Measurements of surgeons' exposure to ionizing radiation dose during intraoperative use of C-arm fluoroscopy

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.

Simulation-based Flexible Needle Control with Single-core FBG Feedback for Spinal Injections

Objective

We present a general framework of simultaneous needle shape reconstruction and control input generation for robot-assisted spinal injection procedures, without continuous imaging feedback.

Methods

System input-output mapping is generated with a real-time needle-tissue interaction simulation, and single-core FBG sensor readings are used as local needle shape feedback within the same simulation framework. FBG wavelength shifts due to temperature variation is removed by exploiting redundancy in fiber arrangement.

Results

Targeting experiments performed on both plastisol lumbar phantoms as well as an ex vivo porcine lumbar section achieved in-plane tip errors of 0.6 ± 0.3 mm and 1.6 ± 0.9 mm , and total tip errors of 0.9 ± 0.7 mm and 2.1 ± 0.8 mm for the two testing environments.

Significance

Our clinically inspired control strategy and workflow is self-contained and not dependent on the modality of imaging guidance. The generalizability of the proposed approach can be applied to other needle-based interventions where medical imaging cannot be reliably utilized as part of a closed-loop control system for needle guidance.

A Human-Scale Clinically Ready Electromagnetic Navigation System for Magnetically Responsive Biomaterials and Medical Devices

Magnetic navigation systems are used to precisely manipulate magnetically responsive materials enabling the realization of new minimally invasive procedures using magnetic medical devices. Their widespread applicability has been constrained by high infrastructure demands and costs. The study reports on a portable electromagnetic navigation system, the Navion, which is capable of generating a large magnetic field over a large workspace. The system is easy to install in hospital operating rooms and transportable through health care facilities, aiding in the widespread adoption of magnetically responsive medical devices. First, the design and implementation approach for the system are introduced and its performance is characterized. Next, in vitro navigation of different microrobot structures is demonstrated using magnetic field gradients and rotating magnetic fields. Spherical permanent magnets, electroplated cylindrical microrobots, microparticle swarms, and magnetic composite bacteria-inspired helical structures are investigated. The navigation of magnetic catheters is also demonstrated in two challenging endovascular tasks: 1) an angiography procedure and 2) deep navigation within the circle of Willis. Catheter navigation is demonstrated in a porcine model in vivo to perform an angiography under magnetic guidance.

Knowledge, Attitude, and Practices Regarding Radiation and its Hazards Among Orthopaedic Surgeons in India: A Questionnaire-Based Study

Introduction

Orthopaedic surgeons are among the most frequent users of radiation and are often exposed to X-Ray radiation regularly. There is an overall unsatisfactory level of knowledge, attitude, and practices regarding the same among surgeons. This study aimed to assess the practices among orthopaedic surgeons regarding radiation and its hazards in India.

Methodology

This questionnaire-based survey was conducted between March and September 2022. The questionnaire broadly assessed the knowledge, awareness, and practices among orthopaedic surgeons regularly exposed to X-ray radiation. The questionnaire consisted of objective and Likert scale questions which were distributed to the respondents electronically using publicly available contact information. A qualitative review of interpretations obtained from the responses and available evidence in the literature was then performed.

Results

The response rate for the survey was 36.4%. 65.9% reported using trunk protection all the time during procedures. 57.1% of respondents reported not using thyroid protection during procedures. 92.3% reported not using protective goggles and 100% did not use appropriate gloves. 76.9% were not issued dosimeters, and only 5.5% of those who had been issued one wore it during radiation procedures. 58.2% reported having a dedicated employee to operate the machine. 86.8% of respondents did not have formal training and 81.3% were not aware of institutes offering formal training.

Conclusion

There is very high compliance with the use of protection aprons among the respondents however, the use of other apparel like thyroid shields, protection goggles and gloves was poor. The awareness regarding radiation exposure was also poor as most respondents were not issued dosimeters, however, those issued with one were well aware of their exposure. It is imperative to prioritize both surgeons' and patients' safety where radiation exposure is concerned.

[Mobile C-arm-Radiation exposure and workflow killer? : Potential of an innovative assistance system for intraoperative positioning]

Despite its versatile applicability the intraoperative use of a mobile C‑arm is often problematic and potentially associated with increased radiation exposure for both the patient and the personnel. In particular, the correct positioning for adequate imaging can become a problem as the nonsterile circulating nurse has to coordinate the various maneuvers together with the surgeon without having a good view of the surgical field. The sluggishness of the equipment and the intraoperative setting (sterile borders, additional hardware, etc.) pose further challenges. A light detection and ranging (LIDAR)-based assistance system shows promise to provide accurate and intuitive repositioning support as part of an initial series of experimental trials. For this purpose, the sensors are attached to the C‑arm base unit and enable navigation of the device in the operating room to a stored target position using a simultaneous localization and mapping (SLAM) algorithm. An improvement of the workflow as well as a reduction of radiation exposure represent the possible potential of this system. The advantages over other experimental approaches are the lack of external hardware and the ease of use without isolating the operator from the rest of the operating room environment; however, the suitability for daily use in the presence of additional interfering factors should be verified in further studies.

Radiation exposure doses to the surgical team during hip surgery is significantly higher during lateral imaging than posteroanterior imaging: a cadaveric simulation study

BACKGROUND

Fluoroscopy is indispensable when determining appropriate and effective interventions in orthopedic surgery. On the other hand, there is growing concern about the health hazards of occupational radiation exposure. The aim of this cadaveric simulation study was to measure radiation exposure doses to the surgical team during hip surgery.

METHODS

We reproduced the intraoperative setting of hip surgery using 7 fresh frozen cadavers (5 male, 2 female) to simulate patients and mannequins to simulate the surgeon, scrub nurse, and anesthesiologist. Six real-time dosimeters were mounted at sites corresponding to the optic lens, thyroid gland, chest, gonads, foot, and hand on each mannequin. The radiation exposure dose to each team member was measured during posteroanterior and lateral fluoroscopic imaging.

RESULTS

Radiation exposure doses to the surgeon were significantly higher during 3 min of lateral imaging than during 3 min of posteroanterior imaging at the optic lens (8.1 times higher), thyroid gland (10.3 times), chest (10.8 times), and hand (19.8 times) (p = 0.018, p = 0.018, p = 0.018, and p = 0.018, respectively). During lateral imaging, the radiation doses to the nurse were 0.16, 0.12, 0.09, 0.72, and 0.38 times those to the surgeon at the optic lens, thyroid, chest, gonads, and foot, respectively. The radiation dose to the anesthesiologist was zero at all anatomic sites during posteroanterior imaging and very small during lateral imaging.

CONCLUSIONS

Radiation exposure dose was significantly higher during lateral imaging up to 19.8 times comparing to the posteroanterior imaging. It is effective to reduce the lateral imaging time for reducing the intraoperative radiation exposure. In addition, appropriate distance from fluoroscopy resulted in very low exposure for nurses and anesthesiologists. Surgeon should pay attention that surgical staff do not get closer than necessary to the irradiation field.

Lateral access minimally invasive spine surgery in adult spinal deformity

Background

Oblique lumbar interbody fusion (OLIF) and percutaneous posterior approach for screw fixation (PPS) is the latest minimal invasive treatment for spinal deformity in adult patients (ASD). This study aims to design and highlight key points for ASD correction.

Materials and methods

We retrospectively analyzed 54 patients who had undergone OLIF with PPS for ASD from October 2019 to January 2022 (average 71.5 ± 6.2 years-old, male 4, female 50) with a mean follow-up period of 29.2 months. Clinical outcomes are expressed by values including the Oswestry disability index (ODI) and visual analogue scale (VAS) for back pain. The imagistic assessment was also performed preoperatively and at 12, and 24 months postoperatively. For OLIF51, CT- MRI fusion images were obtained before surgery.

