A new method for cranial vault reconstruction: Augmented reality in synostotic plagiocephaly surgery

Augmented reality (AR) is considered to be a valuable tool in craniofacial surgery for preoperative design, intraoperative navigation, and postoperative assessment. Corrective surgery is necessary synostotic plagiocephaly for functional and aesthetic outcomes. Open calvarial reconstruction is a difficult classic surgical procedure with a high accuracy requirement. The purpose of this study was to introduce an AR system application in synostotic plagiocephaly surgery. Seven plagiocephaly patients (ages 6 months–24 months, average 16.7 months) were enrolled. Preoperative design was accomplished based on three-dimensional computed tomography (CT) data for patients with synostotic plagiocephaly. We completed the registration with the predefined markers through an image registration process preoperatively. Then, we overlaid the registration results into the surgical field to assist surgeons intraoperatively. CT scans were performed postoperatively. Intracranial volume was measured to judge the surgical outcomes. We performed a quantitative craniometric analysis between the planning of the reconstruction and post-operative results, and the main evaluation indicator was the intracranial volume asymmetry. We successfully applied the AR system in patients undergoing synostotic plagiocephaly, providing real-time navigational images of position and orientation information during open calvarial reconstruction surgery in 7 plagiocephaly patients within a span of 5 years. Good appearances were observed after the surgery. Cranial volume asymmetry was decreased from 27.87% to 16.57%, achieving precise intra-operative goals. No significant differences were found between planning and post-operative results. The AR system can be applied to plagiocephaly procedures guiding to obtain reliable and accurate results via a precise osteotomy.