Costochondral joint (junction)
The costochondral joints are joints of the thoracic wall that connect the sternal ends of the ribs and their respective costal cartilages. They are structurally classified as primary cartilaginous joints (synchondrosis) in which bones are joined by hyaline cartilage.
There are ten pairs of costochondral joints between ribs 1-10 and their respective costal cartilages. These joints are immobile and are therefore functionally classified as synarthroses.
|Type||Primary hyaline cartilaginous joint (synchondrosis); synarthrosis|
|Articular surfaces||Sternal (medial) end of rib, lateral end of costal cartilage|
|Blood supply||Intercostal artery|
This article will cover the anatomy and function of the costochondral joints.
- Articular surfaces
- Joint capsule and ligaments
- Blood supply
- Muscles acting at the costochondral joint (junction)
The costochondral joint is a connection between a rib and its costal cartilage.
On the thoracic wall, it occurs where the bone ends and cartilage begins.
The joint is formed by two articular surfaces; the roughened cup-shaped anterior end of the rib and the rounded lateral end of the costal cartilage.
Joint capsule and ligaments
These joints have no joint capsule, cavity or ligaments. The periosteum of the rib is continuous the perichondrium of the costal cartilage, binding the bone and cartilage together.
The costochondral joints are supplied by branches of the intercostal nerves, which are the anterior rami of the thoracic spinal nerves.
The costochondral articulations themselves are immobile joints that do not permit movement. However, the costal cartilages provide a flexible attachment for the anterior ends of the ribs to the sternum and may undergo slight bending and twisting movements that facilitate widening of the thoracic diameters during breathing.
Muscles acting at the costochondral joint (junction)
Given the fact that this joint is immobile, no muscles have a direct action on the joint. The costochondral joints, however, provide surfaces of attachment for the anterior muscle fibers and aponeurosis of the intercostal muscles.