Immovable Joint Health Article

Definition

An immovable joint is an articulation between bones in which no movement occurs. It is also referred to as synarthrotic (meaning immovable).

Description

An immovable joint can be either one of two types of joints, fibrous or cartilaginous. In a fibrous joint, there are two types of articulations that are considered immovable, suture and gomphosis.

A suture is a type of articulation in which the bones that make up the joint are close together. An analogy to this is the interlocking fashion exhibited by placing puzzle pieces together. In a suture, the union of bones is bound by connective tissue.

A gomphosis is a type of joint in which one bone fits into another bone. The articulating edges are bound together by connective tissue. Similar to the suture, the bony surfaces in the articulation are close together. An analogy to this is a wooden dowel fitting into a hole and held together by glue, with the dowel and hole representing the bony structures and the glue representing the connective tissue.

In a cartilaginous type of joint, there is one type of articulation that is considered immovable, the synchondrosis.

A synchondrosis is a joint in which the articulating surfaces are close together but are bound by hyaline cartilage. In a synchondrosis, the hyaline cartilage eventually converts to either bone or fibrocartilage.

Function

The function of the immovable or synarthrotic joint is to provide a stable union between bony surfaces. The suture and synchondrosis actually become more stable when ossification of the joint takes place.

KEY TERMS

Cartilaginous joint—A joint that represents the connection of two bones bound by either hyaline fibro or elastic cartilage.

Connective tissue—Tissue that has pliable fibers, which provide strength to the tissue.

Diaphysis—The center or shaft of a bone that is ossified.

Epiphysis—Considered a secondary center of ossification. This secondary center of ossification appears at the ends of long bone.

Fibrocartilage—Connective tissue made up of collagen fibers with less ground substance compared to hyaline cartilage.

Fibrous joint—Surfaces of two bones that are connected by fibrous tissue, which consists mainly of collagen fibers.

Hyaline cartilage—A mesh of collagen fibers and ground substance.

Proximal—The closest portion of a bone, structure, or other element that is close to the head of the body.

Synarthrosis—An immovable joint.