Intraoperative risks of radiation exposure for the surgeon and patient

Radiation Shielding Effect of Surgical Loupes Compared with Lead-Lined Glasses and Plastic Face Shields

BACKGROUND

Fluoroscopy plays a crucial role in various medical procedures, especially in orthopaedic and spinal surgery. However, concerns have arisen regarding ocular radiation exposure given its association with posterior lens opacities and cataracts. Protective measures are essential to mitigate ocular radiation exposure. During spine surgery, loupes are frequently used but often lack lead lining. The purpose of the present study was to assess the effect of surgical loupes, as compared with lead glasses and plastic face shields, on ocular radiation exposure.

METHODS

Dosimeters were positioned anterior (unshielded) and posterior (shielded) to the lens of each type of eyewear: lead glasses, surgical loupes, and plastic face shields. Eyewear/dosimeters were exposed directly to the horizontal beam of a C-arm for 2 minutes of continuous fluoroscopy. This was repeated 20 times for each type of eyewear (40 total/eyewear, 120 times overall). Radiation doses were modeled with use of generalized estimating equations with a Gaussian distribution and identity link function. Separate models were employed for each outcome, including eyewear category (lead glasses, loupes, plastic shield) and dosimeter position (anterior/unshielded versus posterior/shielded).

RESULTS

Radiation dose was significantly lower in posterior compared with anterior dosimeters for lead glasses (0.00 versus 1,689.80 mRem; p < 0.001) and for loupes (20.27 versus 1,705.95 mRem; p < 0.001). The difference for plastic face shields did not reach significance (1,539.75 versus 1,701.45 mRem; p = 0.06). Lead glasses offered the most protection, followed by surgical loupes and then plastic shields, when comparing the shielded dosimeter readings (0.00 versus 20.27 versus 1,539.75; p < 0.001 for all comparisons). There was no significant difference in radiation dose for dosimeters placed anterior to lead glasses, loupes, and plastic face shields (1,689.80 versus 1,705.95 versus 1,701.45 mRem; p = 0.99).

CONCLUSIONS

Lead glasses were most effective (∼100% reduction), followed by surgical loupes (97%), whereas plastic face shields showed no significant reduction in radiation dose. Surgical loupes can substantially reduce ocular radiation exposure.

CLINICAL RELEVANCE

Surgical loupes may offer ocular radiation protection.

Pelvic asymmetry in children with neuromuscular scoliosis: a computed tomography-based 3D analysis

PURPOSE

Pelvic fixation in pediatric neuromuscular patients with scoliosis is performed when significant pelvic obliquity is present. Instrumentation to the pelvis can be technically demanding and challenging, often associated with a high complication rate, prolonged operative time, increased radiation exposure, and increased intraoperative bleeding. The high complexity of the pelvic instrumentation technique, particularly in severe cases, led us to develop computed tomography (CT)-based 3D in a series of 53 consecutive neuromuscular patients. This analysis aimed to improve the understanding of pelvic asymmetry and preoperatively simulate pelvic instrumentation.

METHODS

A CT-based 3D analysis of all pelvises was performed using Mimics software (version 21), segmenting them for analysis in all three planes. We proceeded with the simulation of pelvic instrumentation with iliac screws, obtaining the angle values and corresponding orientations in the three planes for each screw. A total of 53 CT scans were analyzed, corresponding to 36 patients with myelodysplasia and 17 with neuromuscular disorders.

RESULTS

Pelvic asymmetry was observed in 88.6% (47 CT scans) of the patients. This asymmetry indicated that the weight-bearing hemipelvis underwent anatomical changes compared to the contralateral hemipelvis, including opening or closing of the pelvis relative to the sacroiliac joint, pivoting of the hemipelvis in a cephalocaudal or caudocephalic direction, and shortening of the innominate line.

CONCLUSION

The shape of the weight-bearing hemipelvis is closely related to pelvic asymmetry. A distinct pattern was identified, characterized by cephalic or caudal pivoting, greater prominence of the iliac crest, increased distance from the sciatic spine to the coccyx, and shortening of the innominate line. This finding is relevant for surgical planning and pelvic fixation.

LEVEL OF EVIDENCE

IV.

AI-Driven Advances in Low-Dose Imaging and Enhancement-A Review

The widespread use of medical imaging techniques such as X-rays and computed tomography (CT) has raised significant concerns regarding ionizing radiation exposure, particularly among vulnerable populations requiring frequent imaging. Achieving a balance between high-quality diagnostic imaging and minimizing radiation exposure remains a fundamental challenge in radiology. Artificial intelligence (AI) has emerged as a transformative solution, enabling low-dose imaging protocols that enhance image quality while significantly reducing radiation doses. This review explores the role of AI-assisted low-dose imaging, particularly in CT, X-ray, and magnetic resonance imaging (MRI), highlighting advancements in deep learning models, convolutional neural networks (CNNs), and other AI-based approaches. These technologies have demonstrated substantial improvements in noise reduction, artifact removal, and real-time optimization of imaging parameters, thereby enhancing diagnostic accuracy while mitigating radiation risks. Additionally, AI has contributed to improved radiology workflow efficiency and cost reduction by minimizing the need for repeat scans. The review also discusses emerging directions in AI-driven medical imaging, including hybrid AI systems that integrate post-processing with real-time data acquisition, personalized imaging protocols tailored to patient characteristics, and the expansion of AI applications to fluoroscopy and positron emission tomography (PET). However, challenges such as model generalizability, regulatory constraints, ethical considerations, and computational requirements must be addressed to facilitate broader clinical adoption. AI-driven low-dose imaging has the potential to revolutionize radiology by enhancing patient safety, optimizing imaging quality, and improving healthcare efficiency, paving the way for a more advanced and sustainable future in medical imaging.

