Using the head as a mould for cranioplasty with methylmethacrylate

Abstract

Methacrylate is a valuable tool to the neurosurgeon, even though it is currently being replaced by custom bone. During cranioplasty in the absence of custom bone, which is preformed based on the patients imaging, one has to make a cast to cover the cranial defect with or without the use of a mould. A good artificial skull outline is necessary for prevention of implant extrusion and acceptable cosmetic outcome. Using the patients head as a mould is a simple, cheap, and useful technique. An incision is made, and either a craniectomy or an attempt at skull elevation or separation of the scalp from dura is done based on the indication for the cranioplasty. The methacrylate monomer is mixed with its solvent. It is placed in between a sliced glove and then thinned out. Several layers of drapes are placed on the patients head, the acrylate which is in between the gloves is then placed on the drapes. As soon as it starts setting and the required shape obtained, it is removed and place on the sterile tray. It is then anchored and the wound closed. This technique produces good cosmetic outcome. However, the head must be properly protected from the risk of burns from the exothermic reaction. The technique is described in a 40-year-old driver who had a compound depressed skull fracture. He had a methylmethacrylate cranioplasty in the 9(th) week post trauma after allowing for wound healing. We recommend that this technique may be used in centers where custom bone is either too expensive or not available during cranioplasty in order to obtain a good outcome.

Keywords: Acrylate; cranial defects; cranioplast; cranioplasty; decompressive craniectomy; head; mould; polymethylmethacrylate.

Figure 1

Acrylate placed between the sliced gloves and thinned out with it placed over layers of drapes

Figure 2

Using the head as a mould