Skip to Content

Popliteal Artery Entrapment Syndrome (PAES)

Popliteal artery entrapment syndrome (PAES) is a rare vascular condition of the leg. It happens when tendons and muscles squeeze the knee's main (popliteal) artery, limiting blood flow to the lower leg.

PAES tends to affect male athletes under 30, largely runners. It causes symptoms — most often during a workout — such as pain, numbness, or cramping in the calf. Left untreated, PAES can cause lasting nerve or muscle damage.

At UPMC, our surgeons are experts at diagnosing PAES and performing vascular surgery to relieve symptoms.

Looking for Popliteal Artery Entrapment Syndrome (PAES) Care?

On this page

What Is PAES?

Popliteal artery entrapment syndrome, also called PAES, is a rare vascular disease.

The popliteal artery is the main artery that runs through and behind your knee.

PAES occurs when nearby tendons and muscles squeeze — or compress — the popliteal artery. This limits blood flow, leading to symptoms in the lower leg.

How common is PAES?

PAES is a rare vascular disease.

What are the types of PAES?

There are six different types of PAES:

  • Type I — Caused by an abnormal course of the popliteal artery.
  • Type II — Caused by an abnormal position of a nearby muscle.
  • Type III — Caused by a slip of a nearby muscle and fibrous bands of tissue.
  • Type IV — Caused when the popliteal artery passes underneath the popliteus muscle.
  • Type V — Caused by compression of the popliteal artery and the popliteal vein.
  • Type VI — Includes other variations.

What causes PAES?

PAES is often a congenital problem, meaning you're born with the condition. An enlarged calf muscle can also cause PAES to form over time.

What are PAES risk factors and complications?

PAES risk factors

PAES is most common in young athletes, largely those who play soccer, football, rugby, or vigorously lift weights.

Men more likely to get PAES than women.

Complications of PAES

In some cases, compression from PAES can damage and narrow the wall of the popliteal artery.

In severe cases, permanent muscle or nerve damage can occur due to compression or loss of blood flow to the lower leg.

How can I prevent PAES?

PAES is most often congenital, meaning it is present at birth. There is nothing you can do to prevent PAES.

Back to top


What Are the Signs and Symptoms of PAES?

PAES symptoms may include:

  • Coolness in the foot and calf.
  • Discoloration of the toes and toenails.
  • Pain, numbness, tiredness, or cramping in the calf during exercise.
  • Swelling in the leg.

Often, symptoms improve after a few minutes of rest but return during exercise.

When should I see a doctor about my PAES symptoms?

If you have symptoms of PAES, you should schedule an appointment with your doctor. Although PAES is not an emergency, if left untreated, it can cause permanent damage to your popliteal artery, nerves, or muscles.

Back to top


How Do You Diagnose PAES?

In most cases, your doctor can diagnose PAES during a physical exam. You may need other tests to confirm the diagnosis.

What to expect during your visit

To diagnose PAES, your UPMC vascular surgeon will:

  • Ask you about your symptoms.
  • Learn about your medical history.
  • Perform a physical exam.

Tests to diagnose PAES

Your doctor may use the following tests to confirm a diagnosis of PAES:

  • Ankle-brachial index with exercise — This test measures blood pressure in your arms and legs before and after exercise.
  • Computerized tomography (CT) angiography — This test uses cross-sectional x-rays and a computer to create detailed 3D images.
  • Magnetic resonance angiography (MRA) — This test uses a large magnetic field, radio waves, and computers to make detailed pictures of your blood vessels and blood flow.
  • Ultrasound — This noninvasive imaging test uses sound waves to create images of blood flow through your blood vessels.

PAES prognosis

After PAES surgery, most people make a full recovery with a low risk of recurrence. Most athletes are able to return to their sport.

Back to top


How Do You Treat PAES?

At UPMC, our vascular surgeons offer expert treatment for PAES. Based on the severity of your condition, we will work with you to determine if surgical care is right for you.

Surgery for condition

Your UPMC vascular surgeon can treat PAES through open surgery to release the compression of the popliteal artery.

Most people only spend 1-2 days in the hospital after surgery and don't need physical therapy after they return home. The majority of patients make a full recovery within four weeks.

How effective is treatment?

PAES surgery successfully relieves symptoms in more than 90 percent of people. However, if you have damage to your popliteal artery, you may have pain in your legs when you exercise, even after surgery.


Last reviewed by a UPMC medical professional on 2024-10-01.