Diagnostic Performance of Advanced Tomosynthesis in Patients with Metal Devices in the Affected Knee: A Case Report

Simple radiography is the most frequently and widely available technology to examine bone pathologies. Computed tomography (CT) can evaluate pathologies more accurately in multiple planes and three dimensions; however, radiation exposure is much higher than with simple radiography. In addition, diagnostic ability is decreased for both technologies when metal devices are present. Tomosynthesis is a radiographic technology used to evaluate tissues quasi-three-dimensionally with less radiation exposure. Tomosynthesis technology was recently upgraded to reduce the effects of metal artifacts. This case report compares examination time, medical expense, image resolution, and radiation exposure for upgraded tomosynthesis, simple radiography, CT, and standard tomosynthesis in three patients with metal devices in the affected knees. Examination times were similar for the imaging technologies. Diagnostic performance was better for upgraded tomosynthesis than for simple radiography and standard tomosynthesis, and similar to that for CT. Moreover, radiation exposure and expense were higher for tomosynthesis than for simple radiography but lower than for CT. These findings suggest that upgraded tomosynthesis is the best method for evaluating bone pathology when metal devices are present and radiation exposure must be limited.

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.

Dimensionality Reduction and Electrode Arrangement Optimization for an Electric Field Source Seeking Surgical Navigation Method

This study proposes a Dimensionality Reduction Electric Field Source Seeking (EFSS) method for real-time, high-precision navigation in intracranial puncture surgeries. The method integrates internal localization electrodes and external potential measurement electrodes to minimize surgical trauma while ensuring the accurate localization and guidance of surgical instruments. To optimize the electrode arrangement, two evaluation metrics-Mean Response Coefficient (MRC) and MRC-mean-were introduced. The simulation results demonstrated the effectiveness of these metrics, with the optimal arrangement achieving an average localization error below 2 mm and a 56% reduction in error after optimization. Experimental validation was conducted using a brain model with conductivity properties similar to those of human tissue. Localization experiments confirmed the robustness and accuracy of the EFSS method, with all results showing consistent repeatability and monotonic trends in performance across different electrode configurations. This study highlights the potential of the dimensionality reduction EFSS method as a novel and effective approach for navigation in minimally invasive intracranial surgeries.

Exploring strategies to enhance patient safety in spine surgery: a review

Patient safety is the foundation of spine surgery, where the intricate nature of spinal procedures and the unique risks involved call for exceptional diligence and comprehensive protocols. In this high-stakes field, developing and implementing rigorous safety protocols is not only vital for minimizing complications but also for achieving the best possible outcomes and strengthening the confidence patients have in their care team. Each patient entrusts their well-being to their surgical team. This trust underscores the responsibility healthcare providers have to prioritize safety at every stage. In spine surgery, thorough preoperative planning, clear communication during informed consent, and vigilant postoperative care are all crucial for creating a safe environment tailored to each patient's needs. A commitment to patient safety requires more than individual efforts; it calls for a coordinated, multidisciplinary approach where surgeons, nurses, anesthesiologists, and rehabilitation specialists work closely together. This collaboration ensures that each step of the patient's journey is aligned with best practices for safety and care. This review highlights the critical need for ongoing evaluation and refinement of safety protocols in spine surgery. As surgical techniques and technologies advance, and as patients' needs evolve, healthcare teams must remain responsive, cultivating a culture of safety that is both proactive and adaptable. Continuous investment in quality improvement and research is essential to fine-tune these protocols, ensuring they remain both relevant and effective in addressing the unique challenges of spine surgery. Prioritizing comprehensive safety measures goes beyond improving surgical outcomes; it plays a pivotal role in strengthening the trust and confidence patients have in their healthcare providers. By committing to these robust protocols, we reaffirm our dedication to patient-centered care, enhancing not only patient safety and recovery but also fostering a deeper faith in a healthcare system that places patient well-being at the forefront.

'The Stegosaurus Appearance' on ultrasound to assist in identifying the correct spinal level for primary lumbar spinal surgery

Lumbar spinal surgery relies on palpation of anatomical landmarks and X-ray imaging confirmation to identify the correct spinal level, therefore exposing patients and staff to radiation, and increasing intraoperative time and cost. Ultrasound (US) assistance is being used to visualise spinal anatomy by many specialities, such as neurology and anaesthetics, and can be used intraoperatively in selected spinal surgery cases. However, its potential use to check spinal levels prior to surgery remains understudied. This prospective, pilot study screened all patients requiring a primary elective or emergency lumbar discectomy, under the supervision of a single consultant neurosurgeon, over an 8-month period at a single neurosurgical unit. US assistance was used to identify and mark the proposed spinal level prior to skin incision. The resemblance of the parasagittal lumbar US images to the back of the dinosaur Stegosaurus aided users in identifying the relevant anatomical structures necessary to mark the desired spinal level, (e.g., lumbar laminae, intervertebral spaces, sacrum). This inspired our description of the US images of the lumbar spine as 'The Stegosaurus Appearance'. The spinal level marked by US was then confirmed in the standard fashion using intraoperative X-ray imaging. In 100% of cases (12/12), the desired spinal level was correctly identified using US, confirmed by the subsequent intraoperative X-ray images. US assistance appears to be a safe, quick, and accurate tool for identifying the correct lumbar spinal level prior to skin incision, and could therefore represent a useful adjunct to supplement level checking in lumbar spinal surgery.

Thermal optimization of robotic piezoelectric osteotomy motion in porcine trabecular bone

BACKGROUND

Piezoelectric osteotomy represents a potentially viable alternative to conventional techniques for preparing pilot holes for bone screws. However, piezoelectric osteotomes have demonstrated the potential to heat bone beyond 47 °C, which induces necrosis that could contribute to screw loosening, resulting in osteosynthetic material failure and pseudarthrosis. Thus, we sought to determine the working movements of a piezoelectric drill that resulted in the lowest maximum bone temperatures while ensuring that this optimal drilling motion resulted in temperatures below 47 °C.

