Radiation exposure to the surgeon during fluoroscopically assisted percutaneous vertebroplasty: a prospective study

Robot-assisted percutaneous vertebroplasty for osteoporotic vertebral compression fracture treatment and risk factor screening for postoperative refracture

Osteoporotic vertebral compression fracture (OVCF) is a serious complication of osteoporosis, and percutaneous vertebroplasty (PVP) is a major therapeutic method for OVCF. This study aimed to evaluate the clinical efficacy and postoperative complications of robot-assisted targeted PVP for the treatment of OVCF. The data from 202 OVCF patients were analyzed in this study, including 72 cases received traditional PVP (PVP group), 68 cases received robot-assisted PVP (R-PVP group), and 62 cases underwent robot-assisted PVP combined with targeted plugging (R-PVP + TP group). The fluoroscopic exposure conditions, operative duration, lengths of stay, postoperative bone cement leakage, refracture, Visual Analog Scale (VAS) score, and Oswestry Disability Index (ODI) score were obtained and compared between the three groups. The Kaplan-Meier method and logistic regression model were adopted to screen the risk factors related with postoperative refracture. R-PVP and R-PVP + TP group had significantly reduced fluoroscopic frequency and radiation dose, and reduced cement leakage compared with PVP group. R-PVP + TP not only showed more obvious advantages in these aspects, but also had a lower probability of postoperative refracture. In addition, BMD, fracture vertebral distribution, cement leakage, and surgery methods were independent related with refracture. All the results demonstrated robot assistance could improve the application of PVP in the treatment of OVCF, and robot-assisted PVP combined with targeted plugging showed significantly reduced fluoroscopic exposure, bone cement leakage, and rate of postoperative refracture. BMD, fracture vertebral distribution, cement leakage, and operation methods were identified as four risk factors for the onset of refracture after PVP.

The Impact of Implementing a Radiation-Sparing Protocol for Percutaneous Kyphoplasty-A Prospective Dosemetric Study

STUDY DESIGN

Prospective cohort study.

OBJECTIVES

The purpose of this prospective study was to evaluate a protocol for radiation-sparing kyphoplasty by assessing dosemetrically recorded radiation exposures to both patient and surgeon.

METHODS

This prospective clinical study examines the radiation exposure to patient and surgeon during single-level kyphoplasty in 32 thoracolumbar osteoporotic vertebral body fractures (12 OF 2, 9 OF 3, 11 OF 4 types) using a radiation aware surgical protocol between May 2017 and November 2019. The radiation exposure was measured at different locations using film, eye lens and ring dosemeters. Dose values are reported under consideration of lower detection limits of each dosemeter type.

RESULTS

A high proportion of dosemeter readings was below the lower detection limits, especially for the surgeon (>90%). Radiation exposure to the surgeon was highest at the unprotected thyroid gland (0.053 ± 0.047 mSv), however only slightly above the lower detection limit of dosemeters (0.044 mSv). Radiation exposure to the patient was highest at the chest (0.349 ± 0.414 mSv) and the gonad (0.186 ± 0.262 mSv). Fluoroscopy time, dose area product and number of fluoroscopic images were 46.0 ± 17.9 sec, 124 ± 109 cGy×cm2, and 35 ± 13 per kyphoplasty, respectively. Back pain significantly improved from 6.8 ± 1.6 to 2.5 ± 1.7 on the numeric rating scale on the first postoperative day (P < 0.0001).

CONCLUSIONS

The implementation of a strict intraoperative radiation protection protocol allows for safely performed kyphoplasty with ultra-low radiation exposure for the patient and surgeon without exceeding the annual occupational dose limits.

TRIAL REGISTRATION

The study was registered in the German Clinical Trials Register (DRKS00011908, registration date 16/05/2017).

Robot-assisted percutaneous vertebroplasty for osteoporotic vertebral compression fractures: a retrospective matched-cohort study

PURPOSE

This study aims to introduce the principle, clinical efficacy, and learning curve of robot-assisted percutaneous vertebroplasty (PVP).

