Use of Intraoperative CT Improves Accuracy of Spinal Navigation During Screw Fixation in Cervico-thoracic Region

Accurate Placement and Revisions for Cervical Pedicle Screws Placed With or Without Navigation: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

To evaluate the accuracy of placement for cervical pedicle screws with and without the use of spinal navigation.

METHODS

A structured search was conducted in electronic databases without any language or date restrictions. Eligible studies reported the proportion of accurately placed cervical pedicle screws measured on intraoperative or postoperative 3D imaging, and reported whether intraoperative navigation was used during screw placement. Randomized Studies (MINORS) criteria were used to evaluate the methodological quality of how accuracy was assessed for cervical pedicle screws.

RESULTS

After screening and critical appraisal, 4697 cervical pedicle screws from 18 studies were included in the meta-analysis. The pooled proportion for cervical pedicle screws with a breach up to 2 mm was 94% for navigated screws and did not differ from the pooled proportion for non-navigated screws (96%). The pooled proportion for cervical pedicle screws placed completely in the pedicle was 76% for navigated screws and did not differ from the pooled proportion for non-navigated screws (82%). Intraoperative screw reposition rates and screw revision rates as a result of postoperative imaging also did not differ between navigated and non-navigated screw placement.

CONCLUSIONS

This systematic review and meta-analysis found that the use of spinal navigation systems does not significantly improve the accuracy of placement of cervical pedicle screws compared to screws placed without navigation. Future studies evaluating intraoperative navigation for cervical pedicle screw placement should focus on the learning curve, postoperative complications, and the complexity of surgical cases.

Advances and Challenges of Endoscopic Spine Surgery

The purpose of this paper is to review the data supporting current endoscopic surgical techniques for the spine and the potential challenges and future of the field. The origins of endoscopic spine surgery can be traced back many decades, with many important innovations throughout its development. It can be applied to all levels of the spine, with many robust trials supporting its clinical outcomes. Continued clinical research is needed to explore its expanding indications. Although the limitations of starting an endoscopic program can be justified by its cost effectiveness and positive societal impact, challenges facing its widespread adoption are still present. As more residency and fellowship programs include endoscopy as part of their spine training, it will become more prevalent in hospitals in the United States. Technological advancements in spine surgery will further propel and enhance endoscopic techniques as they become an integral part of a spine surgeon's repertoire.

Full Endoscopic Spine Surgery with Image-Guided Navigation System as "Hybrid Endoscopic Spine Surgery": A Narrative Review

Endoscopic surgery is adopted as a minimally invasive technique in several surgical fields. Endoscopic spine surgery (ESS) was performed initially for lumbar discectomy but is currently widely utilized for various pathologies. Similar to other endoscopic techniques, ESS has a steep learning curve that has recently been a topic of discussion. Image-guided navigation systems have been developed for spine surgery. Intraoperative computed tomography enables the use of an image-guided navigation system in ESS, which is a suitable approach for managing complex lesions. Full-ESS is currently being adopted for certain cervical pathologies, and the incorporation of an image-guided navigation system will soon enable surgery for other cervical pathologies.

The Role and Future of Endoscopic Spine Surgery: A Narrative Review

Many types of surgeries are changing from conventional to minimally invasive techniques. Techniques in spine surgery have also changed, with endoscopic spine surgery (ESS) becoming a major surgical technique. Although ESS has advantages such as less soft tissue dissection and normal structure damage, reduced blood loss, less epidural scarring, reduced hospital stay, and earlier functional recovery, it is not possible to replace all spine surgery techniques with ESS. ESS was first used for discectomy in the lumbar spine, but the range of ESS has expanded to cover the entire spine, including the cervical and thoracic spine. With improvements in ESS instruments (optics, endoscope, endoscopic drill and shaver, irrigation pump, and multiportal endoscopic), limitations of ESS have gradually decreased, and it is possible to apply ESS to more spine pathologies. ESS currently incorporates new technologies, such as navigation, augmented and virtual reality, robotics, and 3-dimentional and ultraresolution visualization, to innovate and improve outcomes. In this article, we review the history and current status of ESS, and discuss future goals and possibilities for ESS through comparisons with conventional surgical techniques.

Patient radiation exposure from intraoperative computed tomography in spinal surgery

Intraoperative CT imaging is becoming increasingly used, but often little attention is paid to the underlying radiation exposure to the patient. This work showed that the dosimetrically assessed radiation exposure for cervical and lumbar 3D scans with an intraoperative CT is considerably higher than with a 3D C-arm. Therefore, proper selection of the intraoperative 3D imaging system is essential, and further technological developments and dose-saving protocols are warranted to further reduce patient radiation exposure.

Navigation Techniques in Endoscopic Spine Surgery

Endoscopic spine surgery (ESS) advances the principles of minimally invasive surgery, including minor collateral tissue damage, reduced blood loss, and faster recovery times. ESS allows for direct access to the spine through small incisions and direct visualization of spinal pathology via an endoscope. While this technique has many applications, there is a steep learning curve when adopting ESS into a surgeon's practice. Two types of navigation, optical and electromagnetic, may allow for widespread utilization of ESS by engendering improved orientation to surgical anatomy and reduced complication rates. The present review discusses these two available navigation technologies and their application in endoscopic procedures by providing case examples. Furthermore, we report on the future directions of navigation within the discipline of ESS.

Pedicle Screw Placement Using Intraoperative Computed Tomography and Computer-Aided Spinal Navigation Improves Screw Accuracy and Avoids Postoperative Revisions: Single-Center Analysis of 1400 Pedicle Screws

OBJECTIVE

Intraoperative computed tomography and navigation (iCT-Nav) is increasingly used to aid spinal instrumentation. We aimed to document the accuracy and revision rate of pedicle screw placement across many screws placed using iCT-Nav. We also assess patient-level factors predictive of high-grade pedicle breach.

METHODS

Medical records of patients who underwent iCT-Nav pedicle screw placement between 2015 and 2017 at a single center were retrospectively reviewed. Screw placement accuracy was individually assessed for each screw using the 2-mm incremental grading system for pedicle breach. Predictors of high-grade (>2 mm) breach were identified using multiple logistic regression.

RESULTS

In total, 1400 pedicle screws were placed in 208 patients undergoing cervicothoracic (29; 13.9%), thoracic (30; 14.4), thoracolumbar (19; 9.1%) and lumbar (130; 62.5%) surgeries. iCT-Nav afforded high-accuracy screw placement, with 1356 of 1400 screws (96.9%) being placed accurately. In total, 37 pedicle screws (2.64%) were revised intraoperatively during the index surgery across 31 patients, with no subsequent returns to the operating room because of screw malpositioning. After correcting for potential confounders, males were less likely to have a high-grade breach (odds ratio [OR] 0.21; 95% confidence interval [CI] 0.10-0.59, P = 0.003) whereas lateral (OR 6.21; 95% CI 2.47-15.52, P < 0.001) or anterior (OR 5.79; 95% CI2.11-15.88, P = 0.001) breach location were predictive of a high-grade breach.

CONCLUSIONS

iCT-Nav with postinstrumentation intraoperative imaging is associated with a reduced need for costly postoperative return to the operating room for screw revision. In comparison with studies of navigation without iCT where 1.5%-1.7% of patients returned for a second surgery, we report 0 revision surgeries due to screw malpositioning.

The combination of intraoperative CT navigation and C-arm fluoroscopy for INFIX and percutaneous TITS screw placement in the treatment of pelvic ring injury: technical note

Background

The subcutaneous screw rod system, commonly known as the internal pelvic fixator (INFIX), is useful in managing unstable pelvic ring fractures. Conventional INFIX and transiliac–transsacral (TITS) screw techniques are performed using C-arm fluoroscopy. There have been problems with medical exposure and screw insertion accuracy with these techniques. This work describes new INFIX and TITS techniques using intraoperative computed tomography (CT) navigation and C-arm fluoroscopy for pelvic ring fracture.

