Sternocostal joints
Articulationes sternocostales
Definition
The sternocostal joints form the junction between the sternal ribs and the sternum. These are synovial joints whose generally thin joint capsule is reinforced by a dorsal thickening and a ventral thickening called radiate sternocostal ligament.
The sternocostal joints articulate the first eight costal cartilages to the successive intersternal cartilages of the sternum, with the exception of the first rib, whose transversely flattened costal cartilage articulates directly with the enlarged cranial portion of the manubrium.
The joints of the second to seventh pairs are typical.
The ninth pair of sternocostal joints is the last and does not have a synovial cavity. Its right and left costal cartilages meet medially and are connected by a collagen ligament. Attached to the cartilages of the eighth rib, they articulate with the ventral surface of the intersternal fibrocartilage located between the last two sternebrae, or with the cranial sternebra at the xiphoid process.
References
Evans HE, de Lahunta A. Miller’s Anatomy of the Dog. 5th ed. St. Louis: Elsevier; 2013. Chapter 4, The skeleton; p. 80–157.
Evans HE, de Lahunta A. Miller’s Anatomy of the Dog. 5th ed. St. Louis: Elsevier; 2013. Chapter 5, Athrology; p. 158–184.
