After craniotomy, the healing of the skull is not true bony healing, but rather fibrous connective tissue healing. If the patient has had general craniotomy surgery, including cranial hematoma removal and craniotomy tumor removal, the skull bone flap that was cut during the surgery needs to be returned to its original position. Such a cranial bone flap can still be fused to the body. However, the way it is fused is different from the way the human long bones are fused. This is because long bone fractures in the human body heal with a bone scab. The osteogenesis of long bones is itself epiphyseal osteogenesis. But the osteogenesis of the skull is not epiphyseal osteogenesis, but membranous osteogenesis. So the way the skull bone flap heals is fibrous connective tissue healing, not scab healing, bony healing.