Adapted from Radiopaedia.org
Did you know that your kid’s wrist x-ray roughly matches his/her age?
The small bones of the wrist are called the carpal bones. They start out with no calcium at birth, and do not show on x-ray. They start building up calcium during the first three months of age in a process called Ossification. This occurs in a predictable manner and the bones ‘start appearing’ on x-ray in this order:
- One bone: 1-3 months
- Two bones: 2-4 months
- Three bones: 2-3 years
- Four bones: 2-4 years
- Five-seven bones: 4-6 years
- Eight bones: 8-12 years
Next time you get an x-ray of your child’s wrist, count the ‘little round’ bones to find out the ‘bone age’.
Time to ossification, similar to height and weight of a growing child, can be highly variable and bone age X-rays are not obtained for healthy children. A discrepancy between bone age and actual age is not a reason to worry unless there are concerns about the child’s growth.