Table 1.

Summary of the clinical, pathophysiologic, biochemical and biomechanical changes that characterize OA. Table contents extracted from text definition of OA by Flores et al⁵.

Changes	Characteristics
Clinical	Joint pain, tenderness, limitation of movement, crepitus, occasional effusion, swelling, and local (but not systemic) inflammation
Pathological	Irregularly distributed loss of cartilage more frequently in areas of increased load, sclerosis of subchondral bone, subchondral cyst, marginal osteophytes, increased metaphyseal blood flow, and variable synovial inflammation
Histological	Early fragmentation of the cartilage surface, cloning of chondrocytes, vertical cleft in cartilage, variable crystal deposition, remodeling and eventual violation of tidemark by blood vessels
Biochemical	Reduction in the proteoglycan concentration, alteration in collagen fibril size and weave, and increased synthesis and degradation of matrix macromolecules
Biomechanical	Alterations of the tensile, compressive, shear proprieties, and hydraulic permeability of the cartilage. Increased stiffness of the subchondral bone.