Airo® navigation versus freehand fluoroscopy technique: A comparative study of accuracy and radiological exposure for thoracolumbar screws placement

Computer tomography-assisted 3-dimensional navigation in spine surgery: a narrative review on safety, accuracy, efficacy and reduction of complications

The computed tomography-assisted 3D navigation system is a useful tool for spinal surgeons, enabling them to enhance the effectiveness and safety of surgical procedures by providing real-time three-dimensional information during decompression, resection, and instrumentation. Specific advantages of this navigation system include precise pedicle screw placement, the capability for immediate intraoperative correction, and execution of minimally invasive surgeries with reduced radiation exposure for the surgical team. Noteworthy disadvantages of this system are the relatively high implementation costs, the need for specific training, and limited accessibility to outpatient surgery centers. Currently, spinal navigation systems are constantly being upgraded with additional innovations, such as integration with robotics and improvement of the existing tools, which will ultimately lead to a better quality of life for patients and an improved experience for surgeons.

A systematic review and meta-analysis of radiation exposure in spinal surgeries: Comparing C-Arm, CT navigation, and O-Arm techniques

INTRODUCTION

Advanced imaging techniques, such as C-arm fluoroscopy, O-arm, and CT navigation, are integral to achieving precision in orthopedic surgeries. However, these technologies also expose patients, surgeons, and operating room staff to varying levels of radiation. This systematic review and meta-analysis evaluate the radiation exposure (RE) associated with these imaging modalities and their impact on surgical outcomes.

METHODS

A comprehensive literature search was conducted following PRISMA guidelines, resulting in 2,725 identified articles. After removing duplicates and screening for eligibility, 24 studies were included in the analysis. Radiation exposure data, measured in milliSieverts (mSv) and milliGray (mGy), were standardized using conversion formulas. Quality assessments were performed using the Newcastle-Ottawa Scale (NOS) and ROB2 tools. Statistical analysis was conducted using random-effects models for comparing radiation exposure and fixed-effects models for secondary outcomes.

RESULTS

The meta-analysis included 11 studies: 8 studies comparing C-arm and CT navigation, and 3 studies comparing C-arm and O-arm technologies. The analysis revealed that CT navigation is associated with significantly higher RE compared to C-arm (Standardized Mean Difference (SMD): 4.73, 95% Confidence Interval (CI): 2.44 to 7.03; p < 0.0001). In contrast, there was no significant difference in RE between O-arm and C-arm (SMD: 1.34, 95% CI: -0.17 to 2.85; p = 0.082). Secondary analyses showed no significant differences in surgery duration or hospitalization length between CT navigation and C-arm techniques.

DISCUSSION

The results of this meta-analysis underscore the trade-offs between radiation exposure and surgical precision. While CT navigation significantly increases RE compared to C-arm fluoroscopy, it offers superior accuracy, particularly in critical precision surgeries such as spinal interventions. The lack of significant difference in RE between O-arm and C-arm technologies suggests that O-arm may provide a balanced approach, offering enhanced accuracy with radiation levels similar to C-arm. However, the significant heterogeneity among studies and inconsistent reporting of secondary outcomes indicate the need for further research. Future studies should focus on refining imaging techniques to optimize the balance between radiation safety and surgical accuracy.

CONCLUSION

C-arm imaging generally results in lower radiation exposure compared to CT navigation, making it preferable for standard procedures where extreme precision is not as critical. However, CT navigation's superior accuracy justifies its use in precision surgeries despite the higher radiation exposure. O-arm technology, with its comparable RE to C-arm and enhanced accuracy, represents a beneficial option where available. Ongoing research should aim to optimize imaging techniques, balancing the need for radiation safety with the demands for surgical precision.

Higher Accuracy and Better Clinical Outcomes in Navigated Thoraco-Lumbar Pedicle Screw Fixation Versus Conventional Techniques : A Systematic Review and Meta-Analysis

STUDY DESIGN

A systematic review and meta-analysis.

OBJECTIVE

This study aims to compare pedicle screw accuracy, clinical outcomes, and complications between navigated and conventional techniques.

SUMMARY OF BACKGROUND DATA

In the last decades, intraoperative navigation has been introduced in spinal surgery to prevent risks and complications.

MATERIALS AND METHODS

The search was executed on Cochrane Central Library, PubMed, and Scopus on April 30, 2023. Randomized controlled trials, prospective and retrospective studies that compared pedicle screw accuracy in the thoracic-lumbar-sacral segments, blood loss, operative time, hospital stay, intraoperative and postoperative revision of screws, neurological and systemic complications, Visual Analogue Scale (VAS), and Oswestry Disability Index (ODI) between navigated and freehand or fluoroscopy-assisted techniques were included in this study. The meta-analysis was performed using Review Manager software. Clinical outcomes were assessed as continuous outcomes with mean difference, while pedicle screw accuracy and complications were assessed as dichotomous outcomes with odds ratio, all with 95% CIs. The statistical significance of the results was fixed at P <0.05.

RESULTS

This meta-analysis included 30 studies for a total of 17,911 patients and 24,600 pedicle screws. Statistically significant results in favor of the navigated technique were observed for the accuracy of pedicle screws ( P =0.0001), hospital stay ( P =0.0002), blood loss ( P <0.0001), postoperative revision of pedicle screws ( P <0.00001), and systemic complications ( P =0.0008). In particular, the positioning of the screws was clinically acceptable in 96.2% of the navigated group and 94.2% with traditional techniques. No significant differences were found in VAS, ODI, and operative time between the two groups.

CONCLUSION

Navigated pedicle screw fixation has been demonstrated to be a safe and effective technique with high improvement in clinical outcomes and accuracy in patients undergoing spinal fusion compared with conventional techniques.

LEVEL OF EVIDENCE

Level III.

[Intraoperative navigation of a distraction injury of the thoracic spine with very severe scoliotic alterations]

The case of a 43-year-old male patient is described, who suffered several injuries due to a traffic accident, including a distraction injury to the thoracic spine. A specific feature of this case was the existing spondylodesis with material fracture and secondary loss of reduction. Due to this, the guidewires of the pedicle screws were placed in a navigation pattern in the absence of adjustable pedicles and an abnormal screw corridor. This guarantees an optimal positioning with associated patient safety.