Lateral border of sternum.
Anterior surface of sternum and costal cartilages. (Sternal angle not labeled, but visible at second costal cartilage.)
|Latin||angulus sterni, angulus sternalis|
The sternal angle or angle of Louis, from the Latin angulus Ludovici is 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.
The sternal angle, which varies around 162 degrees in males, marks the approximate level of the 2nd pair of costal cartilages, which attach to the second ribs, and the level of the intervertebral disc between T4 and T5. In clinical applications, the sternal angle can be palpated at the T4 vertebral level. The angle also marks a number of other features:
- Boundary between the superior and inferior portion of the mediastinum
- Passage of the thoracic duct from right to left behind esophagus
- Tracheal Bifurcation
- End of the azygos system into SVC
- Ligamentum arteriosum
- Loop of left recurrent laryngeal nerve around aortic arch
- Aortic arch starts and ends
- Dalley, Arthur F.; Moore, Keith L. Clinically Oriented Anatomy. Hagerstown, MD: Lippincott Williams & Wilkins. ISBN 0-7817-5936-6.
- Gray's Anatomy 40th edition. Chapter 54: Chest wall and breast: Churchill Livingstone Elsevier. 2008. p. 922. ISBN 978-0-8089-2371-8.
- Anatomy photo:18:st-0212 at the SUNY Downstate Medical Center - "Thoracic Wall: Bones"