Growth/Bone Age

Is bone age fusion a universal thing? I am 17, I've only had one growth spurt, and recently scheduled an appointment to see an endocrinologist. Before my appointment I got an x-ray taken of my hand, and the radiologist said it is around an 18 year old's bone age. He did not write in his review that the bones were fused or not though. I know some boys grow up until their 20's, but I've read that's because their bone age is immature. Most of the men in my family had their last big growth spurt in early college late high school. Can one person's bone age fuse over at 18, and another persons bone age fuse over at 21? (I accidentally posted this in teen health before I saw this forum, so I hope this isn't considered spam.)

[S. Kaul, MD]

Hi there!

Yes, bone age is a universal thing, but normally for describing bone age we use a range like 16-18 years or 18-20 years and its not that all bones fuse at 18 years. Bone maturation and fusion is a gradual process that begins before birth and continues to ones 20’s. However specific bones would have a range of 1-2 years when they are expected to fuse and deviation from this is considered abnormal; which could occur due to a number of secondary reasons. For this reason a bone age of 18 at 17 years of age would not be abnormal, though a bone that is expected to fuse at 18 but actually fuses at 21 is abnormal. Aside bone growth, the total growth is dependent on a number of other factors as well and growth may continue beyond a pubertal growth spurt, though this tends to be slower.
Hope this was helpful.

Take care!

[S. Kaul, MD]

Hi there!

Yes, bone age is a universal thing, but normally for describing bone age we use a range like 16-18 years or 18-20 years and its not that all bones fuse at 18 years. Bone maturation and fusion is a gradual process that begins before birth and continues to ones 20’s. However specific bones would have a range of 1-2 years when they are expected to fuse and deviation from this is considered abnormal; which could occur due to a number of secondary reasons. For this reason a bone age of 18 at 17 years of age would not be abnormal, though a bone that is expected to fuse at 18 but actually fuses at 21 is abnormal. Aside bone growth, the total growth is dependent on a number of other factors as well and growth may continue beyond a pubertal growth spurt, though this tends to be slower.
Hope this was helpful.

Take care!