Patella Instability
What is a Patella Dislocation and MPFL Tear?
The knee joint consists of three bones: the femur (thigh bone), tibia (shin bone), and patella (kneecap). The patella sits in a groove at the end of the femur known as the trochlea, and is held in place by several ligaments and muscles. The most important of these is the MPFL, which attaches to the inner side of the patella and the inner side of the femur, preventing the patella from sliding outward.
Patella dislocation occurs when the kneecap (patella) moves out of its normal position, often towards the outside of the knee. This can result in a tear of the Medial Patellofemoral Ligament (MPFL), the primary ligament that stabilizes the patella and prevents it from dislocating. This injury disrupts the normal function of the knee and can lead to recurrent dislocations, chronic instability, and long-term damage to the knee joint.
Specializing in diagnosing and managing patella dislocation, Dr. Ben Mayo is a highly respected knee surgeon serving the Detroit area. He is known for his patient-centered approach and commitment to delivering top-tier care. Reach out to schedule your appointment at either his Livonia or Sterling Heights office and start your journey towards recovery.
Patella dislocations most commonly occur as a result of a sudden change in direction with the foot planted, like when pivoting in sports. They can also occur from direct trauma to the knee. An MPFL tear is usually the result of a patella dislocation. Some individuals are more prone to patella dislocations due to their anatomy, such as having a shallow trochlear groove, patella alta (a high-riding patella), or an increased Q angle (the angle between the quadriceps muscle and the patellar tendon).
A patella dislocation typically causes immediate severe knee pain and is visibly noticeable as the kneecap shifts out of place. Other symptoms include:
- Swelling and tenderness around the knee
- Difficulty walking or bearing weight on the knee
- A feeling of instability or the knee giving way
- Loss of range of motion in the knee
If left untreated, repeated patella dislocations can occur, leading to chronic knee instability and potentially to early-onset arthritis.
The diagnosis is typically made through a combination of patient history, physical examination, and imaging studies. The physical examination will assess for signs of patellar instability, and x-rays are used to confirm the diagnosis and rule out any fractures. An MRI is often useful to visualize the soft tissues of the knee, including the MPFL and the cartilage on the back of the patella.
Patella dislocations can be categorized into two types:
- Acute: This is a single, often traumatic event that results in the dislocation of the patella. It is frequently accompanied by an MPFL tear.
- Recurrent: This refers to repeated episodes of patellar dislocation. This usually occurs when the underlying factors causing the instability are not addressed.
While the pain and swelling from an acute patellar dislocation often improve with time and conservative treatment, the underlying instability may persist, particularly if the MPFL is torn. Non-surgical treatments like physical therapy can help strengthen the muscles around the knee and improve patellar tracking, which may help prevent future dislocations. However, recurrent dislocations or persistent instability may require surgical intervention.
Schedule a knee consultation
For advanced and individualized care for patella dislocations, trust in the expertise of Dr. Ben Mayo. As a fellowship-trained knee surgeon, Dr. Mayo is committed to providing you with the most effective and up-to-date treatment plans for MPFL tears. His clinics in Livonia and Sterling Heights cater to the Detroit area, including communities such as Troy, Canton, Macomb, Farmington Hills, Novi, and Royal Oak. Contact his office today to schedule a consultation.
At a Glance
Ben Mayo, MD
- Fellowship Trained Sports Surgeon
- Specializes in Minimally Invasive Arthroscopic Shoulder, Elbow, Hip, & Knee Surgery
- Published over 50 peer-reviewed articles and 10 book chapters
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