Patella Fracture

A break in the kneecap is known as a fracture of the patella. A fall from a height, a direct blow to the knee and indirect stress are some of the frequent causes of patella fractures. Severe pain, swelling, tenderness and difficulty in straightening the knee are some of the common symptoms associated with patella fracture. Fracture of the patella is also known as kneecap fracture, broken knee, knee fracture and broken patella.

Causes of a Patella Fracture

• Direct force on the patella can result in fracturing the patella.
  
• A fall from a height or a hit to the knee which is very common in contact sports.
  
• During an automobile accident, when a knee that is bent hits against the dashboard and can lead to a patella fracture.
  
• Indirect stress is one reason that can cause patella fracture.
  
• Twisting of the leg.
  
• Muscle contraction that is violent.
  
• Calcium deficiency due to poor nutrition.
  
• Persons who are obese are more prone to this kind of fracture if they suffer a fall.
  
• Joint diseases such as osteoporosis or bone diseases increase the risk of fracture of this kind.

Severe pain and swelling at the area of the fracture is noticed when a person fractures his patella. It will be difficult to move the leg either forward or backward or extend it. There may be swelling and tenderness around the kneecap along with catching or locking of the knee. If bone fragments split enough to bend or twist normal knee contours, deformity of the knee will be apparent. The patient may experience numbness and chill that extends beyond the site of the fracture, if the blood supply at the site gets affected. In a compound fracture or open fracture, the skin is broken by the bone in extreme cases. Immediate attention should be given to this open fracture to avoid infection. The fracture of the patella is classified into three different types.

• As a result of a direct blow an undisplaced fracture of the patella may occur
  
• A direct blow to the front of the knee or a fall can cause a stellate or comminuted fracture. Compromised anterior skin and subcutaneous tissue may be associated with this type of fracture which may be the result of a direct trauma.
  
• The third type is a transverse fracture where there is a gap between the fragments. There is possibility for this fracture when there is a forced, passive flexion of the knee joint is associated with a contraction of the knee joint extenders or the quadriceps muscles.
  

There should not be any delay in realigning the broken bones to reduce the shock. To determine if the patient has suffered a fracture the physician will request for x-rays and stress films after he examines the knee. To immobilize the fracture site, the physician may realign the broken bones and place the knee in a cast or splint only if the fragments of bones are lined up well. Surgery is the other option to remove broken pieces of the knee. A person who has suffered a patella fracture is more prone to knee problems in the future.

Bone density test

Special x-rays are used to determine how many grams of bone mineral content (calcium and other bone minerals) is filled into a section of the bone. Bones with high mineral content indicate very dense bones thus indicating the bones are strong and have fewer chances of breakage. Bone density tests are recommended by doctors to check for osteoporosis. Bone density tests are done either by central or peripheral devices. Central devices are huge machines on which the patient can lie down. Such devices are mainly used to check the lumbar vertebrae (lower region of the spine), the narrow neck of the femur bone adjoining the hip and the bones of the wrist and the forearm.

Dual energy X-ray absorptiometry (DXA): This test produces exact results and is the most preferred choice to diagnose osteoporosis. The patient will be asked to lie down on a padded platform as an imager (an apparatus like a mechanical arm) passes above the body. The required information is captured by the device and the test is completed within 20 minutes. The amount of radiation exposure in this test is equal to one-tenth of a chest x-ray radiation. DXA scan can detect even a 1% change in the bone, that which can not be achieved through an ordinary x-ray.

Quantitative CT scan: The bone density (especially spine) is measured with the help of a computerized tomography (CT) scanner along with computer software. The scan produces a three-dimensional picture which also relates to the aging consequences of the bone and diseases other than osteoporosis. The patient is made to lie down on a movable table that is directed into a big tube-like area where images are pictured. The test is completed within 20 minutes and the radiation exposure is slightly more when compared to the DXA scan.

Peripheral devices are moveable machines that measure the bone density on the periphery of the skeleton. e.g. finger, wrist or heel. They are smaller machines when compared to the central devices and can be found in pharmacies and have their own restrictions. These machines are used to check for the bone density in the heel, or wrist or fingers.