Chondromalacia patella is the softening and breakdown of the tissue (cartilage) that lines the underside of the kneecap (patella).
It is a common cause of anterior knee pain.
Chondromalacia of the patella occurs in adolescents and young adults.
The condition is more common in females. It can be related to the abnormal position of the knee.
Your kneecap (patella) sits over the front of your knee joint. As you bend or straighten your knee, the underside of the patella glides over the bones that make up the knee.
Strong tendons help attach the patella to the bones and muscles that surround the knee. These tendons are called:
Problems begin when the kneecap does not move properly and rubs against the lower part of the thigh bone. This may occur because:
Chondromalacia of the patella can also be a sign of arthritis of the kneecap, which is usually seen in older people.
People who have previously had a dislocation, fracture, or other injury to the kneecap are more likely to develop chondromalacia.
The doctor will perform a physical examination. The knee may be tender and mildly swollen, and the kneecap may not be perfectly lined up with the femur (thigh bone).
When you flex your knee, you may feel a grinding sensation below the kneecap. Pressing the kneecap when the knee is straightening out may be painful.
X-rays are usually normal, although a special x-ray view of the kneecap may show signs of arthritis or tilting.
Temporarily resting the knee and taking nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, naproxen, or aspirin may help relieve pain. Physical therapy, especially quadriceps strengthening and hamstring stretching, may be helpful.
Stretch the muscles on the back (hamstrings) and front (quadriceps) of your upper leg.
Your health care provider can teach you ways to make these muscles tighter. Stronger muscles will help hold your kneecap in the correct position.
If you need to lose weight, find out how.
Changing the way you exercise may help:
Other techniques are:
Make sure your running shoes:
If the pain does not improve and there are signs of arthritis developing around the kneecap, surgery may be an option. Surgery may be done using:
During the surgery, kneecap cartilage that has been damaged may be removed. Changes may be made to the tendons to help the kneecap move more evenly.
Chondromalacia patella usually improves with therapy and use of NSAIDs. For the few people who need it, surgery is successful most of the time.
The main complication is failure of treatment to relieve pain.
When surgery is necessary, surgical complications may include:
Call for an appointment with your health care provider if you have symptoms of this disorder.
Patellofemoral syndrome; Knee pain - chondromalacia
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Steiner T, Parker RD. Patella: subluxation and dislocation. 2. Patellofemoral instability: recurrent dislocation of the patella. In: DeLee JC, Drez D Jr., Miller MD, eds. DeLee and Dree's Orthopaedic Sports Medicine. 3rd ed. Philadelphia, Pa: Saunders Elsevier;2009:chap 22:sect C.
Reviewed by: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; and C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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