Fig. 2.

Overview of OA stratification categories and their interactions. Clinical signs and symptoms, risk factors, and molecular signatures interact and can define OA subtypes. The combinatorial effects of different stratification measures will define distinct subtypes and stages of OA. For example, risk factors such as trauma will drive changes in molecular and cellular signatures and altered clinical signs and symptoms. As OA progresses stratification categories will continue to feedback on each other, therefore individual stratification measures (or combinations thereof) may be specific to a particular stage of disease