Periosteal reaction
（重定向自Primary hypertrophic osteoarthropathy）
![Examples of periosteal reactive bone in selected specimens of Triceratops](/Images/godic/202502/04/Triceratops_lesions4210.jpg")
A periosteal reaction is the formation of new bone in response to injury or other stimuli of the periosteum surrounding the bone. It is most often identified on X-ray films of the bones.