These compounds are also known as "fixed" or "immovable" joints, because they do not move. These compounds have no joint cavity and are connected by connective tissue. The cranial bones are connected by fibrous joints:

      The filaments are found between the bones of the skull. In fetal skulls the sutures are wide to allow slight movement during birth. Later stiff (synarthrodial).Syndesmotic between long bones of the body, such as the radius and ulna in the forearm and the calf and shin found in bone. Unlike other fibrous joints are movable syndesmoses (amphiarthrodial), albeit not as much as synovial joints.Gomphosis is a joint project between the tooth root and sockets in the upper or lower jaw.

Fibrous joints are united by dense connective tissue, consisting mainly of collagen.