Patella Fractures

The patella is a small triangular bone located at the front of the knee. It is embedded in a tendon and sits in a groove on the thighbone (the femur) and slides up and down and helps the leg muscles bend and straighten the knee. Tough ligaments attach the patella at the top to the quadriceps muscles and at the bottom to the shinbone and hold the patella in its groove. The patella serves an important function in stabilizing the knee and protecting the joint from injuries.

The patella is the most commonly broken bone in the knee.  Patellar fractures are more common in men, accounting for about 1% of all fractures. Open injuries account for 6% – 9% of patellar fractures and are associated with other injuries.

What causes a patella fracture?

A patellar fracture is usually caused by high energy trauma such as a fall or auto accident. A patellar fracture may also be accompanied by fracture of the ends of the tibia or femur. It can also fracture from a sudden contraction of the quadriceps muscle. Simple fractures can be treated with a cast, but complex fractures may require surgery to restore and stabilize the kneecap.

What are the types of patellar fractures?

The patella can fracture multiple directions, in a single direction or shatter into multiple pieces. It can break at the top, middle or bottom. It may be a stable fracture, meaning the broken pieces are in alignment and remain in the correct position for healing.  However, a displaced fracture means the bone ends don’t meet up and will require surgery to realign the pieces so they can heal together. The fracture may be open, pieces of bone break through the skin and damage soft tissues.

What are the symptoms of a patellar fracture?

A patellar fracture is a serious injury that can make it impossible to walk. Pain, swelling, and bruising are the most common symptoms of a patellar fracture. You may have difficulty bending or straightening the knee. In some cases, the kneecap may be visibly out of place.

How is a patellar fracture diagnosed?

Your Providence Center for Orthopedic Specialists clinician will review your medical history, ask how you injured your knee, and perform a physical exam including special tests to see if you can bend or straighten the knee. They will also check to see if there is a lot of bleeding in the joint that can cause painful swelling. They will order x-rays to evaluate the fracture and see the fracture pattern. In some cases, an MRI or CT scan may be ordered to evaluate damage to the soft tissues. With this information they will render a diagnosis and discuss treatment options.

What are the treatment options for a patellar fracture?

Nonoperative treatment is an option when the break is minimally displaced, and the quadriceps muscle and tendon, and patellar ligaments are intact. Most patellar fractures are painful and require pain management from over-the-counter pain medications and sometimes prescription pain medications.

Treatments options for patellar fractures depend on the severity of the injury. Sometimes the break can be treated without surgery if the pieces are properly aligned. In this case, treatment may simply involve immobilization of the knee in a cast or splint for six to eight weeks.

When the pieces of bone are out of alignment, surgery will be necessary to realign and stabilize the bones. In some cases, metal plates, screws, or rods may be used to hold the bones in place.

Physical therapy is essential to restore function and mobility in the knee. Most patients can return to the activities of daily living within 3-6 months. One important consequence of a patellar fracture is the risk of posttraumatic arthritis.

Contact Providence Center for Orthopaedic Specialists at one of our locations, Mission Hills, Tarzana, West Hills, and Westlake Village to schedule a consultation to find out if you are a candidate for shoulder surgery. You will always be treated with respect and compassion.