METHODS

Forty-two patients who underwent robot-assisted single-level PVP were analyzed retrospectively and 42 age-matched patients using freehand technique were selected as the control group. The visual analog scale, operation time, radiation exposure, accuracy, and learning curve were analyzed.

RESULTS

The puncture time and total operation time were significantly shorter, and the puncture and total fluoroscopy number were fewer in the robot group. The deviation between pre-operative planned and actual puncture trajectory well met clinical requirement. The puncture time, total operation time, and puncture fluoroscopy number were significantly more in early cases than in later cases in the robot group.

CONCLUSION

The robot-assisted pedicle puncture technique shortens the operation time and reduces radiation exposure, and the accuracy meets the clinical requirement in PVP. The learning curve is short and not steep.

Prospective analysis of intraoperative radiation dose in foot and ankle surgery using mini-C-arm fluoroscopy. Continuous series of 1064 procedures

INTRODUCTION

Foot and ankle surgeons make daily use of mini-C-arm fluoroscopes. The present study aimed to quantify associated radiation doses.

HYPOTHESIS

X-ray exposure for foot and ankle surgeons using a mini-C-arm fluoroscope is below the nuclear safety authority authorized doses of 20 mSv/year for the whole body and crystalline lens, 150 mSv/year for the thyroid and 500 mSv/year for the skin and limbs.

MATERIAL AND METHODS

A single-center, single-surgeon prospective series was treated between February 2014 and December 2017. Doses emitted by the mini-C-arm (15cm field) were recorded during 1,064 operations. Doses received by the surgeon were recorded by 3 passive dosimeters (thorax, eyes and hands) and 1 active dosimeter. The significance threshold was set at p<0.05.

RESULTS

A total of 64.4% of procedures concerned the forefoot, 35.3% the hindfoot and ankle, and 0.3% were strictly percutaneous. Mean dose-area product (DAP) per procedure was 3.9 cGy/cm²±7: in forefoot surgery, 1.1 cGy/cm²±0.9, and in hindfoot and ankle surgery 8.7 cGy/cm²±9.7 (p<0.05), for mean irradiation times of 7.6s±5.3 and 36.7s±35.5 respectively and image numbers 4.1±2.7 and 18.7±20.5. Total ankle replacement was associated with the highest doses: 20.1 cGy/cm²±14.7. Mean daily active dosimetry was 2.2μSv±1.4. Mean annual dose to the hand, crystalline lens and deep (Hp(10)) and shallow (Hp(0.07)) whole body was respectively 1.28 mSv, 0.6 mSv, 0.31 mSv and 0.19 mSv. The highest annual exposure was recorded for the hands: 2.68 mSv in 2015. There was a significant linear relationship between daily active dosimetry and daily emission: daily active dosimetry=(DAP×0.11)+0.54, for a correlation coefficient of 0.77.

DISCUSSION/CONCLUSION

The exposure of foot and ankle surgeons using mini-C-arms was well below threshold, and also lower than in the literature.

LEVEL OF EVIDENCE

IV.

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.

A 5-YEAR RETROSPECTIVE ANALYSIS OF IONIZING RADIATION DOSE TO HYBRID OPERATING ROOM PERSONNEL IN SAUDI ARABIA

The annual average effective dose (ED) for operating room personnel (ORP) in Saudi Arabia was estimated from the period of 2015-2019 using thermoluminescent dosemeters. A retrospective analysis was conducted on annual EDs for 7530 ORP working across 52 hospitals. These workers were only exposed to radiation in the operating room. The annual average ED over the period of 5 years was found to be 0.59 mSv with no incidence of a dose above the annual dose limit of 20 mSv. The maximum annual ED reported was 15 mSv for an operating room worker in 2019. More than 88% of the workers received an annual ED of <1 mSv. The study concluded that the work environment in hybrid operating rooms across Saudi Arabia is safe. However, it is always recommended that workers take every protective measure when dealing with ionization radiation.

