Cranioplasty with a frozen and autoclaved bone flap.

27 cases of cranioplasty with autogenous bone grafts stored in a deep-freezer and autoclaved before use are reported. The results of follow-up for an average period of one year were satisfactory from the standpoint of brain protection and cosmetic reconstruction. A small area of absorption of grafted bone was observed in two cases on the follow-up skull roentgenograms. No serious complications were seen except in one case, whose bone flap had to be removed due to an epidural abscess. Experiments revealed that deep-freezing and autoclaving had only minimal effects on bone structure, although osteocytes degenerated. Autogenous bone flap after deep-freezing is a useful material for cranioplasty but sterilization before use is indispensable. Autoclaving is a simple method for sterilization of the flap, available in any operating theatre. It does not increase the risk of postoperative complications such as infection or absorption.