METHODS

Vertebrae samples were obtained fresh from a local abattoir. A robot was used to drill 15 mm holes through the vertebrae bodies parallel to a sectioned viewing surface, observed with a thermal camera. We tested three significant aspects of the osteotome's movement: the feed rate, retraction speed and working cycle to see which combination resulted in the lowest maximum temperatures. Each factor combination was tested three times for a total of 24 trials.

FINDINGS

A feed rate of 2 mm/s, a retraction speed of 2 mm/s and a novel working cycle termed "multi-pass" were found to generate the lowest maximum temperatures (41.5 °C, σ = 1.91 °C). The factors of retraction speed and working cycle demonstrated statistical significance through analysis of variance, with ordinary least squares regression indicating their optimal settings resulted in reductions in maximum temperatures of 4.95 °C and 5.63 °C, respectively.

INTERPRETATION

Robotic piezoelectric osteotomy appears to represent a safe method of pedicle screw pilot hole preparation from a thermal perspective when using the optimal methods found in this study.

Radiation Protection in the Orthopedics Department: Insights From a Cross-Sectional Study

OBJECTIVE

This study assesses radiation protection practices and knowledge among orthopedic surgeons in Saudi Arabia.

METHODS

This cross-sectional study surveyed orthopedic surgeons in Saudi Arabia using an online standardized and pre-tested questionnaire. The data were analyzed using statistical software.

RESULTS

The cross-sectional study was conducted among 102 participants. This survey revealed significant gaps in understanding safety protocols for radiation, as formal training in radiation protection was provided to only 3.9% of surgeons, whereas 7.8% had a basic awareness of the ALARA (as low as reasonably achievable) principle. Even though 67.6% of respondents reported the regular use of lead aprons, other radiation protective equipment, such as leaded eyeglasses and thyroid shields, was less frequently or rarely used; moreover, 80.4% of participants did not use dosimeters to monitor their radiation dose.

CONCLUSION

The findings of the study comply with the global trends that may be traced in the investigations of other studies where inconsistent use of protective equipment and a lack of corresponding knowledge were prevalent. The current investigation accentuates the importance of mandatory radiation safety training and regular monitoring of the enforcement of protective equipment use; moreover, prioritizing these measures can protect surgeons from the enduring risks of radiation exposure, such as cataracts, cancer, and other radiation-induced disorders.

Is Ocular Safety in Orthopaedics Overlooked? A Systematic Review of Annual Ocular Radiation Exposure and Protective Measures

BACKGROUND

Intraoperative fluoroscopy is increasingly common in orthopaedics, although recent guidelines have reduced the maximum recommended exposure to 20 mSv annually. A systematic review of the literature was conducted to comprehensively assess current adherence to exposure guidelines, identify practice settings at increased risk for exposure, and determine the best practices and personal protective equipment for ocular radiation risk mitigation.

QUESTIONS/PURPOSES

In this systematic review we asked: (1) Is the annual amount of eye irradiation received by orthopaedic surgeons below the recommended limit of 20 mSv? (2) What is the effectiveness of leaded glasses in reducing the eye's exposure to radiation? (3) Which imaging setups and operative techniques reduce ocular irradiation?

METHODS

PubMed, Medline, EBSCOhost, and Google Scholar were queried on September 28, 2023, to identify studies assessing intraoperative ocular radiation exposure among orthopaedic surgeons. Studies that measured radiation in or around the eye (such as the bridge of the nose or eyebrows) during orthopaedic procedures were included. Exclusion criteria were duplicate studies, studies that only estimated eye radiation based on the radiation dose recorded at parts of the body distant from the eyes, nonoriginal research, case reports, and articles without full-text English versions available. A total of 393 unique articles were retrieved, and after title, abstract, and full-text screening, 23 dosimetry studies were included, comprising 12 prospective observational studies, 7 phantom models, 1 cadaver model, 2 observational studies, and 1 randomized control trial. Risk of bias was determined via the Methodological Index for Nonrandomized Studies (MINORS) tool. Study quality was generally good to excellent, with noncomparative studies having a mean MINORS score of 14 ± 0 of 16 and comparative studies achieving a mean score of 19 ± 1 of 24, with higher scores representing better study quality. Due to extensive heterogeneity in study design, a meta-analysis was not conducted, with the results rather presented as a narrative summary of key findings.

RESULTS

The vast majority of surgeons conducting a variety of orthopaedic and traumatologic procedures were not exposed to a hazardous level of eye irradiation annually, but surgeons who perform a high volume of fluoroscopy-intensive procedures may exceed guidelines. Leaded eyeglasses reduced eye radiation by about 90%, with sport wrap-around glasses offering better shielding than alternatives, although leaded glasses overall were largely underutilized. Positioning mini C-arms in the standard vertical configuration was shown to provide up to a 13-fold decrease in radiation exposure compared with inverted configuration, while standing perpendicular to the fluoroscope further reduced eye irradiation.

CONCLUSION

We found that orthopaedic surgeons who perform a high volume of fluoroscopy-intensive procedures may be at risk of exceeding recommendations on annual radiation exposure, although exposure can be mitigated through various simple strategies. In particular, this analysis found that the use of sport wrap-around leaded glasses, positioning of mini-C arms in the standard vertical configuration, and standing perpendicular to the fluoroscope provide the most effective means of limiting ocular radiation exposure. As ophthalmic radiation exposure presents a potentially important occupational health hazard to orthopaedic surgeons, further investigations of radiation exposure specific to high-volume, fluoroscopy-intensive orthopaedic practices and long-term ophthalmic outcomes will help determine the extent of the potential harm posed by frequent exposure to intraoperative radiation over the span of a career.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Bibliometric analysis of occupational exposure in operating room from 1973 to 2022

OBJECTIVE

The purpose of this study is to identify and visualize from different perspectives the topic on occupational exposure in operating room (OEOR).

