An extremity X-ray is a picture of your hand, wrist, arm, foot, ankle, knee, hip, or leg. It is done to see whether a bone has been fractured or a joint dislocated. It is also used to check for an injury or damage from conditions such as an infection, arthritis, bone growths (tumors), or other bone diseases, such as osteoporosis.
Why It Is Done
Extremity X-rays are done to:
- Find the cause of pain in an extremity.
- See if your bone is fractured or your joint is dislocated.
- See if fluid has built up in the joint or around a bone.
- See if your bones are positioned properly after treatment for a fracture or dislocation, such as after placing a cast or splint on an arm or leg. An X-ray also may be done after a doctor places a device such as a pin or an artificial joint in a bone.
- Find changes in your bones caused by conditions such as an infection, arthritis, bone growths (tumors), osteoarthritis of the hip, osteoarthritis of the knee, or other bone diseases.
- Find foreign objects such as pieces of glass or metal.
- Check to see if a child's bones are growing normally.
- See if your bones and joints are in the correct position after joint replacement surgery.
How To Prepare
In general, there's nothing you have to do before this test, unless your doctor tells you to.
How It Is Done
You will need to remove any jewelry that may be in the way of the X-ray picture. You may need to take off some of your clothes, depending on which area is examined. You will be given a cloth or paper gown to use during the test. You may be allowed to keep on your underwear if it does not get in the way of the test.
During the test
During the X-ray test, you will sit by or be on an X-ray table. The X-ray technologist will position your limb. If you have an injury, your leg or arm will be handled gently and supported when moved or repositioned. Pillows, sandbags, or other objects may be used to hold the injured limb in place while the pictures are taken. If you are wearing a brace or other device, it may need to be removed. A lead shield may be placed over your pelvic area to protect it from radiation.
Two or more pictures of the affected limb are usually taken. X-ray pictures may also be taken of other joints or limbs, since an injury at one point may cause damage somewhere else. Sometimes an X-ray picture of the unaffected limb is taken so it can be compared with the affected limb.
How long the test takes
An extremity X-ray usually takes about 5 to 10 minutes. You will wait about 5 minutes until the X-rays are processed, in case repeat pictures need to be taken. In some clinics and hospitals, X-ray pictures can be shown right away on a computer screen (digitally).
How It Feels
You won't feel any pain from the X-ray itself. You may find that the positions you need to hold are uncomfortable or painful. This is more likely if you have an injury.
There is always a slight chance of damage to cells or tissue from radiation, including the low levels of radiation used for this test. But the chance of damage from the X-rays is extremely low. It is not a reason to avoid the test.
If you need an X-ray during pregnancy, a lead apron will be placed over your belly to protect the baby from exposure to radiation from the X-rays. The chance of harm is usually very low compared with the benefits of the test.
In an emergency, the doctor can see the initial results of an extremity X-ray in a few minutes. Otherwise, a radiologist usually has the official X-ray report ready the next day.
The bones, joints, and soft tissue look normal. No foreign objects, such as fragments of metal or glass, are present.
No infection and no abnormal growths (tumors) are present.
The joints are normal with no dislocation or signs of disease, such as arthritis.
All parts of a joint replacement are in the correct position.
Fractured bones may be present.
Foreign objects, such as fragments of metal or glass, may be present.
Abnormal growths (tumors) are present.
Signs of bleeding or infection, such as a collection of blood, pus, or gas may be present.
A joint may be dislocated.
Swelling is present in tissues around the bones even though the bones may be normal.
There are loose parts, worn parts, or an infection in a joint that has artificial pieces (joint replacement).