A form of nonunion in which there is the formation of a false joint with some cartilage covering the ends of the bones and a cavity containing fluid that resembles a normal joint.

When a solid fusion is not obtained after fusion surgery.

A false joint, as that sometimes seen following a fracture or in failure of an arthrodesis or fusion

Failure of fusion to achieve proper union of vertebrae

Pseudarthrosis (or "nonunions") is the movement of a bone at the location of a fracture resulting from inadequate healing of the fracture.