What is Patellar Instability? Learn More about your Knee Cap

Patellar instability or patellar subluxation happens when your kneecap does not slide evenly in your femoral groove area.

The patella, commonly referred to as the knee cap, is comprised of three bones that join together to create what is called your knee joint.

As your knee bends and straightens back out, the patella shifts up and down a groove in the femur called the trochlea.  A coating of articular cartilage on the patella and the trochlea helps to make the knee slide more smoothly.

If the patella shifts completely out of the trochlea, it is referred to as patellar dislocation. If the patella comes partially out of the trochlea, it is called patellar subluxation or patellar instability.

Patellar instability can be caused by a variety of things including biological factors (people who have wider pelvis areas) or those who have a more shallow trochlea are prone to patellar subluxation. Unusual gaits and abnormalities in the soft tissue may also lead to patellar instability.

In addition, if a person has repeatedly suffered from patellar dislocations following a direct blow to the knee, the patellar may become displaced. People who are “double jointed” may also be more likely to experience patellar instability.

Patellar instability may be mild, moderate or more severe, and it is generally quite painful. Patellar instability may also limit a person’s physical activities. The pain from patellar instability most frequently occurs when people are climbing or getting up after sitting down in a chair.

Following patellar instability, a person’s knee may be tender and swollen. Treating patellar instability depends largely on the severity of a person’s condition. Treatment may include using some type of brace to provide stability to the patella. Physical therapy may also be helpful.

In addition, certain exercises are sometimes recommended to treat patellar instability which help to make the quadricep muscles stronger. On occasion, surgical intervention for patellar instability is recommended.

If you think you might have patellar instability, you should consult the help of a board certified orthopedic surgeon like Dr. Stacie Grossfeld with Orthopaedic Specialists for a thorough evaluation. For more information, call Orthopaedic Specialists at: 502-212-2663 or visit us online at www.louisvlilebones.com.