Results

Postoperative ODI and VAS were 30.5 ± 18.9% and 31.2 ± 6.9 mm, respectively. The average operating time and blood loss during the surgical exposure was 490.9 ± 85.4 min and 1195.2 ± 653.8 ml. Preoperative SVA, PI-LL, and PT were 96.5 ± 55.9 mm, 39.3 ± 22.1°, 34.5 ± 11.0°, respectively. Postoperatively, SVA and PT became normal (24.1 ± 39.0 mm, 17.1 ± 10.3°) and PI-LL was ideal (2.4 ± 12.6°). Postoperative ODI and VAS were 30.5 ± 18.9% and 31.2 ± 6.9 mm. For OLIF51, the results revealed gain in L5-S1 lordosis and intervertebral disc height 9.4° and 4.2 mm respectively. The complications consisted of PJK in 21 cases (38.9%), rod breakage in 5 cases (9.3%), deep or superficial wound infection in 2 cases (3.7%).

Conclusion

Clinical and imagistic results of OLIF and PPS for ASD were excellent. The radiographic measurements revealed that OLIF51 created good L5-S1 lordosis and significant L5-S1 disc height. CT-MRI fusion images were very useful for evaluating vascular anatomy for OLIF51.

Enhancing Radiation Safety Culture: Investigating the Mediating Role of Awareness Among Orthopedic Doctors and Operation Theatre Assistants

INTRODUCTION

The increasing use of minimally invasive orthopedic procedures has led to a greater reliance on fluoroscopy, resulting in elevated radiation exposure for surgeons. This study aimed to evaluate the knowledge, awareness, and daily practices of orthopedic surgeons regarding radiation safety in an academic hospital. Understanding radiation safety is crucial to minimize patient exposure and prevent adverse effects on surgeons.

METHODS

This cross-sectional study was conducted at the Department of Orthopedics of different tertiary care hospitals in Rawalpindi, Pakistan. Data were collected prospectively for two years, and a total of 505 participants, including residents, consultants, and operation theatre assistants, completed a questionnaire. The questionnaire was validated by experts and covered information on fluoroscopy usage, frequency of surgeries, awareness of radiation safety, and protective measures. Ethical approval was obtained, and data were analyzed using SPSS version 26.0.

RESULTS

The majority of participants were male (74.1%), and the sample included various ranks of orthopedic surgeons. Only 56.2% of participants were aware of the usage of fluoroscopy, and 40.2% had read some research on the topic. While 44.6% used lead aprons for radiation protection, the usage of other protective measures and dosimeters was limited. The mediation analysis showed an insignificant indirect association between the rank of orthopedic surgeons, number of surgeries performed, and fluoroscopy usage as a mediator. Awareness and reading research on fluoroscopy were significantly associated with radiation protection.

CONCLUSION

The knowledge, awareness, and daily practices of orthopedic surgeons regarding radiation safety in fluoroscopy use need improvement. The findings emphasize the importance of implementing training programs, providing radiation protection devices, and ensuring compliance with safety guidelines.

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.

In Situ Flexible Needle Adjustment Towards MRI-Guided Spinal Injections Based on Finite Element Simulation

This paper investigates the possibility of robotically performing in situ needle manipulations to correct the needle tip position in the setting of robot-assisted, MRI-guided spinal injections, where real time MRI images cannot be effectively used to guide the needle. Open-loop control of the needle tip is derived from finite element simulation, and the proposed method is tested with ex vivo animal muscle tissues and validated by cone beam computed tomography. Preliminary results have shown promise of performing needle tip correction in situ to improve needle insertion accuracy when real-time feedback is not readily available.

Flexible Needle Bending Model for Spinal Injection Procedures

An in situ needle manipulation technique used by physicians when performing spinal injections is modeled to study its effect on needle shape and needle tip position. A mechanics-based model is proposed and solved using finite element method. A test setup is presented to mimic the needle manipulation motion. Tissue phantoms made from plastisol as well as porcine skeletal muscle samples are used to evaluate the model accuracy against medical images. The effect of different compression models as well as model parameters on model accuracy is studied, and the effect of needle-tissue interaction on the needle remote center of motion is examined. With the correct combination of compression model and model parameters, the model simulation is able to predict needle tip position within submillimeter accuracy.

The use of electronic conductivity devices can effectively reduce radiation exposure in vertebral body tethering

INTRODUCTION

Vertebral body tethering (VBT) presents new challenges in respect to radiation exposure, as screws cannot be placed free-hand and the lateral positioning of the patients increases scattered radiation. To reduce radiation exposure, we introduced the use of electronic conductivity device (ECD). These are drilling probes send an audio signal when cortical bone is breached. Thus, anterior, bicortical screws can be placed without multiple fluoroscopic controls. ECD has been used for all VBT procedures at our institution starting April 2020. The aim of this study was to test the safety of ECD and its efficacy in radiation reduction in comparison with the current standard, the fluoroscopic guidance.

MATERIALS AND METHODS

All patients who underwent VBT between August 2019 and December 2020 were retrospectively reviewed and divided into two groups according to whether ECD had been used or not. The radiation exposure per procedure and per screw was compared among the two groups, overall and separately for thoracic, lumbar and bilateral procedures. The rate of misplaced screws was calculated.

RESULTS

Data from 62 patients and 825 screws were obtained (397 with ECD). No screw misplacement was observed. Radiation reduction with ECD reached up to 41%. A significant reduction was observed in the radiation per procedure in bilateral instrumentation (from 9.16 to 5.52 mGy*m²), and in the analysis per screw overall (from 9.16 to 5.52 mGy*m²) and for lumbar curves (from 0.54 to 0.32 mGy*m²).

CONCLUSION

ECD can safely and effectively reduce the radiation exposure for VBT procedures.

[Intraoperative imaging of children and adolescents, for selected fractures and in follow-up after conservative and operative treatment : Part 2 of the results of a nationwide online survey of the Pediatric Traumatology Section of the German Trauma Society]

The indication for radiographic examinations in pediatric and adolescent trauma patients should follow ALARA (as low as reasonably achievable). Because of the effect of radiation on the growing sensitive tissues of these young patients, a strict indication should always be given for radiation use and during controls after fracture repair.

METHODS

An online survey by the Pediatric Traumatology Section (SKT) of the German Trauma Society (DGU) from Nov. 15, 2019, to Feb. 29, 2020, targeting trauma, pediatric, and general surgeons and orthopedic surgeons.

RESULTS

Participants: 788. Intraoperative applications: Collimation 50% always, postprocessing for magnification 40%, pulsed x-ray 47%, and 89% no continuous fluoroscopy; 63% osteosynthesis never directly on image intensifier. Radiographic controls after implant removal never used by 24%. After operated supracondylar humerus fracture, controls are performed up to 6 times. After distal radius greenstick fracture, 40% refrain from further X-ray controls, after conservatively treated clavicular shaft fracture, 55% refrain from further controls, others X-ray several times. After nondisplaced conservatively treated tibial shaft fracture, 63% recommend radiographic control after 1 week in two planes, 24% after 2 weeks, 37% after 4 weeks, and 32% after 6 weeks.

DISCUSSION

The analysis shows that there is no uniform radiological management of children and adolescents with fractures among the respondents. For some indications for the use of radiography, the benefit does not seem evident. The ALARA principle does not seem to be consistently followed.

CONCLUSION

Comparing the documented results of the survey with the consensus results of the SKT, differences are apparent.

