoot.