Original ArticleOptical Topographic Imaging for Spinal Intraoperative Three-Dimensional Navigation in Mini-Open Approaches: A Prospective Cohort Study of Initial Preclinical and Clinical Feasibility
Introduction
Intraoperative three-dimensional (3D) computer-assisted navigation (CAN) has become standard of care in cranial neurosurgery for the localization of subsurface anatomy. Spinal CAN often guides instrumentation placement and tissue resection; however, adoption has been limited by cumbersome and lengthy registration protocols, workflow hindrances, steep learning curves, and high costs.1, 2, 3, 4, 5, 6
The usefulness of CAN is most apparent in minimally invasive surgery (MIS) and deformity-correcting procedures, in which anatomic landmarks are not directly visible or are significantly distorted.1, 5, 7, 8 MIS techniques, through mini-open, tubular, and/or endoscopic approaches, have been shown to shorten hospital length of stay, minimize intraoperative blood loss, and improve short-term patient-reported outcomes. The impact on operative time and postoperative complications, relative to comparable open spinal procedures, remains to be defined.9, 10, 11, 12, 13, 14 However, MIS approaches have typically been guided by intraoperative fluoroscopy or computed tomography (CT). These techniques are associated with substantial radiation exposure and workflow disruption.15
Optical topographic imaging (OTI) is a novel technique for 3D surface acquisition, patient-to-image registration, and intraoperative navigation, developed by our research group. OTI registers significantly faster than CAN systems with comparable accuracy and without intraoperative radiation exposure.16 This technology obviates many of the limitations of CAN techniques.1, 5 In its current iteration, OTI requires line of sight to exposed bony anatomy to allow machine-vision cameras to generate a virtual 3D surface for patient-to-image registration. OTI has been validated only in open posterior thoracolumbar approaches with incisions exposing >3 spinal levels.
In this study, we assess the ability of OTI to perform successful patient-to-image registration and accurate intraoperative navigation in mini-open spinal procedures. We explore predictors of successful registration and their correlation with quantitative navigation accuracy.
Section snippets
Methods
Reporting of all methodology is performed in accordance with the criteria for STROBE (Strengthening the Reporting of Observational Studies in Epidemiology [www.strobe-statement.org]).
Results
For the 4 cadavers used in preclinical validation, mean age at death was 91.4 years (range, 83–96 years). Thirty-seven screws from the 4 cadavers were included in our analysis: 8 pedicle screws at T2, 10 at T6, 9 at T10, and 4 pedicle and 6 cortical screws at L3. One pedicle at T10 was not analyzed because of the unavailability of appropriate instrumentation to place at this level.
In vivo clinical feasibility was assessed in 8 patients, with mean age 57.2 years. Fifty-five thoracolumbar pedicle
Discussion
The primary purported benefit of CAN for spinal procedures is improved instrumentation accuracy and, in theory, minimization of acute and long-term complications from misplaced screws. CAN has been shown to reduce pedicle screw breach rates from 12%–40% with freehand or fluoroscopic guidance to <5% with 3D CAN.23, 24, 25, 26, 27, 28 Improved instrumentation accuracy is seen across all 3D CAN techniques, registering to preoperative or intraoperative imaging, in each of the cervical, thoracic,
Conclusions
Optical machine vision is a novel navigation technique previously validated for open posterior exposures. OTI is feasible for mini-open MIS exposures in preclinical and initial clinical testing, with comparable radiographic accuracy to that achieved by OTI in open exposures. The likelihood of successful registration depends on the number of points acquired and registered by the navigation system but not exposure size. With the exception of sagittal angular deviation, absolute navigation
Acknowledgments
This research is supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canada Foundation for Innovation (CFI). Salary support for D.G. was provided in part by a Canadian Institutes of Health Research (CIHR) postdoctoral fellowship (FRN 142931).
References (41)
- et al.
Worldwide survey on the use of navigation in spine surgery
World Neurosurg
(2013) - et al.
Surgeons’ perceptions of spinal navigation: analysis of key factors affecting the lack of adoption of spinal navigation technology
SAS J
(2008) - et al.
Learning curve of 3D fluoroscopy image-guided pedicle screw placement in the thoracolumbar spine
Spine J
(2015) - et al.
Economic evaluation comparing intraoperative cone beam CT-based navigation and conventional fluoroscopy for the placement of spinal pedicle screws: a patient-level data cost-effectiveness analysis
Spine J
(2016) - et al.
Spinal intraoperative three-dimensional navigation: correlation between clinical and absolute engineering accuracy
Spine J
(2017) - et al.
Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF): surgical technique, long-term 4-year prospective outcomes, and complications compared with an open TLIF cohort
Neurosurg Clin North Am
(2014) - et al.
Accuracy of C2 pedicle screw placement using the anatomic freehand technique
Clin Neurol Neurosurg
(2014) - et al.
Accuracy of single-time, multilevel registration in image-guided spinal surgery
Spine J
(2005) - et al.
Thoracolumbar instrumentation with CT-guided navigation (O-arm) in 270 consecutive patients: accuracy rates and lessons learned
Neurosurg Focus
(2014) - et al.
The surgical learning curve and accuracy of minimally invasive lumbar pedicle screw placement using CT based computer-assisted navigation plus continuous electromyography monitoring–a retrospective review of 627 screws in 150 patients
Int J Spine Surg
(2014)
Accuracy and workflow of navigated spinal instrumentation with the mobile AIRO(®) CT scanner
Eur Spine J
Navigation-assisted surgery for tumors of the spine
Eur Spine J
Segmental pedicle screwing for idiopathic scoliosis using computer-assisted surgery
J Spinal Disord Tech
Economics of image guidance and navigation in spine surgery
Surg Neurol Int
Minimally invasive versus open transforaminal lumbar fusion: a systematic review of complications
Int Orthop
Open versus minimally invasive fixation techniques for thoracolumbar trauma: a meta-analysis
Glob Spine J
Perioperative outcomes and adverse events of minimally invasive versus open posterior lumbar fusion: meta-analysis and systematic review
J Neurosurg Spine
Minimally invasive versus open laminectomy for lumbar stenosis
Spine (Phila Pa 1976)
Radiation exposure in spine surgery using an image-guided system based on intraoperative cone-beam computed tomography: analysis of 107 consecutive cases
J Neurosurg Spine
High speed, high density intraoperative 3D optical topographical imaging with efficient registration to MRI and CT for craniospinal surgical navigation
Sci Rep
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2022, Spine JournalCitation Excerpt :Individual vertebras can be registered to account for relative movement of spinal levels between surgery and the CT, but exposed bone is required for registration, limiting utility in minimally invasive procedures. Initial non-randomized reports using FLASH have demonstrated pedicle screw accuracy rates equivalent to contemporary 3D fluoroscopic IGS, whilst providing a reduction in time and radiation by eliminating the need for intraoperative 3D fluoroscopy [4,9,11–14]. A prospective clinical study of 171 craniospinal surgical procedures compared FLASH to 2 different 3D fluoroscopy-based navigation systems showed no significant differences between breach rates with decreased registration and setup time (41s vs. 258s and 794s) [11].
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Conflict of interest statement: V.X.D.Y. is co-founder and Chief Scientific Officer of 7D Surgical Inc., a company licensing the OTI technology described in this article. There are no material or financial conflicts of interest arising from this study. The remaining authors have no relevant conflicts of interest to disclose. This research is supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canada Foundation for Innovation (CFI). Salary support for D.G. was provided in part by a Canadian Institutes of Health Research (CIHR) postdoctoral fellowship (FRN 142931).