This injury happens when there is a break in the patella. The patella is a large, movable bone at the front of the knee.

The Kneecap

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The patella is part of the knee joint. It is formed between the tendons that connect the thigh bone (femur) to the leg bone (tibia). It protects the front of the knee joint and acts as a point of support, providing increased power to the thigh muscles, which extend the knee. The inner portion of the patella does come in contact with the thigh bone part of the knee joint.

Some common causes of this injury include:

  • Sharp blow to the knee (eg, during sports, a fall, or a car accident)
  • Excessive stress on the knee (eg, during weight lifting, stair climbing, or overexercising a healing knee)

Risk Factors

These factors increase your chance of developing a patella fracture:

  • Advanced age
  • Postmenopause
  • Decreased muscle mass
  • Osteoporosis (decreased bone mass)
  • Participation in contact sports (eg, football, soccer)
  • Obesity , which places strain on muscles, bones, tendons, and ligaments
  • Violence, such as car or car-pedestrian accidents

Tell your doctor if you have any of these risk factors.


If you have any of these symptoms do not assume it is due to a patella fracture. These symptoms may be caused by other conditions. Tell your doctor if you have any of these:

  • Sudden, excruciating pain in the kneecap
  • Swelling and tenderness
  • Inability to extend the knee


Your doctor will ask about your symptoms and medical history. She will also do a physical exam. The doctor will look closely at the knee to see if there are signs of fracture . Tests may include:

  • Straight leg test—a test to see if you are able to raise your leg while lying flat; if you are unable to, this could be a sign of a fracture
  • X-ray —a test that uses radiation to take a picture of structures inside the body, especially bones, to look for a break in the bone
  • CT scan —a type of x-ray that uses a computer to make pictures of structures inside the body, shows more detailed imaging
  • MRI scan —a test that uses magnetic waves to make pictures of structures inside the body


Talk with your doctor about the best treatment plan for you. Treatment options include the following:

Nonsurgical Approach

After the tests, your doctor will determine whether you need surgery. If the patella is not badly injured, your doctor will place the knee in a cast . This cast may need to be worn for six weeks. After that, you will wear a knee brace and do physical therapy. You may need to use a cane or a crutch .

Your doctor may recommend pain medication to reduce pain and swelling.


If the patella is in pieces, then you will need surgery. There are two kinds of surgery that are commonly used to treat this injury:

  • Open reduction-internal fixation surgery—The doctor uses pins and screws to put the broken pieces back together.
  • Patellectomy—The doctor removes part of the kneecap or the entire kneecap.

After surgery, you will need to do physical therapy. This can involve range-of-motion exercises and stretching . You will slowly build strength in the injured leg. In some cases, another surgery will be needed to remove the pins and screws .

Depending on the injury, recovery can take weeks to several months.


To help reduce your chance of getting a patella fracture, take the following steps:

  • Do not put yourself at risk for trauma to the bone.
  • Eat a diet rich in calcium and vitamin D .
  • Do weight-bearing exercises to build strong bones.
  • Build strong muscles to prevent falls and to stay active and agile.
  • Wear proper padding and safety equipment when participating in sports or activities.