What is the Origin of Subchondral Bone?

The term is descriptive, combining the Latin prefix sub (under) and chondral, referring to cartilage. Its anatomical and physiological importance has been increasingly recognized in orthopedics and rheumatology as a key player, rather than a passive structure, in joint health and disease. Understanding this structure is vital for addressing musculoskeletal and mobility concerns.

What is the Mechanism of Subchondral Bone?

The subchondral bone and articular cartilage form a functional unit, communicating through the diffusion of nutrients and signaling molecules across the calcified cartilage layer. Under normal loading, the subchondral bone undergoes continuous remodeling mediated by osteoblasts and osteoclasts. In pathological states, such as early osteoarthritis, increased bone turnover and microdamage in the subchondral bone can alter its mechanical properties, leading to stiffening or sclerosis. These changes disrupt the mechanical environment of the overlying cartilage, contributing to its subsequent degeneration and joint failure.

Subchondral Bone

Meaning

The layer of bone tissue located immediately beneath the articular cartilage within a joint, forming the foundation of the joint surface. This specialized bone is crucial for supporting the overlying cartilage, absorbing mechanical shock, and contributing to joint biomechanics. The health of the subchondral bone is intrinsically linked to the integrity of the cartilage, with communication between the two tissues being essential for maintaining joint homeostasis. Pathological changes in this bone are a defining feature in the progression of osteoarthritis and other degenerative joint diseases.