How do growth plates help long bones increase in length?

Growth plates, also known as epiphyseal plates, are responsible for the longitudinal growth of long bones through a process of endochondral ossification.12

This mechanism involves a continuous cycle of cartilage production and replacement:

• Cartilage Proliferation: Within the growth plate, specialized cartilage cells called chondrocytes undergo rapid division and growth.12
• Replacement by Bone: On the side of the plate facing the bony shaft, these cartilage cells degenerate and calcify. They are then replaced by new bone tissue.12
• Maintenance of Thickness: The rate at which new cartilage is produced by the growth plate is closely matched by the rate at which it is replaced by bone. This allows the plate to maintain a relatively constant thickness while the bone shaft itself increases in length.12

This process is stimulated by hormones, particularly growth hormone and insulin-like growth factor. Longitudinal growth continues until skeletal maturity, at which point the growth plates fuse and disappear, preventing further lengthening of the bone.312