Patellar tracking disorder is an imbalance in the knee area that causes the kneecap (patella) to shift or tilt out of place as the leg bends or straightens. Symptoms include a dull ache under or around the kneecap, or a popping, grinding, slipping, or catching sensation in the kneecap as the knee bends or extends.

Other symptoms of a patellar tracking disorder include swelling of the knee or a buckling or "giving way" of the knee, where the knee suddenly fails to support body weight. A patellar tracking disorder may be caused by a combination of things, including:

• 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 with how they are aligned.

Knee pain can be slow to heal. But most people who have patellar tracking disorder find relief with a few months of nonsurgical treatment, including rest from the aggravating activity, icing the knee, and nonsteroidal anti-inflammatory drugs (NSAIDs). After 2 or 3 days of using ice, you can try heat to see if it helps. Physical therapy and bracing or taping the knee can also help to relieve knee pain. In chronic or severe cases, surgery may be needed to realign the kneecap, restore normal tracking, and repair damage to the knee.