What is the patella?
The patella, or kneecap, is located in front of the femur (thigh bone) and tibia (large lower leg bone). When the knee moves, the patella slides within a groove on the femur. Cartilage lines the undersurface of the patella. The anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL) are the two major ligaments of the knee joint. The patella’s most important role is extension of the knee. It is attached to the tendon of the quadriceps muscle, which contracts to extend or straighten the knee.
What is a patella fracture?
A patella fracture is a fracture of the kneecap, the triangular bone in front of the knee joint. The most common patella fractures are caused by a fall onto the knee or when the knee strikes the dashboard of a car in a traffic accident. Patella fractures can also result when the quadriceps muscle suddenly contracts. This is a common injury in men between 20 and 50 years of age.
What are the signs and symptoms of a patella fracture?
Signs of a patella fracture include intense pain, swelling of the knee, and the inability to bend the injured knee. The patient is often unable to walk. In hairline fractures, swelling may be absent and tenderness over the kneecap may be the only symptom.
The most common patella fractures are caused by a fall onto the knee or when the knee strikes the dashboard of a car in a traffic accident. Patella fractures can also result when the quadriceps muscle suddenly contracts. This is a common injury in men between 20 and 50 years of age.
How is a patella fracture diagnosed?
X-rays of the knee joint reveal the type and severity of the fracture. The doctor will test whether the patient is able to perform a straight leg raise. An MRI can detect abnormalities that may not be observed in x-rays.
Patella fractures fall into several types, including transverse and longitudinal fractures, comminuted fractures (the patella is broken into several pieces), and osteochondral fractures when cartilage is also injured.
How is a patella fracture treated?
If the patella fracture is undisplaced and the patient is able to perform a straight leg raise, the fracture can be treated with a plaster cast.
If surgery is necessary, the doctor restores the kneecap to its original alignment using a combination of screws, pins, and tensioned wires. In cases where the patella is fractured into several pieces, as in comminuted fractures, part of the kneecap may be removed. When damage is so severe that returning the kneecap to its original position is impossible, complete removal of the patella may be required.
Recovery time depends on the method of treatment used to repair the patella fracture. Some patients are able to change out of a plaster cast to a knee brace in as little as two or three weeks. If there is no pain six weeks after surgery, the patient can begin gentle range of motion exercises. Once strength and range of motion have been restored, the patient increases supervised exercise to restore full movement. Pool running and water exercises are beneficial.
Will I have knee pain after the fracture is healed?
Knee pain after a patella fracture is common, even after healing. Using a knee brace helps to lessen knee pain.
What can I do to prevent osteoarthritis?
Strengthening the quadriceps can help prevent osteoarthritis.
How can I protect my knees while playing sports?
Protective kneepads are especially helpful for skateboarders, handball players, and hockey players.