What do doctors look for in x-rays of long bones to determine if a teenager is done growing?

X-ray findings that indicate a teenager is done growing:

1. Growth plate closure: The growth plate is a cartilaginous region at the end of long bones where growth occurs. When a teenager is done growing, the growth plate fuses and becomes a solid bone. This can be seen on an x-ray as a horizontal line across the end of the bone.

2. Bone density: As teenagers grow, their bones become denser. This can be seen on an x-ray as a gradual increase in the whiteness of the bones.

3. Shape of the bone ends: The ends of long bones are typically round in children and adolescents. As teenagers approach the end of growth, the bone ends become more square-shaped.

4. Apposition of the secondary ossification centers: In long bones, there are secondary ossification centers that appear at specific ages during childhood. When these centers fuse with the main part of the bone, it is a sign that growth is complete.

5. Epiphyseal fusion: During adolescence, the growth plate (physis) is responsible for the elongation of long bones. It fuses (epiphyseal closure) when growth ceases.

It's important to note that these are general guidelines and the assessment of skeletal maturity can be complex, especially in cases where there are variations in growth patterns or underlying medical conditions. A doctor will consider multiple factors, including the individual's age, medical history, and other relevant information, to determine whether a teenager is done growing.