1. The anterior angle formed by the junction of the manubrium and the body of the sternum (the manubriosternal junction) in the form of a secondary cartilaginous joint (symphysis). This is also called the manubriosternal joint or Angle of Louis. The sternal angle is a palpable clinical landmark. (wikipedia.org)
2. The angle between the manubrium and the body of the sternum at the manubriosternal junction. Marks the level of the second costal cartilage (rib) for counting ribs or intercostal spaces. Denotes level of aortic arch, bifurcation of trachea, and T4/T5 intervertebral disc. (biology-online.org)
Syn: Sternal angle, angulus sterni, louis’ angle, ludwig’s angle, manubriosternal junction.
Word origin: Named after Pierre Charles Alexandre Louis, a French physician.