Fig. 3.

Early ligamentous osteoarthritis (OA)-based disease of the knee joint. Magnetic resonance imaging of a 38-year-old female with knee pain and clinical diagnosis of osteoarthritis, showing bone oedema at the anterior cruciate ligament insertion (asterisk). There is also meniscus extrusion (arrow) and peri-meniscal and high signal within and adjacent to the medial collateral ligament (arrowhead). Note that the articular cartilage is relatively normal. These changes point towards an OA disease process that evolves from the ligament.