What is Patellofemoral Pain Syndrome

Patellofemoral pain syndrome is a condition in which the tissue (cartilage) on the underside of the kneecap (patella) softens or breaks down. This causes pain in the front of the knee.

The condition is also called runner’s knee or chondromalacia patella. Patellofemoral pain syndrome is most common in young adults who are active in sports.

The knee is the largest joint in the body. The patella covers the front of the knee and is attached to muscles above and below the knee. The underside of the patella is covered with a smooth type of cartilage (synovium). The smooth surface helps the patella to glide easily when you move your knee. Patellofemoral pain syndrome causes swelling in the joint linings and bone surfaces in the knee.

What are the causes?

This condition may be caused by:

• Overuse of the knee.
• Poor alignment of your knee joints.
• Weak leg muscles.
• A direct blow to your kneecap.

What increases the risk?

You are more likely to develop this condition if:

• You do a lot of activities that can wear down your kneecap. These include:
  • Running.
  • Squatting.
  • Climbing stairs.
• You start a new physical activity or exercise program.
• You wear shoes that do not fit well.
• You do not have good leg strength.
• You are overweight.

What are the signs or symptoms?

The main symptom of this condition is knee pain. This may feel like a dull, aching pain underneath your patella, in the front of your knee. There may be a popping or cracking sound when you move your knee. Pain may get worse with:

• Exercise.
• Climbing stairs.
• Running.
• Jumping.
• Squatting.
• Kneeling.
• Sitting for a long time.
• Moving or pushing on your patella.

How is this diagnosed?

This condition may be diagnosed based on:

• Your symptoms and medical history. You may be asked about your recent physical activities and which ones cause knee pain.
• A physical exam. This may include:
  • Moving your patella back and forth.
  • Checking your range of knee motion.
  • Having you squat or jump to see if you have pain.
  • Checking the strength of your leg muscles.
• Imaging tests to confirm the diagnosis. These may include an MRI of your knee.

How is this treated?

This condition may be treated at home with rest, ice, compression, and elevation (RICE).

Other treatments may include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs).
• Physical therapy to stretch and strengthen your leg muscles.
• Shoe inserts (orthotics) to take stress off your knee.
• A knee brace or knee support.
• Adhesive tapes to the skin.
• Surgery to remove damaged cartilage or move the patella to a better position. This is rare.

Follow these instructions at home:

If you have a shoe or brace:

• Wear the shoe or brace as told by your health care provider. Remove it only as told by your health care provider.
• Loosen the shoe or brace if your toes tingle, become numb, or turn cold and blue.
• Keep the shoe or brace clean.
• If the shoe or brace is not waterproof:
  • Do not let it get wet.
  • Cover it with a watertight covering when you take a bath or a shower.

Managing pain, stiffness, and swelling

• If directed, put ice on the painful area.
  • If you have a removable shoe or brace, remove it as told by your health care provider.
  • Put ice in a plastic bag.
  • Place a towel between your skin and the bag.
  • Leave the ice on for 20 minutes, 2–3 times a day.
• Move your toes often to avoid stiffness and to lessen swelling.
• Rest your knee:
  • Avoid activities that cause knee pain.
  • When sitting or lying down, raise (elevate) the injured area above the level of your heart, whenever possible.

General instructions

• Take over-the-counter and prescription medicines only as told by your health care provider.
• Use splints, braces, knee supports, or walking aids as directed by your health care provider.
• Perform stretching and strengthening exercises as told by your health care provider or physical therapist.
• Do not use any products that contain nicotine or tobacco, such as cigarettes and e-cigarettes. These can delay healing. If you need help quitting, ask your health care provider.
• Return to your normal activities as told by your health care provider. Ask your health care provider what activities are safe for you.
• Keep all follow-up visits as told by your health care provider. This is important.

Contact a health care provider if:

• Your symptoms get worse.
• You are not improving with home care.

Summary

• Patellofemoral pain syndrome is a condition in which the tissue (cartilage) on the underside of the kneecap (patella) softens or breaks down.
• This condition causes swelling in the joint linings and bone surfaces in the knee. This leads to pain in the front of the knee.
• This condition may be treated at home with rest, ice, compression, and elevation (RICE).
• Use splints, braces, knee supports, or walking aids as directed by your health care provider.