Comparison of operator and patient radiation exposure during fluoroscopy-guided vertebroplasty and kyphoplasty: a systematic review and meta-analysis

OBJECTIVE

Percutaneous vertebroplasty (PV) and balloon kyphoplasty (BK) are two minimally invasive techniques used to treat mechanical pain secondary to spinal compression fractures. A concern for both procedures is the radiation exposure incurred by both operators and patients. The authors conducted a systematic review of the available literature to examine differences in interventionalist radiation exposure between PV and BK and differences in patient radiation exposure between PV and BK.

METHODS

The authors conducted a search of the PubMed, Ovid Medline, Cochrane Reviews, Embase, and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Full-text articles in English describing one of the primary endpoints in ≥ 5 unique patients treated with PV or BK of the mobile spine were included. Estimates of mean operative time, radiation exposure, and fluoroscopy duration were reported as weighted averages. Additionally, annual occupational dose limits provided by the United States Nuclear Regulatory Commission (USNRC) were used to determine the number needed to harm (NNH).

RESULTS

The meta-analysis included 27 articles. For PV, the mean fluoroscopy times were 4.9 ± 3.3 minutes per level without protective measures and 5.2 ± 3.4 minutes with protective measures. The mean operator radiation exposures per level in mrem were 4.6 ± 5.4 at the eye, 7.8 ± 8.7 at the neck, 22.7 ± 62.4 at the torso, and 49.2 ± 62.2 at the hand without protective equipment and 0.3 ± 0.1 at the torso and 95.5 ± 162.5 at the hand with protection. The mean fluoroscopy times per level for BK were 6.1 ± 2.5 minutes without protective measures and 6.0 ± 3.2 minutes with such measures. The mean exposures were 31.3 ± 39.3, 19.7 ± 4.6, 31.8 ± 34.2, and 174.4 ± 117.3 mrem at the eye, neck, torso, and hand, respectively, without protection, and 1, 9.2 ± 26.2, and 187.7 ± 100.4 mrem at the neck, torso, and hand, respectively, with protective equipment. For protected procedures, radiation to the hand was the limiting factor and the NNH estimates were 524 ± 891 and 266 ± 142 for PV and BK, respectively. Patient exposure as measured by flank-mounted dosimeters, entrance skin dose, and dose area product demonstrated lower exposure with PV than BK (p < 0.01).

CONCLUSIONS

Operator radiation exposure is significantly decreased by the use of protective equipment. Radiation exposure to both the operator and patient is lower for PV than BK. NNH estimates suggest that radiation to the hand limits the number of procedures an operator can safely perform. In particular, radiation to the hand limits PV to 524 and BK to 266 procedures per year before surpassing the threshold set by the USNRC.

Collimation Reduces Radiation Exposure to the Surgeon in Endoscopic Spine Surgery: A Prospective Study

BACKGROUND AND STUDY AIMS

 There are no previous studies in the literature comparing the radiation dose to which surgeons are exposed while using a standard fluoroscopy versus collimation during transforaminal percutaneous endoscopic lumbar diskectomy (PELD). The aim of this study is to compare this and to evaluate the effectiveness of collimation in reducing radiation exposure.

METHODS

 In this study, the operating surgeon (single surgeon) placed a gamma radiation dosimeter on his chest outside of the lead apron during transforaminal PELD surgeries and measured the radiation exposure immediately after each surgery. As foraminoplasty using free-hand reamers is a longer procedure and requires more fluoroscopy shots, we divided the patients into two groups. The first group consisted of 24 patients (nonforaminoplasty group). The second group consisted of 13 patients (foraminoplasty group). We compared the radiation exposure to the operating surgeon using a standard fluoroscopy versus collimation for each group individually and overall. We randomized the patients within each group based on the order in which they had their respective procedures.

RESULTS

 We analyzed 39 patients who underwent transforaminal PELD between May and December 2019. In both groups, as well as overall, the recorded radiation exposure to the surgeon was significantly lower in surgeries in which collimation was used. In the first group, the radiation dose was 0.083 versus 0.039 mSv per surgery (p = 0.019), whereas in the second group, it was 0.153 versus 0.041 mSv per surgery (p = 0.001), and overall it was 0.108 versus 0.039 mSv per surgery (p < 0.001).