Determination of scattered radiation dose for radiological staff during portable chest examinations of COVID-19 patients

The COVID-19 pandemic has resulted in a large increase in the number of patients admitted to hospitals. Radiological technologists (RTs) are often required to perform portable chest X-ray radiography on these patients. Normally, when performing a portable X-ray, radiation protection equipment is critical as it reduces the scatter radiation dose to hospital workers. However, during the pandemic, the use of a lead shield caused a heavy weight burden on workers who were responsible for a large number of patients. This study aimed to investigate scatter radiation doses received at various distances, directions, and positions. Radiation measurements were performed using the PBU-60 whole body phantom to determine scatter radiation doses at 100-200 cm and eight different angles around the phantom. The tests were conducted with and without lead shielding. Additionally, the doses were compared using the paired t test (p < 0.005) to determine suitable positions for workers who did not wear lead protection that adhered to radiation safety requirements. Scatter radiation doses of all 40 tests showed a highest and lowest value of 1285.5 nGy at 100 cm in the anteroposterior (AP) semi upright position and 134.7 nGy at 200 cm in the prone position, respectively. Correlation analysis between the dosimeter measurement and calculated inverse square law showed good correlation, with an R² value of 0.99. Without lead shielding, RTs must stay at a distance greater than 200 cm from patients for both vertical and horizontal beams to minimize scatter exposure. This would allow for an alternative way of performing portable chest radiography for COVID-19 patients without requiring lead shielding.

Development and experimental verification of C-arm camera shooting locator

This study aimed to develop a self-made C-arm camera shooting locator and verify its accuracy and advantages. A total of 60 physicians and nurses from the Surgical System of Sanmen People's Hospital, Zhejiang Province, China, were randomly selected as filming operators. The C-arm machine with a self-made locator and a C-arm machine without a locator were used to measure the center of the circular plate. The iron nails were used to shoot. The distance between the iron nail and the center point of the circular display area on display was defined as the shooting deviation. When it was less than 3 cm, the shooting was stopped. The number of shots, total shooting time, and first-shot deviation in the C-arm camera shooting groups with and without the locator were statistically analyzed, and the advantages and disadvantages of the two were compared. The average number of shots, average total shooting time, and average first-shot deviation of the C-arm camera using the locator were significantly better than those in the group without the locator, and the differences were statistically significant. When the shooting distance (X) was equal to 30 cm and the shooting angle (Y) was equal to 0°, the average number of shots, average total shooting time, and average first-shot deviation were optimal. The C-arm camera shooting locator can improve the shooting accuracy of the C-arm camera and effectively reduce the number of shots and total shooting time. Hence, it can be applied in clinical and surgical practice.

Knowledge and practice of radiation protection in the operating theater among orthopedic surgeons

Purpose

Many orthopedic procedures, particularly minimally invasive surgeries that require fluoroscopic imaging, present a radiation exposure risk to the orthopedic surgeon. Surgeons may have a higher risk of developing cancer if they receive significant amounts of radiation. Using personal protective equipment (PPE) and appropriate imaging device positioning, plays an important role in reducing the surgeon's radiation exposure. However, there is a lack of knowledge about the surgeon's radiation safety awareness and practices. Therefore, the aim of this study is to investigate the practices and radiation protection knowledge of orthopedic surgeons in the operating theater.

Approach

A nationwide survey was conducted from October 2021 to January 2022 to evaluate the radiation protection practices and awareness of orthopedic surgeons in Jordan. Normalized practice and knowledge scores were evaluated through the survey and compared between different groups. Descriptive statistics were used to present the surgeon's practices and radiation protection knowledge. Student's t -test was used to compare the outcomes between surgeons that received radiation protection training and surgeons who did not. Using ANOVA analysis, we compared the score outcomes for all the other variables.

Results

The surgeons that received radiation protection training had significantly higher practice score 39.6% compared with 31% for the group that did not have training ( p = 0.01 ). No statistically significant difference in the knowledge scores was found between the two groups. Although 91% of the surgeons reported using some kind of PPE, only 5.5% used a dosimeter badge during surgeries.

Conclusion

There is an obvious deficit in radiation safety training of orthopedic surgeons.

Novel MIS 3D NAV Single Step Pedicle Screw System (SSPSS): Workflow, Accuracy and Initial Clinical Experience

STUDY DESIGN

Prospective case series.

OBJECTIVE

SSPSS (single step pedicle screw system) was developed for minimally invasive spine surgery. We performed this study to report on safety, workflow, and our initial clinical experience with this novel technique.

METHODS

The prospective study was conducted on patients who underwent pedicle screw fixation between October 2017 and April 2018 using a novel single step 3D navigated pedicle screw system for MIS. Outcome measurements were obtained from intraoperative computerized tomography. The images were evaluated to determine pedicle wall penetration. We used a grading system to assess the severity of the pedicle wall penetration. Breaches were classified as grade 1 (<2 mm), grade 2 (2-4 mm), or grade 3 (<4 mm),¹ and as cranial, caudal, medial, and lateral.

RESULTS

Our study includes 135 screws in 24 patients. SSPSS eliminated K-wires and multiple steps traditionally necessary for MIS pedicle screw insertion. The median time per screw was 2.45 minutes. 3 screws were corrected intraoperatively. Pedicle wall penetration occurred in 14 screws (10%). Grade 1 breaches occurred in 4 screws (3%) and grade 2 breaches occurred in 10 screws (7%). Lateral breaches were observed more often than medial breaches. The accuracy rate in our study was 90% (Grade 0 breach). No revision surgeries were needed and no complications occurred.

CONCLUSIONS

Our study suggests that SSPSS could be a safe, accurate, and efficient tool. Our accuracy rate is comparable to that found in the literature.

RAY-POS: a LIDAR-based assistance system for intraoperative repositioning of mobile C-arms without external aids

PURPOSE

In current clinical practice, intraoperative repositioning of mobile C-arms is challenging due to a lack of visual cues and efficient guiding tools. This can be detrimental to the surgical workflow and lead to additional radiation burdens for both patient and personnel. To overcome this problem, we present our novel approach Lidar-based X-ray Positioning for Mobile C-arms (RAY-POS) for assisting circulating nurses during intraoperative C-arm repositioning without requiring external aids.

METHODS

RAY-POS consists of a localization module and a graphical user interface for guiding the user back to a previously recorded C-Arm position. We conducted a systematic comparison of simultaneous localization and mapping (SLAM) algorithms using different attachment positions of light detection and ranging (LIDAR) sensors to benchmark localization performance within the operating room (OR). For two promising combinations, we conducted further end-to-end repositioning tests within a realistic OR setup.

RESULTS

SLAM algorithm gmapping with a LIDAR sensor mounted 40 cm above the C-arm's horizontal unit performed best regarding localization accuracy and long-term stability. The distribution of the repositioning error yielded an effective standard deviation of 7.61 mm.

CONCLUSION

We conclude that a proof-of-concept for LIDAR-based C-arm repositioning without external aids has been achieved. In future work, we mainly aim at extending the capabilities of our system and evaluating the usability together with clinicians.

Technical Tips for Percutaneous Transforaminal Endoscopic Discectomy: A Three-step Maneuver for Puncture and Early Clinical Experience

OBJECTIVE

To investigate the feasibility and efficacy of percutaneous transforaminal endoscopic discectomy (PTED) with three-step maneuver for puncture (TSMP) for lumbar herniated disc (LDH).

METHODS

We performed a retrospective review of 30 patients who underwent PTED using TSMP for LDH and met inclusion criteria from January 2018 to September 2018. The primary outcome, leg or back pain, was assessed using Visual Analogue Scale (VAS). Patient surgical satisfaction was measured at 12 months post surgery using a five-point Likert scale. Potential prognostic factors measured were demographic characteristics, duration of symptom (DOS), and involved levels. Statistical analysis was performed using Fisher exact test and t-test. TSMP is a three-step maneuver that builds on the concept of needle puncture site and trajectory determination based on the principles of Kambin's triangle. First, accurate direction of the puncture is confirmed by inserting the needle horizontally. Then by gradually raising the needle tail in the manner described, the superior articular facet and the intervertebral foramen are sequentially located. Finally, the needle tip slides into the intervertebral foramen to reach the target superior articular facet.