METHODS

In the Web of Science Core Collection (WoSCC), all the half-century data were retrieved from January 1st, 1973 to December 31st, 2022. CiteSpace, VOSviewer and Excel 2019 were employed to analyze and visualize data, based on publications, countries, institutions, journals, authors, keywords.

RESULT

A total of 336 journal papers were found. The increase of publications virtually started in 1991, peaked in 2020 and has been slowing down ever since. USA played most significant part among all the 49 countries/regions, while Universidade Estadual Paulista out of 499 institutions published the most papers. International Archives of Occupational and Environmental Health bears the most documents and citations in all the 219 retrieved journals. There are 1847 authors found, among whom Hoerauf K is the most influential one. "Occupational exposure", "nitrous oxide" and "operating room personnel" are the top 3 co-occurrences keywords.

CONCLUSION

The trend in the field lies in "anaesthetic gas", "blood borne pathogen", "radiation" and "aerosol", while "surgical smoke" and "occupational safety" are the recently researching hot spots in this study. Accurate recognize and effective protection are always essential subjects for researchers.

Quantifying Radiation Exposure in Minimally Invasive Spinal Surgery: A Single-Surgeon Study of Minimally Invasive Surgery-Oblique Lateral Lumbar Interbody Fusion (MIS-OLLIF) With Double C-Arm Technique

In the advancement of spinal surgery, minimally invasive techniques such as the oblique lateral lumbar interbody fusion (OLLIF) have emerged, offering improved clinical outcomes and the use of dual C-Arm intraoperative imaging. Despite the benefits, the radiation exposure to surgeons and staff from this dual-source imaging has not been thoroughly examined. This study aims to quantify the radiation exposure received by surgeons during OLLIF procedures, filling a gap in current research that primarily focuses on single-source imaging. Over 12 months, radiation doses were measured across 121 surgeries at four locations. Data analysis included average radiation exposure per surgery and variations across surgical sites. The findings showed an average radiation emission of 198.78 mGy per OLLIF surgery, with the surgeon receiving approximately 0.06 mSv per surgery. Cumulative doses for the surgeon were below the safety thresholds set by European and American standards. The significance of these findings lies in their contribution to the understanding of occupational safety in spinal surgery. The results indicate that with proper protective measures, such as lead aprons, the radiation exposure from the OLLIF technique is manageable within occupational limits. This study highlights the importance of monitoring radiation exposure and may influence the development of new guidelines and protective strategies in the field. Future research could expand the cohort of surgeons to validate these findings, develop new protective strategies, and explore radiation exposure in more complex multi-level fusions.

Evaluation of Leg Length Difference on Perioperative Radiographs of Total Hip Arthroplasty Considering Lower Limb Malposition

BACKGROUND

During total hip arthroplasty (THA) in lateral decubitus, perioperative radiography allows the surgeon a simple evaluation of the leg length difference (LLD) by measuring the proximal femoral length. However, the effect of femoral malpositioning on proximal femoral length measurements during the evaluation of perioperative radiographs is not adequately understood. We aimed to (1) investigate the effects of malposition on proximal femoral length using three-dimensional computer simulations and (2) verify whether a simple correction formula can improve the accuracy of LLD evaluation on perioperative radiographs.

METHODS

We analyzed 86 patients who underwent THA. Digitally reconstructed radiography (DRR) images were reconstructed in various limb positions (femoral abduction, adduction, and flexion), and proximal femoral length measurements in those malpositions were simulated. Additional morphological measurements of the femoral neck torsion angle in the sagittal plane were performed to elucidate the simulation findings. The malposition angle of abduction-adduction was evaluated with actual perioperative radiographs, and trigonometric correction was attempted.

RESULTS

The leg length measurement decreased as the femoral DRR image shifted from neutral to abduction and adduction, demonstrating approximately 1 mm per 10° of abduction or adduction. The leg length measurement increased as the femoral image shifted from neutral to 10° and 20° of flexion, demonstrating approximately 3 mm per 10° of flexion. With a peak at 20° of flexion, the proximal femoral length measurement decreased in the DRR images at 30°, 40°, 50° and 60° of flexion. The femoral neck torsion angle was 21.1 ± 5.6° on the operative side. The effect of coronal malposition on leg length discrepancy was so small that the difference following trigonometric correction was not statistically significant (p=0.108).

CONCLUSION

In the present simulation, coronal malposition had a small effect on LLD evaluation. As the femoral neck has a torsion of approximately 20°, the proximal femoral length is projected the longest when the femur is flexed 20°. With careful positioning of the limb in the coronal plane, the use of a correction formula for LLD evaluation would not be necessary. Surgeons should ensure that both lower limbs are in the same position in the sagittal plane during THA in lateral decubitus.

Intraoperative MRI: A Review of Applications Across Neurosurgical Specialties

Intraoperative MRI (iMRI) made its debut to great fanfare in the mid-1990s. However, the enthusiasm for this technology with seemingly obvious benefits for neurosurgeons has waned. We review the benefits and utility of iMRI across the field of neurosurgery and present an overview of the evidence for iMRI for multiple neurosurgical disciplines: tumor, skull base, vascular, pediatric, functional, and spine. Publications on iMRI have steadily increased since 1996, plateauing with approximately 52 publications per year since 2011. Tumor surgery, especially glioma surgery, has the most evidence for the use of iMRI contributing more than 50% of all iMRI publications, with increased rates of gross total resection in both adults and children, providing a potential survival benefit. Across multiple neurosurgical disciplines, the ability to use a multitude of unique sequences (diffusion tract imaging, diffusion-weighted imaging, magnetic resonance angiography, blood oxygenation level-dependent) allows for specialization of imaging for various types of surgery. Generally, iMRI allows for consideration of anatomic changes and real-time feedback on surgical outcomes such as extent of resection and instrument (screw, lead, electrode) placement. However, implementation of iMRI is limited by cost and feasibility, including the need for installation, shielding, and compatible tools. Evidence for iMRI use varies greatly by specialty, with the most evidence for tumor, vascular, and pediatric neurosurgery. The benefits of real-time anatomic imaging, a lack of radiation, and evaluation of surgical outcomes are limited by the cost and difficulty of iMRI integration. Nonetheless, the ability to ensure patients are provided by a maximal yet safe treatment that specifically accounts for their own anatomy and highlights why iMRI is a valuable and underutilized tool across multiple neurosurgical subspecialties.