CONCLUSION

 The use of collimation during transforaminal PELD significantly reduces spine the surgeon's exposure to radiation. Therefore, spine surgeons should consider using collimation during transforaminal PELD.

A novel "three-dimensional-printed individual guide template-assisted percutaneous vertebroplasty" for osteoporotic vertebral compression fracture: a prospective, controlled study

BACKGROUND

Conventional percutaneous vertebroplasty (PVP) are mainly guided by C-arm fluoroscopy, and it usually leads to excessive X-ray radiation exposure to patients, surgeons, and anesthetists. Moreover, multi-time fluoroscope may prolong the operation time. 3D-printed template could help minimize fluoroscopy shot times and fluoroscopy dosage during operation, and shorten operation time. We perform this study to compare the efficacy and accuracy of PVP assisted by "three-dimensional printed individual guide template" versus conventional PVP.

METHOD

Patients who suffered acute painful single segment osteoporotic vertebral compression fracture(OVCF) needed operative treatment were randomly assigned into three-dimensional printing individual guide template-assisted percutaneous vertebroplasty group (group A) or conventional PVP guided by C-arm fluoroscopy group (group B) at a 1:1 ratio. Fluoroscopy times for puncture points (FTPP), total radiation dosages (TRD), total fluoroscopy time (TFT), and total operation time (TOT) were recorded as the main evaluation factors to evaluate the two operation procedures.

RESULTS

A total of 36 acute painful single segment OVCF patients were successfully operated on, and each group has 18 patients. None of the patients presented symptomatic complications. The surgical success rate in group A was 94.4%(17/18), one patient in the group A was failed and then operated by conventional procedure. FTPP (1.8 ± 0.8 in group A vs 5.2 ± 1.9 in group B, P < 0.05), TRD (4.9 ± 0.9 mGy vs 7.9 ± 1.6 mGy, P < 0.05), TFT (16.7 ± 2.9 vs 26.6 ± 5.3, P < 0.05), and total operation time (19.4 ± 2.4 min vs 27.8 ± 4.0 min, P < 0.05) were presented statistically difference in the two groups. The incidence of cement leakage occurred in group A (3/18, 16.7%) was less than that occurred in group B (7/18, 38.9%) (P > 0.05).

CONCLUSIONS

Compared with the conventional PVP, "three-dimensional-printed individual guide template-assisted PVP" could minimize fluoroscopy shot times during operation and fluoroscopy dosage, shorten operation time, and is a more precise and feasible operation method.

TRIAL REGISTRATION

The present study was registered with the Chinese Clinical Trial Registry (ChiCTR) ( http://www.chictr.org.cn ), and its registration no. is ChiCTR1900024283.

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.

Patients' and Physicians' Knowledge of Radiation Exposure Related to Spine Surgery

STUDY DESIGN

Cross-sectional survey.

OBJECTIVE

Examine patients' and physicians' estimates of radiation exposure related to spine surgery.

SUMMARY OF BACKGROUND DATA

Patients are commonly exposed to radiation when undergoing spine surgery. Previous studies suggest that patients and physicians have limited knowledge about radiation exposure in the outpatient setting. This has not been assessed for intraoperative imaging.

METHODS

A questionnaire was developed to assess awareness/knowledge of radiation exposure in outpatient and intraoperative spine care settings. Patients and surgeons estimated chest radiograph (CXR) equivalent radiation from: cervical and lumbar radiographs (anterior-posterior [AP] and lateral), computed tomography (CT), magnetic resonance imaging (MRI), intraoperative fluoroscopy, and intraoperative CT (O-arm). Results were compared to literature-reported radiation doses.

RESULTS

Overall, 100 patients and 26 providers completed the survey. Only 31% of patients were informed about outpatient radiation exposure, and only 23% of those who had undergone spine surgery had been informed about intraoperative radiation exposure. For lumbar radiographs, patients and surgeons underestimated CXR-equivalent radiation exposures: AP by five-fold (P < 0.0001) and seven-fold (P < 0.0001), respectively, and lateral by three-fold (P < 0.0001) and four-fold (P = 0.0002), respectively. For cervical CT imaging, patients and surgeons underestimated radiation exposure by 18-fold (P < 0.0001) and two-fold (P = 0.0339), respectively. For lumbar CT imaging, patients and surgeons underestimated radiation exposure by 31-fold (P < 0.0001) and three-fold (P = 0.0001), respectively. For intraoperative specific cervical and lumbar imaging, patients underestimated radiation exposure for O-arm by 11-fold (P < 0.0001) and 22-fold (P = 0.0002), respectively. Surgeons underestimated radiation exposure of lumbar O-arm by three-fold (P = 0.0227).

