If a simple ulnar fracture is treated properly, the forearm or hand function can be restored to a good state, and the level of disability will not be very high. If the fracture is not significantly displaced and can be treated by splinting or external fixation in a cast, it can be evaluated at grade 11 or 12. If the fracture is more serious, displaced, or even open fracture, it needs surgery or surgical incision and internal fixation with plate or interlocking intramedullary nail, then it can be evaluated to grade 10.