Navigation and Robotic Single-Position Prone LLIF: First Cases in Brazil

OBJECTIVE

has been rapid technological advancement in navigation-guided minimally invasive surgery over the past two decades, making these advancements an invaluable aid for surgeons by essentially providing real-time virtual reconstruction of patient anatomy. The objectives of these navigation- and robot-guided procedures are to reduce the likelihood of neural and vascular injury, minimize hospitalization time, decrease bleeding and postoperative pain, shorten healing time, and lower infection rates.

METHODS

A unicentric, retrospective cohort study was conducted to evaluate the preoperative and postoperative clinical and radiographic outcomes of the first Latin American patients diagnosed with lumbar degenerative disease who underwent lumbar interbody fusion at the L4-L5 level via prone-position lateral lumbar interbody fusion-single position prone access.

RESULTS

A total of 80 patients (40 assisted by fluoroscopy, 40 assisted by robotics) with 320 percutaneous pedicle screws were evaluated. The primary outcomes analyzed and compared were radiation exposure per screw (seconds), skin-to-skin operative time (minutes), and recovery time (days). Secondary outcomes included lumbar pain intensity (visual analog scale), reported functional disability (Oswestry Disability Index), and any potential complications. All secondary outcomes were collected at the postoperative time.

CONCLUSION

Comparing minimally invasive spine interventions with free-hand instrumentation and robotic instrumentation, a statistically significant difference was identified in radiation exposure per screw and surgical time. The literature on Cirq Robotic is limited; however, minimally invasive spine surgery with robotic assistance appears advantageous in terms of radiation exposure and surgical time.

The Impact of Navigation in Lumbar Spine Surgery: A Study of Historical Aspects, Current Techniques and Future Directions

Background/Objectives: We sought to improve accuracy while minimizing radiation hazards, improving surgical outcomes, and preventing potential complications. Despite the increasing popularity of these systems, a limited number of papers have been published addressing the historical evolution, detailing the areas of use, and discussing the advantages and disadvantages, of this increasingly popular system in lumbar spine surgery. Our objective was to offer readers a concise overview of navigation system history in lumbar spine surgeries, the techniques involved, the advantages and disadvantages, and suggestions for future enhancements to the system. Methods: A comprehensive review of the literature was conducted, focusing on the development and implementation of navigation systems in lumbar spine surgeries. Our sources include PubMed-indexed peer-reviewed journals, clinical trial data, and case studies involving technologies such as computer-assisted surgery (CAS), image-guided surgery (IGS), and robotic-assisted systems. Results: To develop more practical, effective, and accurate navigation techniques for spine surgery, consistent advancements have been made over the past four decades. This technological progress began in the late 20th century and has since encompassed image-guided surgery, intraoperative imaging, advanced navigation combined with robotic assistance, and artificial intelligence. These technological advancements have significantly improved the accuracy of implant placement, reducing the risk of misplacement and related complications. Navigation has also been found to be particularly useful in tumor resection and minimally invasive surgery (MIS), where conventional anatomic landmarks are lacking or, in the case of MIS, not visible. Additionally, these innovations have led to shorter operative times, decreased radiation exposure for patients and surgical teams, and lower rates of reoperation. As navigation technology continues to evolve, future innovations are anticipated to further enhance the capabilities and accessibility of these systems, ultimately leading to improved patient outcomes in lumbar spine surgery. Conclusions: The initial limited utilization of navigation system in spine surgery has further expanded to encompass almost all fields of lumbar spine surgeries. As the cost-effectiveness and number of trained surgeons improve, a wider use of the system will be ensured so that the navigation system will be an indispensable tool in lumbar spine surgery. However, continued research and development, along with training programs for surgeons, are essential to fully realize the potential of these technologies in clinical practice.

New Ultrasound-Guided Approach to Access to the Posterolateral Part of Intervertebral Lumbar Discs: A Cadaveric Study

Background: Approximately 40% of chronic low back pain patients have a discogenic origin. In relation to intervertebral disc injuries, most of them are in the posterior and lateral zone of the disc, involving the anterior lumbar roots and the spinal cord. Objective: The objective was to analyze and describe the accuracy and safety of a new ultrasound-guided approach to target the posterolateral part of the intervertebral lumbar discs in cadaveric specimens. Methods: A cross-anatomical study on sixty cadaver intervertebral lumbar discs was performed. A needle was introduced in the posterolateral part of the discs using ultrasound guidance. A transducer was placed in the anterior abdomen to visualize the discs in cross-section as well. A dissection of the specimen was performed to visualize the final position of the needle tip and its distance from the main lumbar structures. The angulation, length, and distance of the needle from the vertebral spine, the relevant ultrasound anatomical references, and the accuracy of the procedure were evaluated. Results: The needle tip reached the posterolateral part of the discs in 93.3% of the attempts. The mean length of the needle inserted was 79 ± 15 mm, the angulation 129 ± 20.2°, the distance from the spinous process was 77 ± 19 mm, and the distance of the needle to the nerve roots was 2.0 ± 1.2 mm. No statistically significant differences between genders were found. Conclusions: An ultrasound-guided technique can be an accurate and safe technique to perform invasive procedures on the posterolateral part of the intervertebral lumbar discs.

