Updated December 15, 2014.

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

A craniotomy is a surgery during which a piece of the skull (a bone flap) is removed in order to allow a surgeon access to the brain. After the surgery is performed, the bone flap is returned to its previous location, where it can heal and mend like any broken bone. In many cases, metal plates are used to hold the bone flap in place so that it can heal, much like a cast for a broken arm.

A craniectomy procedure also includes the removal of a bone flap, but in this case it is not returned to its location after the procedure is finished.

This may be due to trauma to the bone itself, because the brain is too swollen to permit the return of the bone flap, or because the surgeon feels it is in the patient’s best interest. If there is infection in the area, for example, the bone flap may be discarded.

If a bone flap is removed, but not able to be returned during the procedure, it can still be put back into place at a later time. In this situation, the surgeon will place the bone flap in another location. In most cases, the surgeon will place the flap in the abdomen, under the fatty tissue, where it is protected and preserved by the patient’s own body.

If the bone flap cannot be returned, prosthetics and artificial bone are also available to aid the reconstruction at a later date.

<sub>Sources:

Bone Flap Management In Neurosurgery. Rev Neurocienc 2008. Accessed January 2010. http://www.unifesp.br/dneuro/neurociencias/229_revisao.pdf</sub>