Steroid-associated osteonecrosis: Epidemiology, pathophysiology, animal model, prevention, and potential treatments (an overview)

Xie, Xin-Hui; Wang, Xin-Luan; Yang, Hui-Lin; Zhao, De-Wei; Qin, Ling

Steroids are now the second most common cause of ON after trauma and the prevalence of ON varies between 3% and 38% [3] . Five to twenty-five percent of patients with Figure 1 Five stages of osteonecrosis (ON) from X-ray and magnetic resonance imaging (MRI) according to the Association Research Circulation Osseus (ARCO) staging system on the femoral head. At Stage I, there are no visible changes on X-ray but demonstrable on MRI. At Stage II, there are some radiographic changes in the femoral head, but the joint surface maintains its integrity. As the disease progresses, the surface of the femoral head begins to collapse and finally the integrity of the joint is destroyed (Stage III and Stage IV). atraumatic ON are a result of steroid administration and 5% of patients with a history of high-dose corticosteroid administration developed ON. In Hong Kong and the region, up to 20% ON incidence was reported following treatment of SLE patients, patients with organ transplantation, and SARS patients with steroids. The ON appearances on MRI in patients under steroid treatment were the same as those caused by other aetiologies or conditions. It was reported that at least one ON lesion was found in 31% (138/448) of SARS patients after steroid therapy from Beijing Jishuitan Hospital, China [6] .