Accuracy of Ultrasound-Guided Needle Placement on the L5 Lumbar Nerve Root: A Cadaveric Study

OBJECTIVES

The aims of the study are to analyze and describe the accuracy of an ultrasound-guided approach to target the L5 root in cadaveric specimens and evaluate whether gender differences exist.

DESIGN

A cross-anatomical study on 40 cadaver L5 nerve roots was performed. A needle was introduced until contacting the L5 nerve root using ultrasound guidance. After that, specimens were frozen and studied by a cross-anatomical view to see the needle's path. The angulation, length, distance from the vertebral spine, the relevant ultrasound anatomical references, and the accuracy of the procedure were evaluated.

RESULTS

The needle tip reached the L5 root at a 72.5% rate. The mean angulation degrees of the needle relative to the skin surface were 75.53 ± 10.17 degrees, the length of the needle inserted was 5.83 ± 0.82 cm, and the distance from the vertebral spine to the point of entry of the needle was 5.39 ± 1.44 cm.

CONCLUSIONS

An ultrasound-guided technique can potentially be an accurate technique to perform invasive procedures on the L5 root. There were statistically significant differences between males and females in the length of the needle introduced. If the L5 root is not clearly visualized, ultrasound will not be the technique of choice.

Comparison of Radiation Exposure for Pregnant Patients Requiring Intervention for Suspected Obstructing Nephrolithiasis

OBJECTIVE

To identify the differences in radiation exposure per suspected stone episode between percutaneous nephrostomy tube (PCN), stent, and primary ureteroscopy (URS).The incidence of nephrolithiasis in pregnancy is low; however, repercussions for both mother and fetus can be significant. In cases of suspected obstructing nephrolithiasis, intervention may be required, including ureteral stent, PCN, or URS, with the potential for multiple subsequent procedures that often utilize fluoroscopy.

METHODS

Pregnant patients who required an intervention (stent, PCN, or URS) for suspected obstructing nephrolithiasis were retrospectively reviewed. The primary outcome was total fluoroscopy exposure per suspected stone episode. Secondary outcomes included fluoroscopic exposure per procedure and number of procedures required.

RESULTS

After excluding patients with renal anomalies and incomplete radiation data, 78 out of 100 patients were included in the analysis. Forty patients (51.3%) underwent initial stent placement, 22 (28.2%) underwent initial PCN placement, and 16 (20.5%) underwent primary URS. Total mean radiation exposure per stone episode was significantly higher in patients who underwent PCN, (286.9 mGy vs 3.7 mGy (stent) and 0.2 mGy (URS), P <.001). In addition, patients who underwent initial PCN placement had significantly more procedures (P <.001) and mean radiation exposure per procedure was higher (P <.001). More than 40% of PCNs experienced dysfunction, and mean duration between PCN exchanges was 16.5 days.

CONCLUSION

In pregnant patients with suspected obstructing nephrolithiasis requiring intervention, initial PCN placement was associated with a significantly higher number of procedures, radiation exposure per procedure, and total radiation exposure per suspected stone episode compared to stent and URS.

Assessing Procedural Accuracy in Lateral Spine Surgery: A Retrospective Analysis of Percutaneous Pedicle Screw Placement with Intraoperative CT Navigation

Percutaneous pedicle screws (PPSs) are commonly used in posterior spinal fusion to treat spine conditions such as trauma, tumors, and degenerative diseases. Precise PPS placement is essential in preventing neurological complications and improving patient outcomes. Recent studies have suggested that intraoperative computed tomography (CT) navigation can reduce the dependence on extensive surgical expertise for achieving accurate PPS placement. However, more comprehensive documentation is needed regarding the procedural accuracy of lateral spine surgery (LSS). In this retrospective study, we investigated patients who underwent posterior instrumentation with PPSs in the thoracic to lumbar spine, utilizing an intraoperative CT navigation system, between April 2019 and September 2023. The system's methodology involved real-time CT-based guidance during PPS placement, ensuring precision. Our study included 170 patients (151 undergoing LLIF procedures and 19 trauma patients), resulting in 836 PPS placements. The overall PPS deviation rate, assessed using the Ravi scale, was 2.5%, with a notably higher incidence of deviations observed in the thoracic spine (7.4%) compared to the lumbar spine (1.9%). Interestingly, we found no statistically significant difference in screw deviation rates between upside and downside PPS placements. Regarding perioperative complications, three patients experienced issues related to intraoperative CT navigation. The observed higher rate of inaccuracies in the thoracic spine suggests that various factors may contribute to these differences in accuracy, including screw size and anatomical variations. Further research is required to refine PPS insertion techniques, particularly in the context of LSS. In conclusion, this retrospective study sheds light on the challenges associated with achieving precise PPS placement in the lateral decubitus position, with a significantly higher deviation rate observed in the thoracic spine compared to the lumbar spine. This study emphasizes the need for ongoing research to improve PPS insertion techniques, leading to enhanced patient outcomes in spine surgery.

Is navigation beneficial for transforaminal endoscopic lumbar foraminotomy? A preliminary comparison study with fluoroscopic guidance

PURPOSE

The primary purpose of this study was to determine radiation exposure of the surgeon during transforaminal endoscopic lumbar foraminotomy (TELF). Secondary purpose of this study was to compare clinical and radiologic outcomes between TELF under C-arm fluoroscopic guidance (C-TELF) and O-arm navigation-guided TELF (O-TELF).

