Pseudarthrosis

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

Pseudarthrosis can also result from a developmental failure.

Etymology
The Latin root "pseud" means false and "arthrosis" means joint. "Pseudarthrosis", then, is a false joint. In the case of a 'non-union', a fracture that does not heal, this is often evidenced by the obliteration of the medullary cavity of a long bone at the site of the non union. This non union is not a true joint, and has no ligamentous support, but often has motion, and remodels into a rounded end that looks like a true joint.

Treatment
The point of movement can be treated with electrical stimulations that hopefuly will trigger the bone cells to form the hydroxyapatite structure that keeps bones from bending too much. More recently, non-unions are treated by bone grafting, internal fixation, and external fixation, including a technique pioneered by Ilizarov, used to compress the bones at the site of the fracture.

More recently, non-unions are treated by bone grafting, internal fixation, and external fixation, including a technique pioneered by Ilizarov, used to compress the bones at the site of the fracture. Ilizarov originally used Bicycle spokes. Grafting This is using donor bone or autologous bone (harvested from the same person undergoing the surgery) as a stimulus to bone healing. The presence of the bone is thought to cause stem cells in the circulation and marrow to form cartilage, which then turns to bone, instead of a fibrous scar that forms to heal all other tissues of the body. Bone is the only tissue that can heal without a fibrous scar. Fixation The use of metal plates, pins, screws, and rods, that are screw or driven into a bone, to stabilize the broken bone fragments.