Disc herniation is rather rare in young children and teens. But it is not unheard of. Usually, any force (traumatic or repetitive) that’s enough to cause disc protrusion can also damage the apophyseal ring.
The ring is a tough, fibrous structure around the outer portion of the vertebral body next to the disc. It is attached to the outer portion of the disc called the anulus fibrosis. The ring apophysis attaches the anulus fibrosus to the vertebra. The ring provides an area of denser, stronger bone for the edge around the vertebral bone.
A fracture of the ring indicates that the fibrous ring (along with a small piece of bone still attached) has pulled away from the vertebra. This can occur along the upper (above) or lower (below) endplate of the affected disc. It appears to be caused more by repetitive stress rather than a single traumatic event. Many of the athletes who have a ring apophysis fracture don’t even know it.
The ring hardens into more of a bone-like substance around six years of age. By the end of puberty or around age 17, the apophysis fuses with the vertebral body. Until then, there is a weak point between the ring and the apophysis. A traction force on this area during movement of the spine can be strong enough to cause a disc herniation and an apophyseal ring fracture.