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 patellar tracking disorder?
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.