CONCLUSION

This study evaluated patient and physician knowledge of radiation exposure related to spine procedures. Underestimation of radiation exposure in the outpatient setting was consistent with prior study findings. The significant underestimation of intraoperative cross-sectional imaging (O-arm) is notable and needs attention in the era of increased use of such technology for imaging, navigation, and robotic spine surgery.

LEVEL OF EVIDENCE

4.

The safety and accuracy of robot-assisted pedicle screw internal fixation for spine disease: a meta-analysis

Aims

The aim of this study was to systematically compare the safety and accuracy of robot-assisted (RA) technique with conventional freehand with/without fluoroscopy-assisted (CT) pedicle screw insertion for spine disease.

Methods

A systematic search was performed on PubMed, EMBASE, the Cochrane Library, MEDLINE, China National Knowledge Infrastructure (CNKI), and WANFANG for randomized controlled trials (RCTs) that investigated the safety and accuracy of RA compared with conventional freehand with/without fluoroscopy-assisted pedicle screw insertion for spine disease from 2012 to 2019. This meta-analysis used Mantel-Haenszel or inverse variance method with mixed-effects model for heterogeneity, calculating the odds ratio (OR), mean difference (MD), standardized mean difference (SMD), and 95% confidence intervals (CIs). The results of heterogeneity, subgroup analysis, and risk of bias were analyzed.

Results

Ten RCTs with 713 patients and 3,331 pedicle screws were included. Compared with CT, the accuracy rate of RA was superior in Grade A with statistical significance and Grade A + B without statistical significance. Compared with CT, the operating time of RA was longer. The difference between RA and CT was statistically significant in radiation dose. Proximal facet joint violation occurred less in RA than in CT. The postoperative Oswestry Disability Index (ODI) of RA was smaller than that of CT, and there were some interesting outcomes in our subgroup analysis.

Conclusion

RA technique could be viewed as an accurate and safe pedicle screw implantation method compared to CT. A robotic system equipped with optical intraoperative navigation is superior to CT in accuracy. RA pedicle screw insertion can improve accuracy and maintain stability for some challenging areas.Cite this article: Bone Joint Res 2020;9(10):653-666.

Comparison of the Accuracy of C1 Pedicle Screw Fixation Using Fluoroscopy and Free-Hand Techniques in Patients With Posterior Arch Thickness of Less Than 4 mm

BACKGROUND

C1 pedicle screw insertion is not easy, and more fluoroscopy can be required for safe insertion. Fluoroscopy is time consuming and increases patient radiation exposure. There have been no studies comparing the accuracy of C1 pedicle screw insertion using the fluoroscopy and free-hand techniques.

OBJECTIVE

To describe a free-hand C1 pedicle screw insertion method in patients with the posterior arch thickness of less than 4 mm in the thinnest part of the groove, and to compare the clinical and radiological outcomes of C1 pedicle screw insertion using fluoroscopy vs using the free-hand technique.

METHODS

A total of 25 patients who had atlantoaxial instability with a C1 posterior arch &lt;4 mm and were treated with C1 pedicle screw insertion were included. In 10 patients, fluoroscopy was used for C1 pedicle screw insertion, and 15 patients underwent the free-hand technique. We compared the radiologic and clinical outcomes between the 2 groups.

RESULTS

In patients who underwent the free-hand technique, 96.5% of screws were rated as safe (grade A or B), and 80.0% of screws in the fluoroscopy group were rated as safe. Postoperative occipital neuralgia occurred in one patient in the fluoroscopy group and did not occur in the free-hand technique group. There was no significant difference in the improvement of Nurick grade between the 2 groups.

