Health Topics for Bones, Joints and Muscles

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Patellofemoral syndrome

Patellofemoral syndrome, sometimes called chondromalacia, causes pain in the knee. It is caused by overuse of the knee. It is a common problem of active young adults and teenagers, especially girls. Softening of the cartilage under the kneecap causes the pain. This can happen from overuse, injury, or weak muscles. If the kneecap does not move smoothly over the lower end of the thigh bone as the knee is bent or straightened, it can cause the cartilage to wear away.

Symptoms begin with a dull pain that starts slowly in the front of the knee. There may be a grating or grinding feeling when the leg is straightened. There is usually some tenderness. When the knee is not being used, there may not be any pain. The pain will be worse when using stairs or when standing after sitting. A healthcare provider should see anyone with knee pain to make sure what the cause is.

Treatment for this problem starts with rest of the knee. This means no sports activity for several weeks until the pain is better. Non-steroidal anti-inflammatory drugs (NSAIDs) may be used for the pain. Aspirin or medicines that have aspirin in them should not be given to anyone younger than 18 years of age. Taking aspirin is a risk for a serious illness called Reye's syndrome. Non-steroidal anti-inflammatory drugs (NSAIDs) should be taken with food or milk to prevent stomach upset. NSAIDs should be avoided by anyone who has been diagnosed with asthma, ulcer disease, or a bleeding disorder. Taking NSAIDs increases the risk of bleeding with trauma, dental work, surgery, or if taking blood thinners (anticoagulants).

Exercise, such as swimming or riding a stationary bike, improves the strength of the front thigh muscles. The knee should not be bent more than 90 degrees when doing these exercises. It may be necessary to have an arthroscopy of the knee to smooth the knee cartilage. Arthroscopy is a surgery done with a small lighted telescope to look into the knee joint.

It may take 6 weeks or more for the pain to go away. The best way to prevent this knee pain is to make sure the thigh muscles are strong before playing a sport using these muscles. Warming up and stretching before exercise or a sports activity is always important.

Last Reviewed 2005

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

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