RESULTS

Preoperative mean VAS was 7.6 ± 1.19, which decreased to 1.4 ± 0.97 at 12 months following treatment (P < 0.0001). Rates of surgical satisfaction per Likert scale were as follows: very satisfied and satisfied in 26 patients (86.7%). Three recurrent disc herniations of adjacent segmental levels were observed in the L5-S1 group at eight and 12 months after surgery. VAS scores at 12 months varied significantly between L4-L5 level surgery and L5-S1 level surgery groups (P < 0.01).

CONCLUSION

TSMP is a reliable technique for puncture into the intervertebral foramen.

Smart Technology and Orthopaedic Surgery: Current Concepts Regarding the Impact of Smartphones and Wearable Technology on Our Patients and Practice

PURPOSE OF REVIEW

While limited to case reports or small case series, emerging evidence advocates the inclusion of smartphone-interfacing mobile platforms and wearable technologies, consisting of internet-powered mobile and wearable devices that interface with smartphones, in the orthopaedic surgery practice. The purpose of this review is to investigate the relevance and impact of this technology in orthopaedic surgery.

RECENT FINDINGS

Smartphone-interfacing mobile platforms and wearable technologies are capable of improving the patients' quality of life as well as the extent of their therapeutic engagement, while promoting the orthopaedic surgeons' abilities and level of care. Offered advantages include improvements in diagnosis and examination, preoperative templating and planning, and intraoperative assistance, as well as postoperative monitoring and rehabilitation. Supplemental surgical exposure, through haptic feedback and realism of audio and video, may add another perspective to these innovations by simulating the operative environment and potentially adding a virtual tactile feature to the operator's visual experience. Although encouraging in the field of orthopaedic surgery, surgeons should be cautious when using smartphone-interfacing mobile platforms and wearable technologies, given the lack of a current academic governing board certification and clinical practice validation processes.

Augmented Reality (AR) in Orthopedics: Current Applications and Future Directions

PURPOSE OF REVIEW

Imaging technologies (X-ray, CT, MRI, and ultrasound) have revolutionized orthopedic surgery, allowing for the more efficient diagnosis, monitoring, and treatment of musculoskeletal aliments. The current review investigates recent literature surrounding the impact of augmented reality (AR) imaging technologies on orthopedic surgery. In particular, it investigates the impact that AR technologies may have on provider cognitive burden, operative times, occupational radiation exposure, and surgical precision and outcomes.

RECENT FINDINGS

Many AR technologies have been shown to lower provider cognitive burden and reduce operative time and radiation exposure while improving surgical precision in pre-clinical cadaveric and sawbones models. So far, only a few platforms focusing on pedicle screw placement have been approved by the FDA. These technologies have been implemented clinically with mixed results when compared to traditional free-hand approaches. It remains to be seen if current AR technologies can deliver upon their multitude of promises, and the ability to do so seems contingent upon continued technological progress. Additionally, the impact of these platforms will likely be highly conditional on clinical indication and provider type. It remains unclear if AR will be broadly accepted and utilized or if it will be reserved for niche indications where it adds significant value. One thing is clear, orthopedics' high utilization of pre- and intra-operative imaging, combined with the relative ease of tracking rigid structures like bone as compared to soft tissues, has made it the clear beachhead market for AR technologies in medicine.

Minimising radiation exposure to the surgeon in minimally invasive spine surgeries: A systematic review of 15 studies

BACKGROUND

Intraoperative imaging in minimally invasive spinal surgeries is associated with significant radiation exposure to surgeons, which overtime can lead to serious health hazards including malignancy. In this study, the authors conducted a systematic review to evaluate the efficacy of navigation assisted fluoroscopy methods on radiation exposure to the surgeon in minimally invasive spine surgeries, percutaneous endoscopic lumbar discectomy/percutaneous endoscopic transforaminal discectomy versus minimally invasive spine transforaminal lumbar interbody fusion (PELD/PETD versus MIS-TLIF).

METHODS

A systematic literature search was conducted using PUBMED/MEDLINE on 20th July, 2020. Inclusion criteria were applied according to study design, surgical technique, spinal region, and language. Data extracted included lumbar segment, average operation time (min), fluoroscopic time (s), and radiation dose (μSV), efficacy of modified navigation versus conventional techniques; on reducing operation, fluoroscopy times and effective radiation dose.

RESULTS

Fifteen studies (ten prospectives, and five retrospectives) were included for quantitative analysis. PELD recorded a shorter operation time (by 126.3min, p<0.001) and fluoroscopic time (by 22.9s, p=0.3) than MIS-TLIF. The highest radiation dose/case (μSV) for both techniques were recorded at the surgeon's: finger, chest, neck and eye. The effective dose for MIS-TLIF was 30μSV higher than PELD. Modified navigation techniques recorded a shorter operation time (by 15.9min, p=0.3); fluoroscopy time (by 289.8s, p=0.3); effective radiation dose (by 169.5μSV, p=0.3) than conventional fluoroscopy methods.

DISCUSSION

This systematic literature review showed that although navigation assisted fluoroscopy techniques are superior to conventional methods in minimising radiation exposure, lack of statistical significance warrants future randomised controlled trials, to solidify their efficacy in reducing radiation related hazards.

ESTIMATED EXPOSURE OF SPINE SURGEONS TO RADIATION

ABSTRACT Objective To estimate the amount of radiation received and accumulated in the bodies of two surgeons, one being the responsible surgeon and the other the assistant, performing spine surgery procedures over a period of 25 years. Methods Seventy-two spinal surgeries were performed during a seven-month period and the radiation loads were measured in both surgeons. The measurement of radiation was captured in fluoroscopy in anteroposterior and lateral incidences. The surgeon and the assistant used two dosimeters, one in the cervical region protecting the thyroid and the other on the lead apron in the genital region. The radioactive loads were measured in millisieverts and the accumulated charges were recorded monthly in both regions of the body in the two surgeons for seven months and the means for the work periods (1, 5, 10, 15, 20 and 25 years) were estimated. Results It was observed that in the surgeon the average accumulated radiation loads were 131.9% and 176.92% higher than those of the assistant in the cervical and genital regions, respectively. Conclusion While the use of X-rays is indispensable in routine orthopedic surgery, we have to consider the development of techniques of protection, rigor and discipline in the use of safety materials for surgeons. Preventive exposure reduction measures such as using thyroid protection equipment and turning the head away from the patient during fluoroscopy, among others, should be mandatory to promote less radiation exposure. Level of evidence II; Comparative prospective study.

What we know about intra-operative radiation exposure and hazards to operating theatre staff: A systematic review

BACKGROUND

The widespread adoption of minimally invasive surgery and increased use of intra-operative fluoroscopy places surgeons and trainees at risk of cumulative occupational radiation exposure. Unfortunately, there is limited published data specific to surgeons on the potential health implications. This study aims to review current literature regarding the hazards of cumulative radiation exposure among operating theatre staff.

METHODS

A systematic review was conducted of four databases for studies reporting on cumulative intra-operative radiation exposure for operating theatre staff and the hazards associated with prolonged and frequent use. References from relevant studies were screened for additional texts. English language studies, controlled trials and cross-sectional studies were included. Abstracts and full-text studies were assessed for relevance and eligibility independently by two authors using Covidence.

RESULTS

Six studies were included, with cancer being the most commonly reported long-term health hazard possibly associated with cumulative radiation exposure. A 1.85 fold greater prevalence of all cancers and 2.9 fold greater prevalence of breast cancer was reported amongst female orthopaedic surgeons compared to a sex- and age-adjusted population, but the results were not replicated amongst other surgical specialties. Multiple limitations of quantifying health risks of intra-operative radiation exposure were identified, including identifying a dose-effect relationship and confounders such as nulliparity and maternal age.