METHODS

The author reviewed patients' medical records who underwent TELF at our institute from June 2015 to November 2022. A total of 40 patients were included (18 patients with C-TELF and 22 with O-TELF). Basic demographic data were collected. Preoperative/postoperative visual analog scale (VAS) and Oswestry Disability Index (ODI) were recorded at the outpatient clinic. Radiologic features were compared on X-rays at each follow-up. The degree of foraminal expansion was measured/compared through MRI. In the C-TELF group, the amount of exposure was calculated with a dosimeter.

RESULTS

Average surgeon's effective dose in the C-TELF group was 0.036 mSv. In the case of the O-TELF group, there was no radiation exposure during operation. However, the operation time in the O-TELF group was about 37 min longer than that in the C-TELF group. There were significant improvements in VAS/ODI after operation in both groups. Complications were identified in three patients.

CONCLUSION

O-TELF showed similarly favorable clinical and radiologic outcomes to C-TELF in lumbar foraminal stenosis, including complication rate. Compared to C-TELF, O-TELF has an advantage of not wearing a lead apron since the operator is not exposed to radiation. However, the operation time was longer with O-TELF due to O-arm setting time. Because there are pros and cons, the choice of surgical method depends on the surgeon's preference.

Intraoperative Fluoroscopy Radiation Using OEC 9900 Elite C-arm: Risk and Method for Decreasing Exposure

ABSTRACT

The use of intraoperative fluoroscopy in surgery produces scattered radiation that can expose all operating room personnel to measurable and, in some cases, substantial radiation doses. The goal of this work is to assess and document potential radiation doses to various staff positions in a simulated standard operating room environment. Adult-sized mannequins wearing standard lead protective aprons were placed at seven positions around large and small BMI cadavers. Doses were recorded in real time at thyroid level with Bluetooth-enabled dosimeters for a variety of fluoroscope settings and imaging views. A total of 320 images were acquired, resulting in 2,240 dosimeter readings from the seven mannequins. Doses were compared to cumulative air kerma (CAK) calculations provided by the fluoroscope. There was a strong correlation between the CAK and the recorded scattered radiation doses ( P < 0.001). Radiation doses could be reduced by manipulating C-arm manual technique settings [e.g., turning off the automatic exposure control (AEC) and using pulse (PULSE) or low dose (LD) settings]. Staff position and patient size also affected the recorded doses. The highest radiation doses were recorded across all settings for the mannequin positioned immediately adjacent to the C-arm x-ray tube. The larger BMI cadaver generated greater scattered radiation than the smaller BMI cadaver for all views and settings. This work provides suggestions for reducing exposure to operating room personnel beyond standard techniques of reducing beam-on time, increasing the distance from the radiation source, and use of shielding. Simple changes in C-arm settings (turning AEC off, avoiding DS setting, use of PULSE or LD settings) can markedly reduce dose to staff.

Minimizing Surgeon Radiation Exposure During Operative Treatment of Pediatric Supracondylar Humerus Fractures

BACKGROUND

Orthopaedic surgeons are exposed to high levels of radiation, which may lead to higher rates of cancer among orthopaedic surgeons. There are a series of techniques currently practiced to pin supracondylar humerus fractures including pinning the arm on the C-arm itself, using a plexiglass rectangle or a graphite floating arm board; however, the variation in radiation exposure to the surgeon is unknown. We aimed to determine how the position of the C-arm affects radiation exposure to the surgeon during the treatment of a pediatric supracondylar humerus fracture.

MATERIAL AND METHODS

A simulated operating room was created to simulate a closed reduction and percutaneous pinning of a supracondylar humerus fracture. A phantom model was used to simulate the patient's arm. We assessed performing the procedure with the arm on plexiglass, graphite, or on top of the C-arm image receptor. The C-arm was positioned either with the source down and image receptor up (standard position) or with the source up and image receptor down (inverted position). Radiation exposure was recorded from levels corresponding to the surgeon's head, midline, and groin. The estimated effective dose equivalent was calculated to account for the varying radiation sensitivity of different organs.

RESULTS

We found the effective dose equivalent, or the overall body damage from radiation, was 5.4 to 7.8% higher than the surgeon when the C-arm was in the inverted position (source up, image receptor down). We did not find any differences in radiation exposure to the surgeon when the arm was supported on plexiglass versus graphite.

CONCLUSION

The C-arm positioned in the standard fashion exposes the surgeon to less damaging radiation. Therefore, when the surgeon is standing, we recommend using the C-arm in the standard position.

CLINICAL RELEVANCE

Orthopaedic surgeons who stand should use the C-arm in the standard position to pin supracondylar humerus fractures to lower the risk of ionizing radiation exposure.

Ultrasound-guided Jamshidi needle puncture to reduce radiation exposure during percutaneous pedicle screw placement: study protocol for a randomised controlled trial

INTRODUCTION

Percutaneous pedicle screw placement (PPSP) is a minimally invasive procedure highly dependent on fluoroscopic guidance, which results in increased radiation exposure and prolonged operative time. Ultrasound can image the lumbar paravertebral anatomy and the needle trajectory in real time, which may help reduce the use of fluoroscopy and radiation dose in PPSP. We will conduct a parallel randomised controlled trial to mainly investigate the effect of ultrasound guidance in radiation reduction during PPSP.

METHODS AND ANALYSIS

A total of 42 patients will be recruited and randomly assigned to the intervention group and the control group at a 1:1 ratio. In the intervention group, we will use ultrasound in combination with fluoroscopy to guide the insertion of the Jamshidi needles. In the control group, PPSP will be performed under conventional fluoroscopic guidance. The primary outcomes are the cumulative fluoroscopy time (s), radiation dose (mGy) and exposure times of screw placement. The secondary outcomes are insertion time of guidewire, rate of pedicle perforation, rate of facet joint violation, visual analogue scale for back pain, Oswestry Disability Index and complications. The participants, outcome assessors and data analysts will be blinded to allocation.

