Osteitis deformans is a chronic progressive bone disease characterized by the coexistence of local bone tissue osteoclasts and osteogenesis, bone absorption and reconstruction, osteoporosis and calcification. The disease is a chronic focal bone remodeling abnormality of unknown cause. Initially, bone absorption increases at the lesion site, followed by an increase in compensatory new bone formation, which causes the woven bone and lamellar bone at the lesion site to be inlaid, leading to disordered bone structure, bone enlargement and thickening, bone fragility, and increased intraosseous blood vessels at the lesion site. Clinical manifestations include bone pain, bone deformity and fracture. The disease does not directly invade the joints, but bone deformity can cause secondary joint lesions.