What is distraction osteogenisis?

Bone lengthening. Its a procedure where a bone is cut and then slowly the two ends are pulled apart over time, allowing new bone to form in the gap. It is used to lengthen long bones in the body and correct inequalities due to congenital or acquired deformities.
Lengthen bones. Distraction osteogenesis involves cutting a bone, and then putting an "erector set" apparatus on the two segments and gradually moving the two segments apart by activating the "erector set". It is used in long bones, fingers and toes, facial and skull bones, ribs, you name it.