Subchondral bone pathology (SBP) includes a wide range of pathologies, including trauma, postcartilage surgery, osteoarthritis, transient bone marrow syndromes, spontaneous insufficiency fractures, and osteonecrosis. They show joint MRI findings termed bone marrow lesions. However, the etiology and evolution of SBP in multiple conditions remain unclear. A key factor to address in a patient with BME is the distinction between reversible and irreversible lesions. MRI plays a significant role in the differential diagnosis based on recognizable typical patterns considered together with coexistent abnormalities, age, and clinical history. This article will focus on the current understanding of the biologics of SBP.