Liigesepinda

Liigesepinda is the term used to describe the joint surface of a bone that participates in articulation with another bone within a synovial or other type of joint. It refers to the area that comes into contact during movement and load transfer, and is typically covered by articular cartilage to facilitate smooth motion.

Anatomy and composition: The joint surface is usually lined with articular cartilage, often hyaline cartilage, which provides a low-friction interface. Beneath the cartilage lies subchondral bone, and the surface is bordered by a joint capsule and supporting ligaments that guide motion and provide stability. In many joints, the surface curvature—being convex, concave, or planar—contributes to the joint’s range of motion and mechanical stability.

Variation among joints: Different joints exhibit distinct articular surfaces. For example, ball-and-socket joints feature a rounded convex surface fitting into a concave socket, enabling multi-axial movement; hinge joints present reciprocally curved surfaces that allow mainly flexion and extension. Some joints have more complex or irregular surfaces to accommodate specific patterns of movement and load distribution. The integrity and congruence of these surfaces are crucial for balanced biomechanics.

Function and clinical relevance: The liigesepinda enables articulation while distributing mechanical loads, reducing friction, and absorbing shocks through lubrication by synovial fluid. Degenerative changes, such as cartilage wear or fissures, can roughen the surface, leading to pain and impaired function. Imaging and histological assessment of the articular surface are important in diagnosing joint diseases.

Etymology and usage: In Estonian, liigesepind literally means joint surface and is used in anatomical descriptions. In English, the equivalent term is articular surface.