costosternale

Costosternale, or costosternal, is an anatomical term referring to structures and joints between the sternum and the costal cartilages of the ribs. The sternum, or breastbone, is formed by the manubrium, the body, and the xiphoid process, and ribs 1–7 connect to it via costal cartilage. The term most often concerns the sternocostal joints, which link the costal cartilages to the sternum.

The first sternocostal joint, between the first costal cartilage and the manubrium, is typically a synchondrosis (a primary cartilaginous joint) that tends to ossify with age. Joints between the cartilages of ribs 2 through 7 and the sternum are plane synovial joints, allowing small gliding movements. These joints are reinforced by capsule ligaments and by surrounding sternocostal ligaments and intercostal muscles, contributing to the stability and elasticity of the anterior chest wall.

Functionally, the costosternal connections enable the rib cage to expand and contract modestly during respiration, aiding ventilation while maintaining chest wall integrity. They also contribute to the structural linkage that supports upper body movements and protects thoracic organs.

Clinical relevance includes various causes of pain or dysfunction in the costosternal region, such as inflammation or trauma to the sternocostal joints, costochondritis, Tietze syndrome, or degenerative changes with aging. Accurate assessment is important in chest pain syndromes to distinguish costosternal issues from cardiac etiologies.