A depressed fracture is a type of flat bone fracture, for example, the skull is a flat bone, and when it is struck by an external force, such as the inner and outer plates of the bone break and are depressed inward, either in one part of the fracture or in two parts of the fracture are depressed inward, which is called a depressed fracture. A depression fracture is a common form of fracture displacement in flat bone fractures, similar to scapula and pelvic bones. Sunken fractures that are minor and not much displaced are stable fractures. Larger displaced fractures can injure the brain tissue inside the skull, causing concussion, cerebral contusion, and secondary intracranial hematoma, which are more serious fractures. Minor fractures can be left undisplaced, while serious ones require craniotomy and surgery to make the depression flat before the pressure on the brain tissue can be relieved.