According to a presentation from the American Association of Neurological Surgeons Annual Scientific Meeting, optical topographic imaging is an efficient, novel technique that allows for initial and repeat registration of the cervical spine and had accuracy similar to other spinal neuronavigation systems.
“Optical surface imaging is a novel technique for patient-to-image registration and intraoperative navigation that allows rapid and efficient registration to minimize surgical workflow disruption without additional intraoperative radiation [and] that is safe and accurate for applications in the cervical spine,” Daipayan Guha, MD, told Healio.com/Orthopedics. Guha and colleagues won the Sanford J. Larson, MD, PhD, Award for their research.
He added, “Navigation can be performed accurately and safety in the cervical spine, much more efficiently than with the current navigation techniques. The hope is that surgeons will more readily adopt a less disruptive technology more readily than has been with the case with current navigation techniques, ultimately improving the accuracy of spinal instrumentation placement and therefore reducing the risk of complications for patients.”
Guha and colleagues performed an initial validation of the technology on four human cadavers. Thin-slice preoperative CT imaging was performed for intraoperative registration. Screw tracts at all levels were navigated with a track-drill guide. A total of 53 cadaveric screws were assessed. Investigators compared navigation data with screw position on postoperative CT imaging, and they computed absolute translational and angular deviations. Six patients who underwent open posterior cervical instrumentation were used for subsequent clinical validation.
Results showed the absolute translational errors in the axial and sagittal planes were 1.66 mm and 2.08 mm, respectively, and the absolute angular deviations were 4.11°and 6.96°, respectively. Investigators noted pedicle screws at C7 showed decreased axial translational error relative to the other screws after investigators adjusted for differences between cadavers.
Investigators assessed 22 clinical screws. According to researchers, the absolute translational errors in the axial and sagittal planes were 1.52 mm and 1.06 mm, respectively, and the absolute angular deviations were 3.69°and 2.83°, respectively. No differences in the errors were seen between levels and no facet, canal or foraminal violations and no neurovascular injuries were seen.
“We were expecting the accuracy of optical surface imaging to be comparable to what we have previously demonstrated in the thoracolumbar spine,” Guha said. “Surprisingly, in certain parameters of quantitative navigation accuracy, this technique appears to be even more accurate in the cervical spine than in the thoracolumbar spine, though not reaching statistical significance.”– by Monica Jaramillo
Guha D, et al. Paper #610. Presented at: American Association of Neurological Surgeons Annual Scientific Meeting; April 22-26, 2017; Los Angeles.
Disclosure: Guha reports no relevant financial disclosures.