CONCLUSION

C1 pedicle screw insertion using the free-hand technique is feasible and safe in patients with a C1 posterior arch &lt;4 mm.

Radiation Dose to the Eye Lens Through Radiological Imaging Procedures at the Surgical Workplace During Trauma Surgery

Background: Due to the drastic reduction of the eye lens dose limit from 150 mSv per year to 20 mSv per year since 2018, the prospective investigation of the estimated dose of the eye lens by radiological imaging procedures at the surgical site during trauma surgery in the daily work process was carried out. This was also necessary because, as experience shows, with changes in surgical techniques, there are also changes in the use of radiological procedures, and thus an up-to-date inventory can provide valuable information for the assessment of occupationally induced radiation exposure of surgical personnel under the current conditions. Methods: The eye lens radiation exposure was measured over three months for five trauma surgeons, four hand surgeons and four surgical assistants with personalized LPS-TLD-TD 07 partial body dosimeters Hp (0.07). A reference dosimeter was deposited at the surgery changing room. The dosimeters were sent to the LPS (Landesanstalt für Personendosimetrie und Strahlenschutzausbildung) measuring institute (National Institute for Personal Dosimetry and Radiation Protection Training, Berlin) for evaluation after 3 months. The duration of the operation, occupation (assistant, surgeon, etc.), type of surgery (procedure, diagnosis), designation of the X-ray unit, total duration of radiation exposure per operation and dose area product per operation were recorded. Results: Both the evaluation of the dosimeters by the trauma surgeons and the evaluation of the dosimeters by the hand surgeons and the surgical assistants revealed no significant radiation exposure of the eye lens in comparison to the respective measured reference dosimeters. Conclusions: Despite the drastic reduction of the eye lens dose limit from 150 mSv per year to 20 mSv per year, the limit for orthopedic, trauma and hand surgery operations is well below the limit in this setting.

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.

"Targeted Percutaneous Vertebroplasty" Versus Traditional Percutaneous Vertebroplasty for Osteoporotic Vertebral Compression Fracture

Objective. In this randomized, nonblinded, controlled study, the feasibility and precision of "targeted percutaneous vertebroplasty" ("targeted PVP") for osteoporotic vertebral compression fracture (OVCF) was evaluated. Methods. A total of 42 patients, aged 50 to 87 years, with OVCF were randomly divided into 2 groups: A and B. Group A underwent "targeted PVP," and group B underwent traditional PVP with the guidance of C-arm fluoroscopy. Fluoroscopy times for skin puncture points (FTSPP), total radiation doses (TRD), total fluoroscopy times (TFT), and operation time were set as the main evaluation indicators. Results. FTSPP (1.52 ± 0.51 in group A vs 6.62 ± 2.58 in group B, U < .001), TRD (6.26 ± 1.51 in group A vs 11.32 ± 4.21 in group B, P < .001), TFT (16.57 ± 2.79 in group A vs 26.05 ± 6.18 in group B, P < .001), and operation time (20.05 ± 3.38 in group A vs 25.43 ±5.11 in group B, U < .001) were statistically different in the 2 groups. The incidence of cement leakage that occurred in group A (1/21, 4.76%) was significantly less than that in group B (9/21, 42.9%, P < 0.05). Conclusions. "Targeted PVP" may achieve (1) less skin positioning fluoroscopy times, less total fluoroscopy times and dose, shorter operation time, which is more precise than traditional PVP; (2) less incidence of cement leakage; and (3) visualization of the fractured vertebra, which is probably more valuable for the treatment of complicated OVCF patients.

Reduction of operator radiation exposure using a passive robotic device during fluoroscopy-guided arterial puncture: an experimental study in a swine model

Background

Vascular interventions imply radiation exposure to the operating physician (OP). To reduce radiation exposure, we propose a novel passive robotic device for fluoroscopy-guided arterial puncturing.

Methods

X-ray dose rates were measured for a total of 30 fluoroscopy-guided puncture femoral arteries in 15 pigs. Fifteen punctures were performed with the device while the other 15 were performed without the device by an interventional cardiologist with 10 years of experience. Parametric t test was used.

