Nonsynovial

Nonsynovial joints are joints that lack a synovial cavity and are not lubricated by synovial fluid. They are connected by fibrous tissue or cartilage and typically permit little or no movement, or only slight movement, in contrast to synovial joints which feature a fluid-filled cavity and a wide range of motion.

There are two structural categories of nonsynovial joints: fibrous joints and cartilaginous joints. Fibrous joints are united by dense connective tissue rich in collagen. Subtypes include sutures, which connect the bones of the skull and are largely immovable in adults; syndesmoses, where bones are joined by interosseous ligaments (such as the distal tibiofibular joint or the radioulnar interosseous membrane); and gomphoses, where teeth anchor into their sockets in the jaw.

Cartilaginous joints are joined by cartilage. They include synchondroses, where bones are connected by hyaline cartilage (for example, early epiphyseal growth plates and some costal joints); and symphyses, where fibrocartilage unites bones (notably the pubic symphysis and the intervertebral discs). These joints can be synarthrotic (immovable) or amphiarthrotic (slightly movable) depending on the specific articulation and developmental stage.

In clinical and anatomical contexts, nonsynovial joints provide stability and support, with movement restricted compared to synovial joints. Changes in these joints—such as premature fusion of sutures in craniosynostosis or degeneration of cartilaginous joints with age—have distinct diagnostic and therapeutic implications.