Human growth plates, or epiphyseal plates, normally close by the age of 17. The process generally happens between the ages 13 and 15 in females, and between the ages of 15 and 17 in males.
The human body has at least two growth plates on each long bone. The plates are made of developing tissue and are responsible for bone growth. When a person stops growing, the plates close and fuse together in a process called ossification. Bones with active growth plates are more susceptible to fractures, and injured plates can result in irregular growth and arthritis. When the growth plates ossify, they are replaced with an epiphyseal line.