What is patellofemoral pain syndrome?

Patellofemoral pain syndrome (PFPS) is a term to describe pain that occurs around your kneecap, or patella. It is also known as “runner’s knee” or “jumper’s knee.” This condition is more likely to develop if you participate in sports that involve frequent running and jumping, but it can also happen to non-athletes.

Typically, PFPS causes pain and stiffness in the front of the knee that can lead to difficulty with normal activities such as kneeling, squatting, going up and down stairs, and even getting up from a chair or couch.

runners stretching before a run in a park

Anatomy of a knee

The knee is a complex joint consisting of three bones, including the femur (thighbone), tibia (shinbone) and patella (kneecap). Four ligaments connect the femur and tibia. The patella is supported by the patellar tendon, which attaches it to the tibia, and the quadriceps tendon, which joins the kneecap to the quadriceps muscle.

The patella rides in the groove for the kneecap, called the trochlea. Both the patella and trochlea are lined with the thickest cartilage in the body, which provides cushioning and a smooth surface for the knee.

Diagram of the anatomy of a knee

Patellofemoral pain syndrome causes

Patellofemoral pain syndrome is often caused by overuse or knee alignment issues, resulting in pain at the front of the knee. Irritation of the bone or soft tissues around the kneecap triggers pain when nerves detect this irritation.

Common causes include:

  • Overuse: Repetitive activities like running and jumping, and sports such as tennis or pickleball can strain your knee.
  • Increased activity: Sudden changes in activity level, such as training for a race or starting a new workout, put extra stress on the knee, leading to pain.
  • Improper footwear: Worn-out shoes, especially with increased mileage, can contribute to discomfort. Replace your shoes every 6 months.
  • Change in surface: Switching to harder surfaces like concrete or artificial turf can aggravate knee pain.

Patella maltracking, when the kneecap shifts to one side, can increase pressure on the knee's soft tissues, causing PFPS. Contributing factors include:

  • Anatomic issues: Irregular patella shape or alignment can predispose you to PFPS.
  • Muscle imbalances: Weak quadriceps or tight hamstrings, along with weak hip and core muscles, can disrupt patella tracking, causing strain on the knee.

Patellofemoral pain syndrome symptoms

Knee pain from patellofemoral pain syndrome feels like a dull ache over the front of the knee. It comes about gradually over time and is typically related to sporting or aggravating activities. People may experience pain in one or both knees. It is also associated with stiffness and popping, cracking or crunching sounds.

The pain often worsens over the front of the knee with:

  • Repetitive knee bending from squatting or climbing stairs
  • Sitting with bent knees for significant periods, such as on long car rides or while working
  • Changing your training or playing on harder surfaces, such as concrete
  • Increasing your activity level or training intensity
  • Wearing new or different shoes during physical activity

Runner’s knee risk factors

Certain factors can increase your chances of developing patellofemoral pain syndrome. Some of these risk factors you can control. Others, however, you can’t change. Understanding the factors that can make patellofemoral pain syndrome more likely to occur can help you protect your knees and reduce your risk. Risk factors for PFPS include:

Diagnosing runner’s knee

To diagnose patellofemoral pain syndrome, your healthcare provider will likely ask about your knee history, gently press on your knee, and move your leg into different positions. In some cases, imaging tests may be used to help identify the cause of your knee pain.

Patellofemoral pain syndrome treatment

Your provider will decide which treatment makes the most sense for you based on your symptoms, the results of your physical exam and imaging tests, overall health and goals. Treatments range from lifestyle changes and at-home care to conservative treatments and, in rare situations, surgical options.

Locations

We offer several locations for your care, including specialty orthopedic centers in North and Central Texas.

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Frequently asked questions