Manubriosternal joint

A critical joint that connects the upper part of the sternum to the body of the sternum.

The manubriosternal joint is the symphysis formed where the manubrium, the upper segment of the sternum, meets the body of the sternum. This joint is classified as a secondary cartilaginous joint and is primarily made up of fibrocartilage, which provides a slight degree of mobility while maintaining stability at the front of the thoracic cage.

Terminologia Anatomica

articulatio manubriosternalis

System

Skeletal system

Function

The manubriosternal joint serves several pivotal functions in the human body. Primarily, it facilitates the expansion and contraction of the thoracic cage during respiration. As the ribcage moves in and out, the flexible nature of this joint allows for slight adjustments, enhancing the efficiency of lung inflation and deflation. Furthermore, this joint contributes to the structural integrity of the sternum, which protects vital organs such as the heart and lungs from trauma. The stability provided by the manubriosternal joint also supports the attachment of the first few ribs, playing a key role in upper body mechanics and movements, such as lifting and twisting actions.

Location

The manubriosternal joint is located in the anterior thorax, specifically at the sternal angle, which is the junction between the manubrium and the body of the sternum. This area can be palpated at the level of the second rib, making it an important landmark for clinicians. It sits above the xiphoid process and below the clavicular notches (where the clavicles articulate with the sternum), forming a central point of convergence for the ribs and contributing to the formation of the thoracic cavity.

Did You Know?

The manubriosternal joint plays a role in measuring heart size and mediastinal conditions during clinical examinations.
Although this joint is largely immobile, it can exhibit tiny movements during intense physical activities such as heavy lifting.
The joint can sometimes develop conditions like osteoarthritis, which can lead to discomfort and restricted movement.