Modified acrylic cranioplasty for large cranial defects.

Objective: To describe a novel technique for constructing polymethylmethacrylate (acrylic) cranioplasty to repair large cranial defects.

Methods: A rim of bone is cut from the edge of the skull defect using a craniotome. This bony rim provides a scaffold to fashion the acrylic cement away from the patient thus avoiding thermal injury to the brain. The inner edge of the bony rim is drilled circumferencially to form a groove. Acrylic is then used to fill the defect in the bony rim with continuous manipulation of the paste from both sides to form a dome in the shape of the skull. The groove allows the edge of the acrylic dome to fit snugly with the bony rim thus avoiding sinking. The final cranioplasty, comprised of the hardened acrylic dome with the surrounding bone rim, is firmly attached to the skull with bioplates.

Results: We used the modified acrylic cranioplasty technique in three patients. Modified acrylic cranioplasty is cheaper and immediately available, compared with ten cases of titanium cranioplasty, with similar cosmetic outcome, intraoperative blood loss and operating theatre time.

Conclusion: Our technique is quick and easy to perform, avoids thermal injury to the brain and produces a strong implant with excellent cosmesis even with large bony defects.