In a grade 1 or 2 sprain, ligaments may heal on their own, but it is important in grade 1 or 2 to get it checked out by a physical therapist. A grade 3 injury to a ligament would be where the ligament has torn in half or detached and there is a complete separation from the ligament to the bone. In the case of a grade 3, surgery may be warranted; however, physical therapy will still be needed after and maybe even before surgery in order to heal the affected area properly.