CONCLUSION

This article highlights the lack of robust evidence regarding the potential hazards of cumulative occupational intra-operative radiation exposure. This study demonstrates the importance of developing standardised national radiation safety protocols for surgical colleges and subspecialties to minimise risks to operating theatre staff.

Reduction of Radiation Exposure by Modifying Imaging Manner and Fluoroscopic Settings during Percutaneous Pedicle Screw Insertion

OBJECTIVE

Percutaneous pedicle screw (PPS) fixation is a needle based procedure that requires fluoroscopic image guidance. Consequently, radiation exposure is inevitable for patients, surgeons, and operation room staff. We hypothesize that reducing the production of radiation emission will result in reduced radiation exposure for everyone in the operation room. Research was performed to evaluate reduction of radiation exposure by modifying imaging manner and mode of radiation source.

METHODS

A total of 170 patients (680 screws) who underwent fusion surgery with PPS fixation from September 2019 to March 2020 were analyzed in this study. Personal dosimeters (Polimaster Ltd.) were worn at the collar outside a lead apron to measure radiation exposure. Patients were assigned to four groups based on imaging manner of fluoroscopy and radiation modification (pulse mode with reduced dose) : continuous use without radiation modification (group 1, n=34), intermittent use without radiation modification (group 2, n=54), continuous use with radiation modification (group 3, n=26), and intermittent use with radiation modification (group 4, n=56). Post hoc Tukey Honest significant difference test was used for individual comparisons of radiation exposure/screw and fluoroscopic time/screw.

RESULTS

The average radiation exposure/screw was 71.45±45.75 μSv/screw for group 1, 18.77±11.51 μSv/screw for group 2, 19.58±7.00 μSv/screw for group 3, and 4.26±2.89 μSv/screw for group 4. By changing imaging manner from continuous multiple shot to intermittent single shot, 73.7% radiation reduction was achieved in the no radiation modification groups (groups 1, 2), and 78.2% radiation reduction was achieved in the radiation modification groups (groups 3, 4). Radiation source modification from continuous mode with standard dose to pulse mode with reduced dose resulted in 72.6% radiation reduction in continuous imaging groups (groups 1, 3) and 77.3% radiation reduction in intermittent imaging groups (groups 2, 4). The average radiation exposure/screw was reduced 94.1% by changing imaging manner and modifying radiation source from continuous imaging with standard fluoroscopy setting (group 1) to intermittent imaging with modified fluoroscopy setting (group 4). A total of 680 screws were reviewed postoperatively, and 99.3% (675) were evaluated as pedicle breach grade 0 (<2 mm).

CONCLUSION

The average radiation exposure/screw for a spinal surgeon can be reduced 94.1% by changing imaging manner and modifying radiation source from real-time imaging with standard dose to intermittent imaging with modified dose. These modifications can be instantly applied to any procedure using fluoroscopic guidance and may reduce the overall radiation exposure of spine surgeons.

Does Surgical Experience Decrease Radiation Exposure in the Operating Room?

BACKGROUND

Intraoperative fluoroscopy facilitates minimally invasive surgery, and although it is irreplaceable in terms of intraoperative guidance, it results in substantial radiation exposure to the patient and surgical team. Although the risk of radiation exposure because of equipment factors has been described, there is little known about the impact of surgeon experience on radiation exposure. The aim of this study was to determine whether there is a relationship between years of surgical experience and total dose of radiation used for an archetypal pediatric orthopaedic surgical procedure that requires intraoperative fluoroscopy.

METHODS

This was a retrospective cohort study of children undergoing closed reduction and percutaneous pinning for supracondylar humerus fractures at a level I pediatric trauma center. Information pertaining to radiation dosage was gathered including fluoroscopic time, total images acquired, magnification use, and dose area product (DAP). Regression analysis was used to evaluate the effect of surgeon experience on the outcome variables.

RESULTS

A total of 759 pediatric patients treated by 17 attending surgeons were included. The median surgeon experience was 8.94 years (interquartile range, 5.9 to 19.8). Increased number of pins was associated with increased DAP (P<0.001) and lower years of experience (P=0.025). There was significantly higher fluoroscopy time in seconds (56.9 vs. 42.1 s, P=0.001), DAP (179.9 vs. 110.3 mGy-cm2, P=0.001), use of magnification (39.5 vs. 31.9 s, P=0.043), and total number of images obtained (74.5 vs. 57.6, P=0.008) in attending surgeons with <1 year of experience compared with those with greater experience. An operator extremity was visible in at least 1 saved image in 263 of 759 (35%) cases.

CONCLUSION

Increased surgical experience was significantly associated with decreased fluoroscopy usage, including time, number of images, and dose. Surgeon inexperience increases radiation exposure for patients and staff by over 60% when treating supracondylar humerus fractures. This study clearly identifies methods to reduce radiation exposure, including use of pulsed fluoroscopy instead of continuous fluoroscopy, decreasing use of magnification, removing the operator's extremity from the field, and judicious use and placement of each additional pin.

LEVEL OF EVIDENCE

Level III.

Intraoperative risks of radiation exposure for the surgeon and patient

Intraoperative radiological imaging serves an essential role in many spine surgery procedures. It is critical that patients, staff and physicians have an adequate understanding of the risks and benefits associated with radiation exposure for all involved. In this review, we briefly introduce the current trends associated with intraoperative radiological imaging. With the increased utilization of minimally invasive spine surgery (MIS) techniques, the benefits of intraoperative imaging have become even more important. Less surgical exposure, however, often equates to an increased requirement for intraoperative imaging. Understanding the conventions for radiation measurement, radiological fundamental concepts, along with deterministic or stochastic effects gives a framework for conceptualizing how radiation exposure relates to the risk of various sequela. Additionally, we describe the various options surgeons have for intraoperative imaging modalities including those based on conventional fluoroscopy, computer tomography, and magnetic resonance imaging. We also describe different ways to prevent unnecessary radiation exposure including dose reduction, better education, and use of personal protective equipment (PPE). Finally, we conclude with a reflection on the progress that has been made to limit intraoperative radiation exposure and the promise of future technology and policy.

Shielding effect of radiation dose reduction fiber during the use of C-arm fluoroscopy: a phantom study

This study evaluated the shielding effect of a newly developed dose-reduction fiber (DRF) made from barium sulfate, in terms of radiation doses delivered to patients' radiosensitive organs and operator during C-arm fluoroscopy and its impact on the quality of images. A C-arm fluoroscopy unit was placed beside a whole-body phantom. Radiophotoluminescent glass dosimeters were attached to the back and front of the whole-body phantom at 20 cm intervals. Radiation doses were measured without DRF and with it applied to the back (position 1), front (position 2) or both sides (position 3) of the phantom. To investigate the impact of DRF on the quality of fluoroscopic images, step-wedge and modulation transfer function phantoms were used. The absorbed radiation doses to the back of the phantom significantly decreased by 25.3-88.8% after applying DRF to positions 1 and 3. The absorbed radiation doses to the front of the phantom significantly decreased by 55.3-93.6% after applying DRF to positions 2 and 3. The contrast resolution values for each adjacent step area fell in the range 0.0119-0.0209, 0.0128-0.0271, 0.0135-0.0339 and 0.0152-0.0339 without and with DRF applied to positions 1, 2 and 3, respectively. The investigated DRF effectively reduces absorbed radiation doses to patients and operators without decreasing the quality of C-arm fluoroscopic images. Therefore, routine clinical use of the DRF is recommended during the use of C-arm fluoroscopy.