ETHICS AND DISSEMINATION

The trial was approved by the research ethics committee of Shengjing Hospital, China Medical University. The results will be presented at academic seminars and submitted for publication in peer-reviewed journals.This study involves human participants and was approved by Research Ethics Committee of Shengjing Hospital, China Medical University reference number：2022PS704K. Participants gave informed consent to participate in the study before taking part.

TRIAL REGISTRATION NUMBER

ChiCTR2200057131.

Side-firing intraoperative ultrasound applied to resection of pituitary macroadenomas and giant adenomas: A single-center retrospective case-control study

Introduction

Multiple intraoperative navigation and imaging modalities are currently available as an adjunct to endoscopic transsphenoidal resection of pituitary adenomas, including intraoperative CT and MRI, fluorescence guidance, and neuronavigation. However, these imaging techniques have several limitations, including intraoperative tissue shift, lack of availability in some centers, and the increased cost and time associated with their use. The side-firing intraoperative ultrasound (IOUS) probe is a relatively new technology in endoscopic endonasal surgery that may help overcome these obstacles.

Methods

A retrospective analysis was performed on patients admitted for resection of pituitary adenomas by a single surgeon at the University of Mississippi Medical Center. The control (non-ultrasound) group consisted of twelve (n=12) patients who received surgery without IOUS guidance, and the IOUS group was composed of fifteen (n=15) patients who underwent IOUS-guided surgery. Outcome measures used to assess the side-firing IOUS were the extent of tumor resection, postoperative complications, length of hospital stay (LOS) in days, operative time, and self-reported surgeon confidence in estimating the extent of resection intraoperatively.

Results

Preoperative data analysis showed no significant differences in patient demographics or presenting symptoms between the two groups. Postoperative data revealed no significant difference in the rate of gross total resection between the groups (p = 0.716). Compared to the non-US group, surgeon confidence was significantly higher (p < 0.001), and operative time was significantly lower for the US group in univariate analysis (p = 0.011). Multivariate analysis accounting for tumor size, surgeon confidence, and operative time confirmed these findings. Interestingly, we noted a trend for a lower incidence of postoperative diabetes insipidus in the US group, although this did not quite reach our threshold for statistical significance.

Conclusion

Incorporating IOUS as an aid for endonasal resection of pituitary adenomas provides real-time image guidance that increases surgeon confidence in intraoperative assessment of the extent of resection and decreases operative time without posing additional risk to the patient. Additionally, we identified a trend for reduced diabetes insipidus with IOUS.

Percutaneous thoraco-lumbar-sacral pedicle screw placement accuracy results from a multi-center, prospective clinical study using a skin marker-based optical navigation system

STUDY DESIGN

Prospective multi-center study.

OBJECTIVE

The study aimed to evaluate the accuracy of pedicle screw placement using a skin marker-based optical surgical navigation system for minimal invasive thoraco-lumbar-sacral pedicle screw placement.

METHODS

The study was performed in a hybrid Operating Room with a video camera-based navigation system integrated in the imaging hardware. The patient was tracked with non-invasive skin markers while the instrument tracking was via an on-shaft optical marker pattern. The screw placement accuracy assessment was performed by three independent reviewers, using the Gertzbein grading. The screw placement time as well as the staff and patient radiation doses was also measured.

RESULTS

In total, 211 screws in 39 patients were analyzed for screw placement accuracy. Of these 32.7% were in the thoracic region, 59.7% were in the lumbar region, and 7.6% were in the sacral region. An overall accuracy of 98.1% was achieved. No screws were deemed severely misplaced (Gertzbein grading 3). The average time for screw placement was 6 min and 25 secs (± 3 min 33 secs). The average operator radiation dose per subject was 40.3 µSv. The mean patient effective dose (ED) was 11.94 mSv.

CONCLUSION

Skin marker-based ON can be used to achieve very accurate thoracolumbarsacral pedicle screw placements.

Two-dimensional fluoroscopy-guided robot-assisted percutaneous endoscopic transforaminal discectomy: a retrospective cohort study

Percutaneous Endoscopic Transforaminal Discectomy (PETD) has been widely used for minimally invasive treatment of lumbar disc herniation (LDH), and percutaneous disc target puncture has a steep learning curve and high radiation exposure. Proper technology grafting can improve the surgical procedure and clinical outcomes. The changes brought by grafting surgical robots into PETD are worth investigating. A retrospective analysis was performed on the information of patients who received PETD in our hospital from March 2019 to July 2020. A total of 102 of patients who received 2D-guided robot-assisted PETD were included in Group A, and 102 of patients who received C-arm fluoroscopy-guided bare-handed PETD were included in Group B. The number of punctures, number of fluoroscopies, operation duration, intraoperative anxiety score, complications, and visual analogue scale (VAS) score and Oswestry disability index (ODI) before operation, on Day 1 after operation and at the last follow-up visit of the two groups were compared. All 204 patients received successful operations. Group A received 1.20±0.42 punctures, 10.49±2.16 fluoroscopies and 60.69±5.63 minutes of operation, significantly fewer than the 4.84±1.94 punctures, 17.41±3.23 fluoroscopies and 71.19±5.11 minutes of operation of Group B (all P<0.05), and Group A had significantly lower intraoperative anxiety scores and incidence of complications than Group B (both P<0.05). Both groups had comparable VAS and ODI scores on Day 1 after operation and at the last follow-up visit, which were both significantly higher than those before operation (P<0.05). 2D-guided robot-assisted PETD can enable precise planning of the puncture path, make it easier for operators to complete targeted punctures at pathogenic targets, reduce the number of punctures and fluoroscopies, shorten the operation duration to optimize the operation process, and reduce complications and alleviate intraoperative anxiety for better clinical results. Therefore it mayb be a better choice to assist PETD.