Intervertebral joints are examples of which joint category?

• A. Fibrous joints
• B. Synovial joints
• C. Bony joints
• D. Cartilaginous joints (amphiarthroses)

Answer: (D)

The concept here is how joints are classified by the tissue that binds them and how much movement they allow. Intervertebral joints are held together by an intervertebral disc, a pad of fibrocartilage between adjacent vertebrae. This places them in the cartilaginous joint category, specifically a symphysis-type joint. Cartilaginous joints with fibrocartilage like this are designed for limited, controlled movement, which is described as amphiarthrosis. That’s why intervertebral joints are best described as cartilaginous joints (amphiarthroses).

Fibrous joints are bound by dense connective tissue and are usually immovable or only slightly movable. Bony joints are where bones have fused into one. Synovial joints have a joint capsule and synovial fluid and are typically freely movable. The facet joints in the spine are synovial joints, but they’re a different articulation from the intervertebral discs themselves.