Structural Joints: Cartilaginous Joints

Cartilaginous joints are formed when bones are connected by cartilage, a strong but flexible connective tissue. These joints may be slightly movable and do not have a synovial cavity.

Cartilaginous joints are classified into two types based on the connecting cartilage — synchondroses, where hyaline cartilage joins the bones, and symphyses, where fibrocartilage connects them.

Synchondroses are mostly immovable or synarthrotic joints. They can be either temporary or permanent.

The joint in a child's bone between the metaphysis and the epiphysis is a temporary synchondrosis connected by epiphyseal cartilage. After puberty, the epiphyseal cartilage is replaced by bone, and then the metaphysis and epiphysis fuse.

In contrast, the joint between the first rib and the manubrium is a permanent synchondrosis connected by costal cartilage.

Symphyses are amphiarthrotic, which means that they allow limited movement.

For example, the joint connecting the pubic bones through a compressible and shock-absorbing fibrocartilage disc is a symphysis.