A person who is certified to make or fit artificial limbs or other parts of the body.

An Orthotic and Prosthetic Services provider designs, fits, and supplies braces, artificial limbs, or supportive devices to improve mobility and function.
Services are provided by certified orthotists, prosthetists, or licensed pharmacists who meet required professional standards.

When my teenager was 10 years old, they had to have a leg amputated as a result of their disability. They have successfully used an artificial leg since that time. However, they have outgrown it, and it is causing severe pain. They need a new one to accommodate their growth.