Autologous versus synthetic cranioplasty

Background. Cranioplasty has been described in history as far back as the 16th century. The use of autologous cranioplasty has been published since 1821 and is still under practice today worldwide. Recent evidence however has suggested increased complication and revision rates with the use of autologous bone. We compared our results of autologous cranioplasty versus synthetic material. Methods. A retrospective study was carried out of cranioplasty procedures at our unit between August 2009 and March 2018. Bone flaps were placed in a sterile sealed plastic container and stored at -81 degrees. Swabs and bone chips were used for cultures and bone flap disposed if positive. On re-implantation, the bone was thawed at room temperature and soaked in gentamicin. Synthetic cranioplasties were constructed using thin-slice CT to design a custom flap for each patient. Results. 144 cranioplasties were studied. 51 own bone and 93 synthetic. The average delay in cranioplasty was 286 days (Range 16 – 1264 days). The overall complication rate for all 144 cranioplasties was 20.8%; Autologous 31.4% and synthetic 15.1%; p 0.031. Bone flap infection rate overall for all 144 cases was 9.7% - Autologous 11.8% and Synthetic 8.6%; p 0.565. The revision rate was found to be 13.2% overall; 23.5% for autologous and 7.5% for synthetic. The difference in revision rate was found to be statistically significant (p 0.01). Conclusion. Revision rate and overall complication rate were higher in the own bone group with P<0.05. There was no difference in infection. Our results mirror recent publications and should be considered when undertaking a cranioplasty.