Anterior knee pain

Definition

Anterior knee pain is pain that occurs at the front and center of the knee.

Alternative Names

Runner's knee; Patellofemoral pain; Patellar tendinitis; Tendinitis - patellar; Jumper's knee

Considerations

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:

• The patellar tendon (where the kneecap attaches to the shin bone)
• The quadriceps tendon (where the thigh muscles attach to the top of the kneecap)

Anterior knee pain refers to a number of different conditions. These include runner's knee (sometimes called patellar tendinitis) and chondromalacia of the patella.

Anterior knee pain is more common in:

• Adolescents and healthy young adults, especially girls
• People who are overweight
• Runners, jumpers, skiers, bicyclists, and soccer players, who exercise often

Causes

The pain often comes from strained tendons (tendinitis) and irritation or softening of the cartilage that lines the underside of the kneecap (chondromalacia patellae).

These problems begin when the kneecap does not move properly and rubs against the lower part of the thigh bone. This may happen because:

• You have flat feet
• The kneecap and the two other bones that make up the knee joint don't line up well (this is called poor alignment of the patellofemoral joint)
• There is tightness or weakness of the muscles on the front and back of your thigh
• You've done too much activity, which places extra stress on the kneecap (such as running, jumping or twisting, skiing, and playing soccer)

Other possible cause of anterior knee pain include:

• Arthritis
• Cartilage injury
• Dislocation of the patella, which means the kneecap has been pulled out of place
• Fracture of the kneecap
• Pinching of the inner lining of the knee with knee movement (synovial impingement, or plica syndrome)

Symptoms

Anterior knee pain is a dull, aching pain that is most often felt:

• Behind the kneecap (patella)
• Below the kneecap
• On the sides of the kneecap

Symptoms may be more noticeable with:

• Deep knee bends
• Going down stairs
• Running downhill
• Standing up after sitting for a while

First Aid

Treatment of anterior knee pain involves resting the knee and not running until you can do so without pain.

Apply ice. Try acetaminophen or ibuprofen for pain and swelling (but you may want to check with your health care provider first).

Tests such as x-rays or MRI scans are rarely needed.

Surgery for pain behind the kneecap (anterior knee pain) is rarely needed.

Do Not

Call immediately for emergency medical assistance if

Call your health care provider if knee pain does not go away, in spite of resting the joint.

Prevention

Stretch the muscles on the back (hamstrings) and front (quadriceps) of your upper leg.

• Your primary care provider, a sports medicine specialist, or a physical therapist can show you stretches to try.
• Before you stretch, warm up for 5 minutes.
• Also stretch after you are done exercising.

Your health care provider can also teach you ways to strengthen these muscles. 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:

• Avoid running straight down hills; walk down instead
• Bicycle or swim instead of running
• Reduce the amount of exercise you do
• Run on a smooth, soft surface, such as a track, rather than on cement

Other techniques are:

• Special shoe inserts and support devices (orthotics) may help people with flat feet
• Taping to realign the kneecap can help prevent symptoms

Make sure your running shoes:

• Are made well
• Fit well
• Have good cushion

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References

De Carlo M, Armstrong B. Rehabilitation of the knee following sports injury. Clin Sports Med. 2010;29:81-106.

Dixit S, DiFiori JP, Burton M, Mines B. Management of patellofemoral pain syndrome. Am Fam Physician. 2007;75:194-202.

May TJ. Persistent anterior knee pain. Am Fam Physician. 2007;76:277-278.

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 Drez's Orthopaedic Sports Medicine. 3rd ed. Philadelphia, Pa: Saunders Elsevier;2009:chap 22:sect C.