Methods

A typical case is presented in this study. An 86-year-old woman suffered from an unstable pelvic ring fracture due to a fall from a height. INFIX and TITS screw fixation with intraoperative CT navigation were selected to optimize surgical invasiveness and proper implant placement.

Results

The patient was placed in a supine position on a Jackson table. An intraoperative CT navigation was imaged, and screws were inserted under the navigation. Postoperative X-rays and CT confirmed that the screw was inserted correctly. This technique was less invasive to the patient and had little radiation exposure to the surgeon. Rehabilitation of walking practice was started early after the surgery, and she was able to walk with the assistance of a walker by the time of transfer.

Conclusions

The technique employed in our case study has the cumulative advantages of safety, accuracy, and reduced radiation exposure, together with the inherent advantages of functional outcomes of previously reported INFIX and TITS screw techniques. Further experience with this approach will refine this technique to overcome its limitations and facilitate its wider use.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-02920-0.

Workflow and performance of intraoperative CT, cone-beam CT, and robotic cone-beam CT for spinal navigation in 503 consecutive patients

OBJECTIVE

A direct comparison of intraoperative CT (iCT), cone-beam CT (CBCT), and robotic cone-beam CT (rCBCT) has been necessary to identify the ideal imaging solution for each individual user's need. Herein, the authors sought to analyze workflow, handling, and performance of iCT, CBCT, and rCBCT imaging for navigated pedicle screw instrumentation across the entire spine performed within the same surgical environment by the same group of surgeons.

METHODS

Between 2014 and 2018, 503 consecutive patients received 2673 navigated pedicle screws using iCT (n = 1219), CBCT (n = 646), or rCBCT (n = 808) imaging during the first 24 months after the acquisition of each modality. Clinical and demographic data, workflow, handling, and screw assessment and accuracy were analyzed.

RESULTS

Intraoperative CT showed image quality and workflow advantages for cervicothoracic cases, obese patients, and long-segment instrumentation, whereas CBCT and rCBCT offered independent handling, around-the-clock availability, and the option of performing 2D fluoroscopy. All modalities permitted reliable intraoperative screw assessment. Navigated screw revision was possible with each modality and yielded final accuracy rates > 92% in all groups (iCT 96.2% vs CBCT 92.3%, p < 0.001) without a difference in the accuracy of cervical pedicle screw placement or the rate of secondary screw revision surgeries.

CONCLUSIONS

Continuous training and an individual setup of iCT, CBCT, and rCBCT has been shown to permit safe and precise navigated posterior instrumentation across the entire spine with reliable screw assessment and the option of immediate revision. The perceived higher image quality and larger scan area of iCT should be weighed against the around-the-clock availability of CBCT and rCBCT technology with the option of single-handed robotic image acquisition.

O-Arm Assisted Cervicothoracic Spine Pedicle Screw Placement Accuracy Is Higher Than C-Arm Fluoroscopy

OBJECTIVE

We compared the accuracy of C-arm fluoroscopy versus O-arm-assisted pedicle screw (PS) placement in the cervicothoracic spinal junction (CTSJ).

METHODS

Patients who underwent PS placement in the CTSJ (C7-T4) at our hospital were included in this study. Of 37 patients who underwent PS placement in the CTSJ, 20 underwent intraoperative C-arm fluoroscopy-assisted surgery (C Group) and 17 underwent intraoperative O-arm-assisted surgery (O Group). In total, 159 PSs were placed-73 in the C Group and 86 in the O Group. The accuracy of PS placement was compared between the C Group and O Group using the classification proposed by Gertzbein and Robbins to analyze pedicle violation.

RESULTS

PS accuracy was higher in the O Group than C Group; PS placement evaluated as grade A, representing no perforation, was 95.3% (82/86) for the O Group, whereas it was 78.1% (57/73) for the C Group. There was a clear statistically significant difference in accuracy of PS placement between the groups (P = 0.0013).

CONCLUSIONS

O-arm-assisted surgery improved the accuracy of PS placement in the CTSJ.