Bone lines generally refer to epiphyses. Generally, the epiphyses cannot be reopened after they have closed. Normally, the epiphysis cannot be opened twice after it closes. The growth of the epiphysis is closely related to the age of the person, generally around 16~18 years old, the epiphysis will gradually begin to stop developing, that is, the epiphysis around the joints begin to close, when the epiphysis completely closed, the bone begins to stop growing, after the epiphysis closes the epiphysis also disappears, the local epiphyseal cartilage is also disappeared. However, there are some special cases, such as injury or fracture near the epiphysis caused by localized epiphyseal closure. In this case, the linear epiphysis is closed, and generally, the bone bridge can be opened through surgical means with a grinding drill, so as to restore the epiphysis to an open state. If you want to know whether the epiphysis is closed or not, you can go to the hospital for a bone age test. Generally, you need to do X-ray flat film of each bone of the finger and wrist, analyze it against the normal chart, calculate the bone age, and then see whether the epiphysis is closed or not.