Papers of the Week

Osteoarthritis (OA), a prevalent and disabling condition, significantly burdens individuals and healthcare systems worldwide. It is characterized by joint pain, stiffness, and structural changes in cartilage, bone, and synovium. The clinical manifestations of OA vary widely, reflecting complex interactions among genetic, metabolic, biomechanical, and environmental factors. Despite progress in identifying OA clinical phenotypes, inconsistent terminology, including “phenotypes,” “subtypes,” and “subgroups,” hinders effective communication and research translation. This review aims to synthesize existing literature on clinical OA phenotypes, terminology, and definitions and propose a research agenda.