Patient exposure and diagnostic reference levels in operating rooms: a multi-centric retrospective study in over 150 private and public French clinics

To investigate patient exposure in operating rooms and establish Diagnostic Reference Levels (DRLs), fifteen different procedures and nearly 4500 surgeries performed between January 2017 and December 2019 at over 150 different private (79% of data) and public (21% of data) French clinics were recorded. Collected information include the used C-arm equipment, exposure parameters (kVp, mAs, Fluoroscopy Time - FT and Air Kerma-Area Product - PKA) and patient Body Mass Index (BMI) whenever available. Multi-centric DRLs were derived as the 75th percentile of the median exposure data collected in more than 10 different hospitals. For the less frequent procedures, DRLs were determined as the 75th percentile of pooled exposure data with a minimum of 4 centres and 100 patients. Patient exposure proved to be significantly different among the centres. Highest DRLs were found for Abdominal Aortic Aneurysm Endoprosthesis (18 min, 81 Gy cm2), Iliac Angioplasty (6 min, 24 Gy cm2) and Flutter Ablation surgeries (17 min, 14 Gy cm2). In opposition, lowest DRLs were obtained for Hallux Valgus (0.4 min, 0.04 Gy cm2), Hand/Wrist Fracture (0.6 min, 0.16 Gy cm2), and Venous Access Device Implantation surgeries (0.3 min, 0.36 Gy cm2). Similar exposure levels are registered in private clinics and public hospitals. Multi-centric DRLs for fifteen surgical procedures including six new reference values were established to help optimise patients' radiation protection.

C-Arm-Free Circumferential Minimally Invasive Surgery for Adult Spinal Deformity: Technical Note

BACKGROUND

Circumferential minimally invasive surgery (cMIS), as a technique for reducing the complications of adult spinal deformity surgery, is receiving considerable attention. Conventional cMIS is performed using intraoperative fluoroscopy. In this work, we describe a new cMIS technique without using C-arm fluoroscopy for correcting adult spinal deformities.

CASE DESCRIPTION

A 70-year-old woman with symptomatic adult spinal deformity was referred to our hospital. The patient's daily life has been affected by severe low back pain for more than 4 years. The surgery was performed without C-arm fluoroscopy. The percutaneous pedicle screws and intervertebral cages were inserted only under navigation guidance. The patient was successfully treated with surgery, and her low back pain was well controlled. Her clinical outcomes were as follows: Oswestry Disability Index improved from 64% to 14% and the low back pain visual analog scale score improved from 75 mm to 24 mm at 1 year of final follow-up.

CONCLUSIONS

C-arm-free cMIS for adult spinal deformity is a useful technique that reduces percutaneous screw and cage misplacement. With this new technique, the surgeons and the operation room staff can avoid the risk of an adverse event of intraoperative radiation.

Evolution of imaging in surgical fracture management

Intraoperative imaging has been advanced substantially over the last decades. It supports localization of the region of interest, verification of the preoperatively classified fracture pattern, identification of correct insertion point of the implant, placement of instruments and fixation material, and verification of correct fracture reduction and implant positioning. While conventional fluoroscopic 2D imaging remains the gold standard in intraoperative imaging, critical anatomical regions are predestined for intraoperative 3D imaging. Additional options such as perioperative virtual planning, simulation, and surgical training, 3D printing techniques and 3D augmented reality visualization may potentially open new windows to improve surgical results in fracture care. This manuscript presents an update on current and upcoming imaging techniques in orthopaedic and trauma surgery focusing on technical advances for decreasing malreduction, malalignment, and malposition, as well as tips and tricks for daily surgical practice in order to improve clinical outcomes and patients' and surgeons' safety.

Radiation exposure in the treatment of pediatric supracondylar humerus fractures

PURPOSE

To determine the factors that influence radiation exposure during repair of supracondylar humerus fractures.

METHODS

Medical records of almost 200 children with supracondylar fractures were retrospectively analyzed for variables correlated with fluoroscopy time and radiation dose as measures of radiation exposure.

RESULTS

There was no statistically significant difference in fluoroscopy time (27 vs. 22 s p = 0.345) or direct radiation dose (0.394 vs. 0.318 mSv p = 0.290) between uniplanar and biplanar C-arm use. No statistically significant differences in fluoroscopy time or radiation dose were found for surgical technique, comorbid ipsilateral fractures, preoperative neurovascular compromise, or resident participation. There was a significant 8.3 s increase in fluoroscopy time (p = 0.022) and 0.249 mSv increase in radiation dose (p = 0.020) as the fracture type increased from II to III. An increase in one pin during CRPP resulted in a statistically significant 10.4 s increase in fluoroscopy time and a 0.205 mSv increase in radiation dose. There were significant differences between the physician with the lowest fluoroscopy time and radiation dose compared with the physicians with the two highest values for both fluoroscopy time and radiation dose (p < 0.01).

CONCLUSIONS

We found no significant difference in direct radiation exposure or fluoroscopy time when comparing biplanar to uniplanar C-arm use, resident participation, preoperative neurovascular compromise, or for comorbid ipsilateral fractures. Both outcomes increased significantly as fracture type increased from II to III and as the number of pins used during CRPP increased. Both outcomes were significantly different between the surgeons performing CRPP.

Treatment of Cervical Spine Fractures and Subluxations without the Use of Intraoperative Fluoroscopy in Resource-Limited Settings

Background  Surgical management of subaxial cervical spine injuries remains challenging. Although intraoperative fluoroscopy is usually used for intraoperative spinal level localization (SLL), it is unavailable in most developing countries. The surgeon therefore has to rely on anatomic landmarks. In our setting, in the absence of intraoperative fluoroscopy, we used the carotid tubercle for SLL. Herein we evaluate the accuracy and reliability of the carotid tubercle as a landmark during surgery for traumatic cervical spine injury.

Methods  This was a retrospective cohort study on 34 patients undergoing anterior cervical surgery for subaxial cervical spine fractures and/or subluxation between January 2005 and February 2011. From their medical records, the patients’ sociodemographic, clinical, radiological, and operative data were retrieved and analyzed.

Results  Thirty-four patients were included in the study. The mean age was 36.2 years. Thirty patients were males. The mean duration between the trauma and surgical intervention was 9.6 days. Six patients were completely tetraplegic. Fourteen patients had fractures and 20 patients had subluxation. The carotid tubercle was palpable in all the 34 cases. Twenty-two (68.8%) patients had partial or complete neurologic recovery. Complete anatomic reduction was achieved in 30 cases. One case of slight malalignment of the plate was observed. No case of significant deviation nor penetration of the screw into the vertebral canal was found. One patient died.

Conclusions  Carotid tubercle, a palpable intrinsic marker, is an attractive anatomic landmark for SLL during surgeries for traumatic spine injuries in resource-limited settings.

Immersive Radiation Experience for Interventional Radiology with Virtual Reality Radiation Dose Visualization Using Fast Monte Carlo Dose Estimation

For interventional radiology (IR), understanding the precise dose distribution is crucial to reduce the risks of radiation dermatitis to patients and staff. Visualization of dose distribution is expected to support radiation safety efforts immensely. This report presents techniques for perceiving the dose distribution using virtual reality (VR) technology and for estimating the air dose distribution accurately using Monte Carlo simulation for VR dose visualization. We adopted an earlier reported Monte-Carlo-based estimation system for IR and simulated the dose in a geometrical area resembling an IR room with fluoroscopic conditions. Users of our VR system experienced a simulated air dose distribution in the IR room while the irradiation angle, irradiation timing, and lead shielding were controlled. The estimated air dose was evaluated through comparison with measurements taken using a radiophotoluminescence glass dosimeter. Our dose estimation results were consistent with dosimeter readings, showing a 13.5% average mutual difference. The estimated air dose was visualized in VR: users could view a virtual IR room and walk around in it. Using our VR system, users experienced dose distribution changes dynamically with C-arm rotation. Qualitative tests were conducted to evaluate the workload and usability of our VR system. The perceived overall workload score (18.00) was lower than the scores reported in the literature for medical tasks (50.60) and computer activities (54.00). This VR visualization is expected to open new horizons for understanding dose distributions intuitively, thereby aiding the avoidance of radiation injury.

