Subchondrale

Subchondrale refers to the region of bone directly beneath the articular cartilage in a synovial joint. The subchondral compartment comprises the subchondral bone plate (dense cortical bone) and the underlying subarticular cancellous or trabecular bone. Together they support the cartilage, help transmit load from the joint surface to the deeper skeleton, and contribute to the joint’s overall mechanical resilience.

In health, subchondral bone adapts to mechanical stress through remodeling, maintaining a balance between bone formation and resorption. Under abnormal or repetitive loading, this adaptation can become dysregulated. In osteoarthritis, for example, the subchondral plate often undergoes sclerosis (increased density) and structural changes, while the underlying trabecular bone remodels. These changes can be accompanied by bone marrow lesions, cyst formation within the subchondral region, and a reduced capacity to absorb impact, which may contribute to further cartilage degeneration and pain.

Pathologic conditions affecting the subchondral bone include subchondral insufficiency fractures, which occur when weakened bone cannot tolerate normal loads, typically in elderly or osteoporotic patients. Imaging findings in the subchondral zone are used to assess disease activity and structural integrity: radiographs may show sclerosis or collapse of the subchondral plate; MRI can reveal bone marrow edema, subchondral cysts, and fracture lines; CT offers detailed visualization of cortical sclerosis and trabecular architecture.

Terminology varies by language; the form subchondrale is common in Romance-language contexts, while in English the adjective is typically subchondral.