The sternoclavicular joint (from anatomical ( Latin ) articulatio sternoclavicularis , sternum-clavicle joint , also medial clavicle joint ) is the articulated connection between the breastbone ( sternum ) and the collarbone ( clavicle ). It lies at the neck end of the sternum and protrudes beyond its upper edge, which is why it is visible and palpable through the skin. It is the only bony connection between the upper extremity and the trunk.
The joint socket is formed by a shallow dimple in the “handle” of the sternum ( manubrium sterni ). The articular surfaces of the sternoclavicular joint are irregular, between them there is usually a complete cartilage disc ( discus articularis ), so that the joint is functionally a ball and socket joint . The collarbone can move in the frontal plane and in the transverse plane and rotate around its own axis. The stability of the joint is provided by several ligaments ( ligamentum sternoclaviculare anterius , ligamentum sternoclaviculare posterius , ligamentum interclaviculare and ligamentum costoclaviculare ).
The cartilaginous connection between the sternum and the first rib lies under the sternoclavicular joint . Behind the sternoclavicular joint is the front limit of the pleura and the venous angle (confluence of the internal jugular vein to the subclavian vein ), in the left and the thoracic duct , the right of the lymphatic duct open. Immediately behind the right sternoclavicular joint lies the branching of the brachiocephalic trunk into the subclavian artery and the common carotid artery .
Dislocations of the sternoclavicular joint are rare. With collarbone fractures , there is a typical displacement. Osteonecrosis of the medial end of the clavicle (Friedrich's disease) is very rare . Also, osteoarthritis occurs rarely, this then prepares for raising the arm above about 80 ° to the side pain, because then the clavicle rotates sternoclavicular joint. An endoprosthesis of the sternoclavicular joint has been described. More often, especially in younger women, there is painful swelling of the sternoclavicular joint and the adjacent rib-sternum junctions, combined with hyperostosis . This disease is one of the rheumatic forms around the SAPHO syndrome - with imprecise classification and numerous synonyms. Therapy is usually a nonsteroidal pain therapy , z. B. with diclofenac or ibuprofen used.