Patellar Instability/Dislocated Knee Cap

The patella (knee cap) is usually sitting right where it needs to be, in a groove at the of your thighbone (femur). As your knee bends and straightens, the patella slides up and down within the groove, allowing it to function properly. But what happens when the patella slides too far to one side or the other?

The knee cap then becomes unstable, and depending on the severity of the injury, could even become dislocated. This condition is known as patella instability. If left untreated, the likelihood of permanent damage and even more pain could increase.

What is Patellar Instability?

Patellar instability occurs when the knee cap moves outside of the groove. It’s a common injury for children and adolescents because some may have ligaments that are looser, making their joints very flexible and more prone to knee dislocations. Some adults can even experience patellar instability as well. There are two common ways this injury occurs:

During an accident

Also known as a traumatic event, the kneecap can slip out of place if you or your child has suffered from a hard blow or fall. The injury is more common in children who play high-contact sports, such as football. During the accident, the kneecap may slide out of place quickly and go back into place on its own immediately after it slides out. There may be a lot of pain and swelling in front of the knee after this happens, making it necessary to seek medical treatment. Orthopaedic surgeon Nathaniel Wingert, MD will be able to determine if the patella is completely or partially dislocated.

The kneecap dislocates by itself

Also known as an atraumatic event, meaning no specific injury has taken place. When your child’s patella slides out of the groove on its own, that usually means that the groove may be too shallow or the patella is misaligned. There is a chance that dislocations can take place once in a while or very often. If the injury persists, then damage to the kneecap and the end of the thigh bone could arise.

What are the symptoms?

The symptoms associated with patellar instability vary because it solely depends on how much the patella has moved out of place and the extent of the damage done to the knee. Some of the more common symptoms include:

• Pain and swelling in the knee
• Pain when sitting
• Feeling a shift of the kneecap
• Creaking sounds upon movement of the knee
• Stiffness in the knee

How does Dr. Wingert address patellar instability?

Dr. Wingert will make the diagnosis by looking at you or your child’s medical history and then performing a physical exam. In some cases, an X-ray or MRI is obtained, depending on the severity of the dislocation. Based on the initial examination, Dr. Wingert can recommend non-surgical treatment, such as physical therapy or braces to immobilize the knee. In more serious cases, surgical treatment is recommended to restructure the ligaments that hold the patella in place. Our team in Kirkland will do everything possible to ensure the most precise diagnosis is made so that your knee can get back to its normal functions as quickly as possible.