Patellar Dislocation Overview
Patellar dislocation, or kneecap dislocation, is caused by an unnatural twist or direct impact to the knee. When a dislocated patella occurs, it can cause extreme pain, stiffness and swelling in the affected knee. If surrounding ligaments are weak from tendonitis of the knee, the chances for a dislocation increase. Chicago, Westchester, Oak Brook and Hinsdale, Illinois area orthopedic knee specialist, Dr. Nikhil Verma specializes in treating various knee injuries, including a patellar dislocation.
A dislocated patella is quite common, especially in younger athletes. Athletes and active individuals typically experience this injury when the foot is planted and a rapid change of direction (twisting) occurs or when a sharp blow to the knee or fall occurs. However, in some patients, due to abnormalities in the underlying knee anatomy, dislocation can occur with relatively little force and may happen repeatedly. After a patient experiences a patellar dislocation, it is critical to relocate the kneecap back to its original position in the trochlear groove. This often occurs spontaneously as the patient extends the knee or manually by a sports medicine specialist in a medical setting.
Patellar dislocations normally cause associated knee conditions, such as tearing of the ligaments. “Loose bodies,” small fragments of articular cartilage that break off in the knee joint, can also cause locking, catching and additional cartilage damage.
Symptoms of a Patellar Dislocation
Symptoms of a dislocated patella are marked by rapid, acute swelling and severe knee pain until the kneecap is relocated to its original position. Other common symptoms include:
- Feeling that the knee may buckle or give away
- Hearing a popping sound at the time of dislocation
- Knee may appear deformed
Diagnosis of a Dislocated Patella
If the patella has slid back into place on its own, a patient should visit Dr. Verma as soon as possible. If the patella is still dislocated, an ER visit is critical. Once the kneecap is in place, Dr. Verma will perform a thorough medical history review and physical examination. He will determine if the injury was caused by a traumatic event, weakening of the ligaments from tendonitis of the knee or a combination of both. He will also use diagnostic tests, such as X-rays and an MRI scan, to evaluate loose bodies, cartilage and surrounding ligaments.