151. A cadaveric precision and accuracy analysis of augmented reality mediated percutaneous pedicle implant insertion

Abstract

BACKGROUND CONTEXT Augmented reality mediated spine surgery (ARMSS) is a minimally invasive novel technology that has the potential to increase the efficiency, accuracy, and safety of conventional percutaneous pedicle screw insertion methods. Visual 3-dimensional (3D) spinal anatomic and 2-dimensional (2D) navigation images are directly projected onto the operators’ retina and superimposed over the surgical field eliminating field of vision and attention shift to a remote display. The objective of this study was to assess the accuracy and precision of percutaneous ARMSS pedicle implant insertion. PURPOSE To assess the clinical accuracy and technical precision of head-mounted display (HMD) augmented reality (AR) assisted percutaneous pedicle screw insertion. STUDY DESIGN/SETTING Cadaveric accuracy and precision study. PATIENT SAMPLE Not applicable. OUTCOME MEASURES Not applicable. METHODS Five cadaveric torsos were ARMSS instrumented with the xvision AR-HMD platform (Augmedics; Chicago, IL) at levels ranging from T5 to S1 for a total of 113 total implants comprised of 93 pedicle screws and 20 jamshidi needles. Postprocedural computed tomography (CT) scans were graded by two independent neuroradiologists using the Gertzbein scale (GS A-E) for clinical accuracy. Technical precision was calculated via superimposition analysis employing the Medical Image Interaction Toolkit (MITK; Heidelberg, Germany) to yield angular trajectory (°) and screw tip (mm) linear deviation from the virtual pedicle screw position vs the actual pedicle screw position on post-procedural CT imaging. RESULTS The overall implant insertion clinical accuracy achieved was 99.1%. Sacro-lumbar and thoracic clinical accuracy was 100% and 98.3%, respectively. Specifically, among all implants inserted, 112 were noted to be GS A or B (99.12%) with only 1 medial GS C breach (>2 mm pedicle breach) in a thoracic pedicle at T9. Precision analysis of inserted pedicle screws yielded a mean screw tip linear deviation of 1.98 mm [99% CI:1.74 – 2.21 mm] and a mean angular error of 1.29° [99% CI:1.11° – 1.46°] from the projected trajectory. The latter data compare favorably to existing navigation platforms and regulatory precision requirements mandating that linear and angular deviation be below 3 mm (p CONCLUSIONS Percutaneous ARMSS pedicle implant insertion is a technically feasible, accurate, and highly precise method. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.