The sternal angle is the angle formed by the junction of the manubrium and the body of the sternum[1] (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.
It marks the approximate level of the 2nd pair of costal cartilages and the level of the intervertebral disc between T4 and T5. It also marks approximately the beginning and end of the aortic arch, and the bifurcation of the trachea into the left and right main bronchi.
