Condition Basics

What is patellar tracking disorder?

Patellar tracking disorder means that the kneecap (patella) shifts out of place as the leg bends or straightens. In most cases, the kneecap shifts too far toward the outside of the leg. In a few people, it shifts toward the inside.

Your knee joint is a complex hinge that joins the two bones of the lower leg with the thighbone.

• The kneecap sits in a groove at the end of the thighbone. It is held in place by tendons on the top and bottom and by ligaments on the sides.
• A layer of cartilage lines the underside of the kneecap. This helps it glide along the groove in the thighbone.

A problem with any of these parts in or around the knee can lead to patellar tracking disorder.

What causes it?

Patellar tracking disorder is usually caused by several problems combined, such as:

• Weak thigh muscles.
• Tendons, ligaments, or muscles in the leg that are too tight or too loose.
• Activities that stress the knee again and again, especially those with twisting motions.
• A traumatic injury to the knee, such as a blow that pushes the kneecap toward the outer side of the leg.
• Problems with the structure of the knee bones or how they are aligned.

You are more likely to have patellar tracking disorder if you have any of the above problems and you are overweight, run, or play sports that require repeated jumping, knee bending, or squatting.

What are the symptoms?

If you have a patellar tracking problem, you may have:

• Pain in the front of the knee, especially when you squat, jump, kneel, or use stairs (most often when going down stairs).
• A feeling of popping, grinding, slipping, or catching in your kneecap when you bend or straighten your leg.
• A feeling that your knee is buckling or giving way, as though all of a sudden your knee can't support your weight.

If your kneecap is completely dislocated, you may have severe pain and swelling. Your knee may look like a bone is out of place. And you may not be able to bend or straighten the knee. If you have these symptoms, be sure to see your doctor. A dislocated kneecap needs to be put back in place by a doctor right away.

How is it diagnosed?

It can be hard to tell the difference between patellar tracking disorder and some other knee problems. To find out what problem you have, your doctor will:

• Ask questions about your past health, your activities, when the pain started, and whether it was caused by an injury, overuse, or something else.
• Feel, move, and look at your knee as you sit, stand, and walk.

You may have an X-ray so your doctor can check the position and condition of your knee bones. If more information is needed, you may have an MRI.

How is patellar tracking disorder treated?

Treatment can help to reduce your pain and to strengthen the muscles around your kneecap to help it stay in place. If you don't have severe pain, a week or two of rest and home care may help.

When your knee pain starts to decrease, your doctor may recommend physical therapy. A doctor or physical therapist can help you learn exercises to stretch and strengthen your leg and hip.

Your doctor or physical therapist may also suggest:

• Taping your knee to hold the kneecap in place.
• Using a knee brace for extra knee support.
• Trying shoe inserts (orthotics) to improve the position of your feet.

Patellar tracking disorder can be a frustrating problem, but be patient. Most people feel better after a few months of treatment. As a rule, the longer you have had this problem, the longer it will take to get better.

Surgery usually isn't needed.

How can you care for yourself when you have patellar tracking disorder?

Home care may help to reduce your pain.

• Take a break from activities that cause knee pain, like squatting, kneeling, running, and jumping.
• Put ice or a cold pack on your knee for 10 to 20 minutes at a time, especially before and after activity. Put a thin cloth between the ice and your skin. After 2 or 3 days, you can try heat to see if that helps.
• Ask your doctor if you can take an over-the-counter pain medicine, such as acetaminophen (Tylenol), ibuprofen (Advil, Motrin), or naproxen (Aleve). Be safe with medicines. Read and follow all instructions on the label.
• As your knee pain starts to decrease, do exercises to increase strength and flexibility in your leg and hip. Your doctor or a physical therapist can help you plan an exercise program that fits your condition.

How can you prevent it?

You can take steps to prevent patellar tracking disorder.

• Avoid activity that overloads and overuses the knee.
• Keep the muscles around your knees and hips strong and flexible.
• Stretch your legs and hips well, both before and after activity.
• Do activities that work different parts of the leg, especially if you're a runner. Cycling and swimming are good choices.
• Stay at a healthy weight to reduce stress on your knees.