PTTD Diagnosis: How Doctors Identify Posterior Tibial Tendon Dysfunction

You’ve been dealing with ankle pain for weeks—maybe months. It’s worse in the morning, it hurts when you walk, and your arch seems to be falling. You’ve started googling your symptoms and PTTD keeps coming up. Now you’re wondering: how do I know for sure if I have this?

Getting a proper diagnosis is the first step toward feeling better. Here’s what to expect when you see a doctor about possible PTTD.

What happens at the appointment

Your appointment will start like most medical visits: you’ll answer questions about your symptoms. Be ready to describe when the pain started, what makes it worse, what makes it better, and how it’s affecting your daily life. The doctor will ask about any injuries, your activity level, and your medical history.

This matters because PTTD can develop after an injury, but it can also come on gradually without a specific trigger. Your answers help the doctor narrow down what’s going on.

After the questions comes the physical exam. This is the most important part of diagnosing PTTD.

Physical exam tests

A skilled foot specialist can often diagnose PTTD just by examining your foot and watching you move. Here are the specific tests they might do:

Visual inspection

The doctor will look at your foot from several angles. They’re checking for swelling along the inside of your ankle (where the posterior tibial tendon runs), flattening of your arch, and any outward rotation of the foot. They might compare your affected foot to your other one to see differences.

The “too many toes” sign

This is exactly what it sounds like. When you have PTTD, your foot rolls outward (pronates), which causes your toes to point away from your body. When viewed from behind, more of your toes become visible than normal—hence “too many toes.” It’s a classic sign of PTTD and flatfoot deformity.

Single limb heel rise

You’ll be asked to stand on one foot and rise up onto your toes. This sounds simple, but it’s actually a very telling test. The posterior tibial tendon is crucial for this movement. If you have PTTD, you’ll have difficulty or be unable to do this on the affected side. The doctor might also watch to see if your arch collapses when you try this.

Range of motion testing

The doctor will move your ankle and foot through its range of motion, checking for stiffness, pain, and weakness. They’ll assess how much you can point your toes down (plantarflexion) and pull your foot up (dorsiflexion).

Palpation

Your doctor will feel along the course of the posterior tibial tendon to check for tenderness, thickening, or gaps in the tendon. Pain and tenderness in this specific location is a strong indicator.

Imaging tests

While the physical exam is crucial, imaging helps confirm the diagnosis and shows the doctor exactly what’s happening inside your foot.

X-rays

These are usually the first imaging test ordered. X-rays show the bones and joints, revealing any arthritis, deformities, or misalignment. They can’t show the tendon itself, but they show the consequences of tendon dysfunction—like arch collapse or joint changes.

MRI (magnetic resonance imaging)

An MRI shows soft tissues, including the tendon itself. This is the best test for evaluating tendon damage—tears, inflammation, or degeneration show up clearly. It also shows any associated conditions, like synovitis or bursitis.

Ultrasound

Dynamic ultrasound lets the doctor watch the tendon while you move your foot. This can show tendon function in real-time, revealing subluxation (partial dislocation) or abnormal movement patterns. It’s less invasive than an MRI and often cheaper.

CT scans

These are less commonly used for PTTD but can be helpful in complex cases, especially when planning surgery. CT gives very detailed images of bone structure.

Finding the right specialist

Not all doctors are equally experienced with PTTD. For the best care, look for:

A podiatrist with foot and ankle surgery credentials, or an orthopedic surgeon who specializes in foot and ankle conditions. These specialists deal with PTTD regularly and know what to look for.

Don’t be afraid to ask about their experience: “How many PTTD cases do you see per year?” and “What percentage of them need surgery?” You want someone who sees this regularly, not occasional cases.

If you’re unsure, ask your primary care doctor for a referral to a specialist. They usually know who the go-to experts are in your area.

Questions to ask your doctor

Come prepared with questions. Here are some important ones:

  • What stage is my PTTD?
  • What treatment options do I have at this stage?
  • What happens if I don’t treat it?
  • Do I need imaging, and if so, what kind?
  • How long do you expect conservative treatment to take before we know if it’s working?
  • What would indicate that surgery is necessary?

The answers to these questions will help you understand your situation and make informed decisions about your care.

Sources

  • Mayo Clinic diagnosis guidelines
  • American College of Foot and Ankle Surgeons
  • Research literature on PTTD clinical presentation

Disclaimer: This content is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider for diagnosis and treatment of any medical condition.