Tfcc injured. Will immobilization of the wrist heal cartilage?

Varies. It varies quite a bit, depending in part on the severity of the injury to the TFCC. Some people may have a very mild injury and do fine without even immobilization, while others can have injuries severe enough they need surgery. Initial immobilization is appropriate for many TFCC injuries to see if they will heal. May want to discuss specifics if your injury with your MD.