Pelvic Stabilization and Resection of Sacral Metastasis Utilizing Augmented Reality in Conjunction with Navigation: A Case Report and Video Illustration

Introduction: A 69-year-old male presented with 3 months of back pain, right leg numbness and weakness in an S1 distribution limiting ambulation. Imaging revealed a mass crossing the right sacroiliac joint involving S1-S3 vertebral bodies (8.1 x 7.3 x 7.1 cm). The purpose of this report is to present a case of augmented reality (AR) used in conjunction with navigation to assist with planning and execution of resection of a sacral tumor and pelvic instrumentation.

Methods: A retrospective review was conducted of the patient’s operative reports, and intraoperative imaging studies.

Results: The treatment plan consisted of a L4-pelvis fusion with resection of tumor. Pelvic screw trajectory was limited by the tumor and need to stabilize the pelvic ring. Lumbosacral construct included bilateral iliac in a trajectory typically utilized for a kickstand, S3 alar iliac, and L4-S1 pedicle screw fixation and L5-S1 cage placement. AR was used to plan both the incision and the initial dissection around the tumor, as well as the tumor resection and instrumentation. AR allowed for increased appreciation of the tumor and nearby structures, including anterior vascular structures and the pelvic ring in its entirety. Navigation to assist with instrumentation trajectory and AR to provide a better understanding of that trajectory within a wider anatomical field beyond the exposure. Patient suffered no intraoperative complications, and the hardware was verified with postoperative CT, with no cortical wall breach (Gertzbein-Robbins A).

Conclusion : AR is a promising tool, especially in conjunction with navigation, for allowing an appreciation of anatomy not typically within the surgical field, as well as decreasing operative time and the need for 2D imaging, such as fluoroscopy. It can be especially helpful when based on the anatomy and trajectory fluoroscopy cannot be utilized to confirm the navigation.