Measuring the performance of patient-specific solutions for minimally invasive transforaminal lumbar interbody fusion surgery

Pre-surgical planning using 3D-printed BioModels enables the preparation of a "patient-specific" kit to assist instrumented spinal fusion surgery. This approach has the potential to decrease operating time while also offering logistical benefits and cost savings for healthcare. We report our experience with this method in 129 consecutive patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) over 27 months at a single centre and performed by a single surgeon. Patient imaging and surgical planning software were used to manufacture a 3D-printed patient-specific MIS TLIF kit for each patient consisting of a 1:1 scale spine BioModel, stereotactic K-wire guide, osteotomy guide, and retractors. Pre-selected pedicle screws, rods, and cages were sourced and supplied with the patient-specific kit. Additional implants were available on-shelf to address a size discrepancy between the kit implant and intraoperative measurements. Each BioModel was used pre-operatively for surgical planning, patient consent and education. The BioModel was sterilised for intraoperative reference and navigation purposes. Efficiency measures included operating time (153 ± 44 min), sterile tray usage (14 ± 3), fluoroscopy screening time (57.2 ± 23.7 s), operative waste (19 ± 8 L contaminated, 116 ± 30 L uncontaminated), and median hospital stay (4 days). The pre-selected kit implants exactly matched intraoperative measurements for 597/639 pedicle screws, 249/258 rods, and 46/148 cages. Pedicle screw placement accuracy was 97.8% (625/639) on postoperative CT. Complications included one intraoperative dural tear, no blood products administered, and six reoperations. Our experience demonstrates a viable application of patient-specific 3D-printed solutions and provides a benchmark for studies of efficiency in spinal fusion surgery.

Does nonexistent of your hands on the screen guarantee no radiation exposure to your body? - Study on exposure of the practitioner's hands to radiation during C-arm fluoroscopy-guided injections and effectiveness of a new shielding device

Observational phantom study.This study aimed to evaluate the radiation exposure dose of practitioner's hands when performing C-arm guided procedures and to determine the usefulness of our newly designed radiation shielding device.C-arm guided procedures including lumbar transforaminal epidural steroid injections (TFESIs) are commonly used for pain control induced by lumbar radiculopathy. The practitioner's hands are vulnerable to radiation exposure because of the long exposure time and short distance from the radiation resource. No studies to date have reported the cumulative exposure of the physician's hands according to location and exposure time.Using a chest phantom irradiated with X-rays under lumbar TFESI conditions, cumulative scatter radiation dose was measured at 36 points using a dosimeter. The measurements were checked at 1, 3, 5, 10 minutes of radiation exposure. The experiment was repeated using our newly designed shielding device.Significant radiation accumulation was observed in the field where the practitioner's hands might be placed during C-arm guided procedures. The further the distance from the radiation resource and the shorter the exposure time, the smaller was the cumulative radiation expose dose. The new shielding device showed an excellent shielding rate (66.0%-99.9%) when the dosimeter was within the shielding range. However, at some points, increased accumulated radiation exposure dose was observed, although the dosimeter was within the range of the shielding device.To reduce radiation exposure of the practitioner's hands when performing C-arm-guided procedures, the radiation exposure time should be decreased and a greater distance from the radiation resource should be maintained. When using our shielding device, placing the hand close to the device surface and minimizing the time using fluoroscopy minimized the radiation exposure of the hand.

A new method for reducing operation time and radiation exposure in the placement of Jamshidi needles: Technical note

Percutaneous pedicle screws have been used in the treatment of thoracolumbar fractures for decades, and conventional fluoroscopy is commonly used to confirm the positions of the Jamshidi needles during the procedure. In this article, a modified method is reported for the placement of Jamshidi needles. The attending surgeons did not receive any radiation during the procedure and the fluoroscopy time for the patients was little. In our method, all six Jamshidi needles were placed on the pedicles and hammered 2 mm into each entry site. When the verification images were acquired, the medical personnel went behind a lead-lined wall. The positions of the needles were first reviewed and adjusted as needed based on the anterior-posterior (AP) image. Then, the C-arm was rotated and lateral images were obtained to further verify the needle placement. The rest of the screw placement procedure remained the same. The proposed technique was applied in 45 patients with thoracolumbar fractures. It took an average (range) of 5 (4-7) single-shot images to ensure all the needles were positioned at the ideal entry site and 12 (10-17) minutes to complete this step. No neurological symptoms were reported by the patients. Using the proposed technique, the radiation exposure for the surgeons is zero, and the patients are well-protected from excessive radiation exposure. This modified method of embedding all the Jamshidi needles at the entry sites before fluoroscopy is an improved technique compared with the conventional method.

Is actual surgical experience reflected in virtual reality simulation surgery for a femoral neck fracture?

INTRODUCTION

A virtual reality simulator developed for orthopaedic and trauma surgical training has been introduced. However, it is unclear whether the experiences of actual surgery are reflected in virtual reality simulation surgery (VRSS) using a simulator. The aim of this study is to investigate whether the results in VRSS differ between a trauma expert and a trauma novice.

METHODS

In Group A (expert), there are ten orthopaedic trauma surgeons and in Group B (novice) ten residents within 2 years after medical school graduation. VRSS for a femoral neck fracture using Hansson hook-pins (Test 1) and Hansson twin hook plate (Test 2) was performed. The parameters evaluated were total procedure time (s), fluoroscopy time (s), number of times X-ray was used (defined by the number of times the foot pedal was used), number of retries in guide placement, and final implant position.

RESULTS

In Test 1, the averages of four parameters (distance to posterior cortex (p = 0.009), distal pin distance above lesser trochanter (p = 0.015), distal pin hook angular error (p = 0.004), and distal pin tip distance to centre (lateral) (p = 0.015)) were significantly different between Groups A and B. In Test 2, no parameters in a mean were significantly different between groups, but seven parameters in a variance (guide wire distance to joint surface (p = 0.0191), twin hook length outside barrel (p = 0.011), twin hook tip distance to centre (lateral) (p = 0.042), twin hook distance to centre of lateral cortex (lateral) (p = 0.016), plate end alignment error (lateral) (p = 0.027), guide wire angle with lateral cortex (front) (p = 0.024), and 3.2-mm drill outside cortex (p = 0.000)) were significantly different between groups. In Test 1, Group B showed significantly longer fluoroscopy time than Group A (p = 0.044). In Test 2, Group B showed significantly fewer instances of X-ray use than Group A (p = 0.046).

CONCLUSIONS

Our study showed that the experiences of actual surgery are reflected in the result of VRSS using the simulator.

Radiation Safety Perceptions and Practices Among Pediatric Anesthesiologists: A Survey of the Physician Membership of the Society for Pediatric Anesthesia

BACKGROUND

Pediatric anesthesiologists are exposed to ionizing radiation from x-rays on an almost daily basis. Our goal was to determine the culture of safety in which they work and how they adhere to preventative strategies that minimize exposure risk in their daily practice.

METHODS

After Institutional Review Board waiver and approval of the Society for Pediatric Anesthesia's research and quality and safety committees, an electronic e-mail questionnaire was sent to the Society's physician, nontrainee members and consisted of questions specific to provider use of protective lead shielding, the routine use of dosimeters, and demographic information. Univariate analyses were performed using the Wilcoxon rank sum test for ordinal variables, the Fisher exact test for categorical variables, and the Spearman test to analyze correlation between 2 ordinal variables, while a proportional odds logistic regression was used for a multivariable ordinal outcome analysis. P values of <.05 were considered statistically significant.

