Treating the most common of wrist fractures
Ask the GP...
Our GP on wrist fractures and why it is necessary to have a cast.
Question: My son fell and hurt his wrist. We went to the hospital. At first we were told there was no break, but then he was given a cast and told he had to come back in two weeks. Why does he need a cast?
Dr Nina replies: The wrist is made up of eight small bones. The scaphoid bone is a boat- shaped bone located on the same side as your thumb.
Scaphoid fractures (breaks) are the most common fracture of the wrist bones. They occur mainly when a person falls on to an outstretched hand where the palm lands flat and the hand is bent back.
The scaphoid is an important bone in the wrist helping to support the structures around it. Scaphoid fractures are not always easy to diagnose. The degree of pain may vary and many often mistake the discomfort for a sprain. Swelling and bruising may or may not occur. A visit to your doctor can be helpful.
Scaphoid fractures are often very tender when pressure is placed on a specific triangle near the base of the wrist below the thumb. This is called your anatomical snuffbox.
About 10-20pc of scaphoid fractures don't show on an initial X-ray, so if a doctor has a high suspicion in view of the injury that occurred, they will likely place a cast and repeat the X-rays 10 days to two weeks later, as this is when the fracture is more likely to show.
Occasionally, a CT scan or MRI might be required to confirm a scaphoid injury.
It is important not to miss a scaphoid fracture as poor healing can result in complications.
The blood supply to the scaphoid bone enters it largely from one end. If the bone breaks, and isn't immobilised or brought together, the part that is separated from its blood supply can die or break up. This process is called avascular necrosis - this may lead to pain occurring some time after the fracture or ultimately, arthritis of the wrist joint.
If a fracture occurs in the bone, but it has not moved, then treatment is usually just with a cast. This may need to remain in place for six to 12 weeks.
Regular reviews and X-rays are required to ensure the bone is healing and joining again.
In a more serious fracture, the bone may move out of line. This may require surgery and placement of a screw or pin to bring the bone back into place. Immobilising is then also required.
Due to the fact that missed scaphoid fractures can lead to long-term problems and discomfort, doctors will err on the side of caution placing a cast and reviewing 10 days to two weeks later.
It sounds like your son is being well cared for.
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