Nivelpää

Nivelpää is the Finnish term for the articular head of a bone—the rounded end that forms a joint surface with another bone in a synovial joint. In typical usage it refers to the prominent, ball-like end that allows smooth articulation, such as the femoral head in the hip joint or the humeral head in the shoulder joint. The term can also apply to other joints where a rounded bone end participates in articulation, such as the radial head at the elbow.

Anatomically, the nivelpää is covered with articular cartilage and is often connected to the shaft by a neck or narrow region. The articular surface interacts with a corresponding socket or planar surface on the partner bone, enabling movement within the joint’s range. Blood supply to the subchondral bone beneath the cartilage is important for growth, repair, and health of the joint surface.

Developmentally, nivelpää originates from the bone’s epiphysis, with growth occurring at the growth plate during development. In adulthood the epiphysis generally fuses with the diaphysis, and the head becomes a fixed part of the bone.

Clinical relevance centers on injuries and diseases affecting the joint surface or its blood supply. Fractures or dislocations involving the nivelpää can impair joint function and may predispose to avascular necrosis or osteoarthritis. Understanding the anatomy of the nivelpää aids in diagnosing joint disorders and planning surgical or rehabilitative treatment.

See also: epiphysis, articular cartilage, synovial joint, joint capsule.