liigesopinnade

Liigesopinnad refer to the surfaces of bones that participate in joints. In synovial joints these surfaces are typically formed by the articular cartilage covering the opposing bone ends, with a subchondral bone base and a surrounding joint capsule and ligaments. The surfaces are adapted to allow smooth articulation, absorb loads, and distribute forces during movement.

Articular surfaces can be flat, curved, or complex in shape, affecting the range and direction of motion. The geometry of the surfaces, along with the joint capsule, ligaments, and surrounding musculature, determines stability and kinematics. Common examples include the ball-and-socket configuration of the hip and shoulder, the hinge-like motion of the elbow, and the more complex surfaces found in the knee.

Histologically, articular cartilage is a specialized hyaline cartilage that provides a low-friction, wear-resistant interface. It lacks a direct blood supply, getting nutrients from the synovial fluid. The subchondral bone under the cartilage supports the joint surface and undergoes adaptive remodeling with loading.

Clinical relevance centers on conditions that affect the integrity of liigesopinnad, most notably osteoarthritis, which involves degradation of articular cartilage and changes in the subchondral bone. Injuries can cause focal chondral defects, leading to pain and impaired function. Imaging techniques such as X-ray, MRI, or CT assess the condition of articular surfaces and surrounding structures.

See also: joint, articular cartilage, synovial fluid, osteoarthritis. The term liigesopinnad derives from languages where it denotes the surfaces of joints in contact during articulation.