Cartilaginous joints
Juncturae cartilagineae
Also known as: amphiarthrosis, synchondrosis, symphysis, primary cartilaginous joint, secondary cartilaginous joint
Joints in which bones are united by cartilage, without a joint cavity. Primary joints (synchondroses) use hyaline cartilage; secondary joints (symphyses) use fibrocartilage and lie in the midline.
Overview
Primary cartilaginous joints (synchondroses) unite bones with hyaline cartilage. Most are temporary, permitting growth, and are replaced by bone (synostosis) at maturity: the epiphyseal plates, the spheno-occipital synchondrosis and the triradiate cartilage. Permanent examples are the first sternocostal joint and the costochondral joints. They are immovable.
Secondary cartilaginous joints (symphyses) have articular surfaces covered by thin hyaline cartilage joined by a pad of fibrocartilage. They are strong, slightly movable (amphiarthroses) and all lie in the midline: the intervertebral discs, the pubic symphysis, the manubriosternal joint and the xiphisternal joint. Movement at each is small, but summed along the vertebral column it is considerable.
- Location
Growth plates, first sternocostal joint (synchondroses); intervertebral discs, pubic symphysis, manubriosternal joint (symphyses).
Parts & subdivisions
- Hyaline cartilage; mostly temporary growth joints.
- Fibrocartilage pads; midline; slightly movable.
Function
- Allow bone growth (synchondroses)
- Permit limited movement with great strength and shock absorption (symphyses)
Clinical significance
Manubriosternal joint in disease
The manubriosternal symphysis may be involved in seronegative spondyloarthropathies (ankylosing spondylitis) and rheumatoid arthritis.
Compiled from standard anatomy and physiology references — see the Skeletal System sources. For education only; not medical advice.