Concept of the Week

The Structural and Functional Classification of Joints

Structurally, bones are classified according to the nature of the material that joins the bones together:

1. Fibrous Joints: The bone ends are united by collagenous fibers.

2. Cartilaginous Joints: The bone ends are united by cartilage (either fibrocartilage or hyaline cartilage).

3. Synovial Joints: The bone ends are covered with articular cartilage and enclosed within a joint capsule lined with synovial membrane.


Functionally, joints are classified according to the amount of movement permitted:

1. Synarthroses: Completely immovable joints (e.g. sutures)

2. Amphiarthroses: Slightly movable joints (e.g. interosseous membrane conncting radius to ulna)

2. Diarthroses: Joints that are freely movable in one or more planes of space (e.g. knee joint)