RESULTS

Twenty-one percent (674/3151) of the surveyed anesthesiologists completed the online questionnaire. Radiation exposure is ubiquitous (98.7%), and regardless of sex, most respondents were either concerned or very concerned about radiation exposure (76.8%); however, women were significantly more concerned than men (proportional odds ratio, 1.66 [95% confidence interval, 1.20-2.31]; P = .002). Despite this and independent of sex, level of concern was not associated with use of a radiation dosimeter (P = .85), lead glasses (odds ratio, 1.07 [95% confidence interval, 0.52-2.39]; P = 1.0), or a thyroid shield (P = .12). Dosimeters were rarely (13%) or never used (52%) and were mandated in only 28.5% of institutions. Virtually none of the respondents had ever taken a radiation safety course, received a personal radiation dose report, notification of their radiation exposure, or knew how many millirem/y was considered safe. Half of the respondents were female, and while pregnant, 73% (151/206) tried to avoid radiation exposure by requesting not to be assigned to cases requiring x-rays. These requests were honored 78% (160/206) of the time.

DISCUSSION

Despite universal exposure to ionizing radiation from x-rays, pediatric anesthesiologists do not routinely adhere to strategies designed to limit the intensity of this exposure and rarely work in institutions in which a culture of radiation safety exists. Our study highlights the need to improve radiation safety education, the need to change the safety culture within the operating rooms and imaging suites, and the need to more fully investigate the utility of dosimeters, lead shielding, and eye safety measures in pediatric anesthesia practice.

Effect of metallic tools on scattered radiation dose during the use of C-arm fluoroscopy in orthopaedic surgery

This study investigated the effect of metallic tools on the scattered radiation dose delivered to surgeons' radiosensitive organs while simulating hip surgery using C-arm fluoroscopy. Two phantoms, a pelvis and a Rando phantom, were used to simulate a patient and a surgeon in this study. Photoluminescence dosimeters were inserted into the Rando phantom in the positions of the eye, thyroid and gonad. A drill was positioned above the hip of the pelvis phantom or beside the pelvis phantom of the same height. For each drill location, the scattered radiation dose was measured when the angle to the operator phantom was 45°; this was repeated when the angle was 90°. The scattered radiation doses to the eye, thyroid and gonad when the drill was placed beside the pelvis phantom with 90° angulation to the operator phantom were significantly lower than the reference values and those when the drill was placed beside the pelvis phantom at a 45° angulation to the operator phantom. The scattered radiation doses to the eye and thyroid when the drill was placed above the hip were significantly lower than the references values. Of the four different scenarios, the scattered radiation doses to the eye, thyroid and gonad were lowest when the drill was placed beside the pelvis phantom with 90° angulation. This study showed that the scattered radiation doses to radiosensitive organs were affected by the location and angle of the metallic tools in relation to the operator. Therefore, orthopedic surgeons should consider the effect of metallic tools on the scattered radiation dose during intraoperative use of C-arm fluoroscopy.

RADIATION EXPOSURE DURING SPINE SURGERY USING C-ARM FLUOROSCOPY

OBJECTIVE

To evaluate the radiation dose received by staff in spine surgeries, including those who are not considered occupationally exposed workers.

METHODS

All spinal surgeries performed in the same department during a period of 12 months were evaluated with regard to the exposure of surgeons, scrub nurses, and auxiliary personnel working in the operating room to radiation from C-arm fluoroscopy. Radiation was measured by 15 film badge dosimeters placed on the professionals' lapels, gloves, and room standardized sites. The films were analyzed in the dosimetry laboratory by collections per period.

RESULTS

During the 12 months, 81 spinal surgeries were performed by the same team, with surgical times ranging from 1 to 6 hours. The total radiation dose ranged from 0.16 mSv to 2.29 mSv depending on the dosimetry site. The most exposed site was the wrist of the main surgeon.

CONCLUSION

The results showed that in the spinal surgeries in our setting, the radiation doses are low and within legal limits. Nevertheless, constant training of professionals is essential for radiation protection of medical staff and patients. Level of evidence I/b, exploratory cohort study.

Mini C-Arm Fluoroscopy: Does Its Configuration Matter for Radiation Exposure to the Surgeon?

BACKGROUND

The risk of occupational radiation exposure to the surgeon associated with the use of a mini C-arm has yet to reach a wide consensus. Using a distal radius fracture surgery model, we tested the hypothesis that radiation exposure to the surgeon's critical body parts is independent of mini C-arm configuration.

METHODS

An anthropomorphic mannequin (representing the upper body of a 60" male surgeon) was seated at a hand table as if operating on a volar-plated wrist Sawbone model. Thermoluminescent dosimeters measured radiation exposure to the surgeon's eyes, thyroid, chest, hand, and groin from a mini C-arm fluoroscopy unit in 3 commonly used configurations: vertical (source above table), inverted (source below table), and horizontal (with beam parallel to table surface). The fluoroscope scanned the wrist model for 15 continuous minutes in triplicate for each orientation.

RESULTS

Radiation to the hand was significantly greatest in all mini C-arm positions compared with all other anatomic sites irrespective of C-arm position. Hand radiation exposure was greatest in the horizontal position (2887.09 mrem), versus the vertical and inverted positions (59.79 mrem, 31.10 mrem, P < .001). Eye radiation exposure was significantly greater in the inverted position (2.33 mrem) compared with the vertical (0.67 mrem, P = .024), and horizontal positions (0.33 mrem, P = .012). No significant difference in radiation exposure was found at the thyroid, chest, and groin sites, at each of the 3 C-arm configurations.

CONCLUSIONS

The model's hand received almost 1000 times more radiation exposure than all other anatomic sites with statistically greatest radiation exposure sustained in the horizontal position. Eye radiation exposure with the C-arm in the inverted position (below the table) was also significantly greater.

Radiation exposure to the surgeon during minimally invasive spine procedures is directly estimated by patient dose

PURPOSE

Radiation exposure is a necessary component of minimally invasive spine procedures to augment limited visualization of anatomy. The surgeon's exposure to ionizing radiation is not easily recognizable without a digital dosimeter-something few surgeons have access to. The aim of this study was to identify an easy alternative method that uses the available radiation dose data from the C-arm to accurately predict physician exposure.

METHODS

The senior surgeon wore a digital dosimeter during all minimally invasive spine fusion procedures performed over a 12-month period. Patient demographics, procedure information, and radiation exposure throughout the procedure were recorded.

RESULTS

Fifty-five minimally invasive spine fusions utilizing 330 percutaneous screws were included. Average radiation dose was 0.46 Rad/screw to the patient. Average radiation exposure to the surgeon was 1.06 ± 0.71 μSv/screw, with a strong positive correlation (r = 0.77) to patient dose. The coefficient of determination (r²) was 0.5928, meaning almost two-thirds of the variability in radiation exposure to the surgeon is explained by radiation exposure to the patient.

CONCLUSIONS

Intra-operative radiation exposure to the patient, which is easily identifiable as a continuously updated fluoroscopic monitor, is a reliable predictor of radiation exposure to the surgeon during percutaneous screw placement in minimally invasive spinal fusion surgery and therefore can provide an estimate of exposure without the use of a dosimeter. With this, a surgeon can better understand the magnitude of their exposure on a case-by-case basis rather than on a quarterly basis, or more likely, not at all. These slides can be retrieved under Electronic Supplementary Material.

C-arm fluoroscopy in orthopaedic surgical practice

The use of C-arm fluoroscopy in intraoperative orthopaedic procedures has become an important tool in modern orthopaedic surgical practice. It enhances the technical proficiency of the surgeon in addition to reducing the morbidity and length of hospital stay of the patient. Despite the documented benefits of this device, there has been a growing concern about the increased radiation exposure to the surgical team. We therefore present the review of the literature on the usefulness of C-arm fluoroscopy, pitfalls in application of the machine as well as the harmful radiation effects and precautionary measures that need to be observed when using the C-arm fluoroscopy in orthopaedic surgical procedures.