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

The cartilage layer could be found detached from the bone in severe ON under MRI or arthroscopic evaluation. Glucocorticoid receptors were present in cartilage and the steroid was revealed to cause cartilage disruption with acellular areas [20] , which indicate that the steroid might result in the degeneration of articular cartilage. In most patients, subchondral collapse changes the articular surface, leading to abnormal mechanics (e.g., local stress concentration) that is believed to be associated with development of arthritis to the joint [21] . Our study revealed that the thickness of the subchondral plate of SAON emus decreased significantly and the articular cartilage showed pathological alteration with significantly decreased thickness as well as the decreased proteoglycans content located at the collapsed region [22] . Following subchondral collapse, the cartilage components might be exposed to the ongoing repair process. Cartilage constituents may thus promote the development and continuance of the disease process in ON and explain the localisation of ON to subchondral bone [23] .