Patellar tracking disorder occurs when the kneecap (patella) shifts out of place as the leg bends or straightens. The kneecap is usually 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, helping it move smoothly in a groove in your thighbone.
There are a number of possible causes for a patellar tracking disorder including an abnormally shaped patella, muscles or tendons that are too tight or too loose, cartilage damage, overuse, or a severe blow to the knee.
This disorder can cause discomfort and pain, especially when bending your knee. It may also cause a popping, grinding, slipping, or catching sensation in the kneecap when bending or straightening your leg. Additionally, you may experience your knee buckling or giving way under the weight of your body.
Applying ice, resting and taking over-the-counter pain medications is usually the first line of treatment. Additionally, your physician may recommend stretches and muscle-strengthening exercises, tell you to tape or brace your knee, or advise that you lose excess weight. For the most severe cases surgery may be required to properly heal your knee.
Reference: WebMD; “Patellar Tracking Disorder – Topic Overview”; April 15, 2010; http://www.webmd.com/pain-management/knee-pain/tc/patellar-tracking-disorder-topic-overview