Results

The success rate with the device was 100%. Overall, the OP received more radiation (0.41 mSv/h) as compared to the assistant (0.06 mSv/h) (p <  0.001) and, amongst OP’s body parts, hands received more radiation than other body parts (p <  0.001). The radiation dose rate to the OP’s hands during arterial puncturing performed manually without the device was 0.95 ± 0.25 mSv/h whereas it was 0.14 ± 0.006 mSv/h using the device, resulting in an 85% reduction (p <  0.001). For the head, the dose was reduced from 0.16 mSv/h to 0.08 mSv/h (50% reduction, p <  0.001), and for the dominant arm, from 0.12 mSv/h to 0.07 mSv/h (42% reduction, p <  0.001). The fluoroscopy time was reduced from 4.5 ± 0.15 min to 4.3 ± 0.11 min device (p = 0.002).

Conclusions

In a swine model, fluoroscopy time and radiation exposure for the OP puncturing femoral artery were significantly reduced by using the passive robotic device.

Surgeon's and patient's radiation exposure during percutaneous thoraco-lumbar pedicle screw fixation: A prospective multicenter study of 100 cases

HYPOTHESIS

Percutaneous pedicle screw fixations (PPSF) are increasingly used in spine surgery, minimizing morbidity through less muscle breakdown but at the cost of intraoperative fluoroscopic guidance that generates high radiation exposure. Few studies have been conducted to measure them accurately.

MATERIAL AND METHODS

The objective of our study is to quantify, during a PPSF carried out in different experimented centers respecting current radiation protection recommendations, this irradiation at the level of the surgeon and the patient. We have prospectively included 100 FPVP procedures for which we have collected radiation doses from the main operator. For each procedure, the doses of whole-body radiation, lens and extremities were measured.

RESULTS

Our results show a mean whole body, extremity and lens exposure dose per procedure reaching 1.7±2.8μSv, 204.7±260.9μSv and 30.5±25.9μSv, respectively. According to these values, the exposure of the surgeon's extremities and lens will exceed the annual limit allowed by the International Commission on Radiological Protection (ICRP) after 2440 and 4840 procedures respectively.

CONCLUSION

Recent European guidelines will reduce the maximum annual exposure dose from 150 to 20mSv. The number of surgical procedures to not reach the eye threshold, according to our results, should not exceed 645 procedures per year. Pending the democratization of neuronavigation systems, the use of conventional fluoroscopy exposes the eyes in the first place. Therefore they must be protected by leaded glasses.

LEVEL OF PROOF

IV, case series.

Reduced Radiation Exposure and Puncture Time of Percutaneous Transpedicular Puncture with Real-Time Ultrasound Volume Navigation

OBJECTIVES

The present study introduced ultrasound volume navigation (UVN) to reduce the radiation exposure and puncture time of percutaneous transpedicular puncture in percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP).

METHODS

We retrospectively reviewed the medical records of patients with osteoporotic vertebral compression fracture who had undergone PVP or PKP guided by UVN or fluoroscopy from September 2017 to December 2017.

RESULTS

We enrolled 10 patients (6 women, 4 men) with 24 pedicles involved in the present study. Significant reductions in fluoroscopy frequency (2.58 vs. 17.42; P < 0.01), exposure time (2.36 vs. 15.69 seconds; P < 0.01), and puncture time (4.13 vs. 19.21 minutes; P < 0.01) for each pedicle were observed in the UVN group compared with the fluoroscopy group. Obvious correlations among fluoroscopy frequency, exposure time, and puncture time for each pedicle were observed (P < 0.01). The visual analog scale scores and Oswestry Disability Index were both significantly improved after the procedures. All patients achieved excellent or good clinical outcomes. No complications were observed in any patient.

CONCLUSIONS

UVN could obviously reduce the radiation exposure and puncture time of percutaneous transpedicular puncture in PVP and PKP.

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.

Intraoperative Computed Tomography Navigational Assistance for Transforaminal Endoscopic Decompression of Heterotopic Foraminal Bone Formation After Oblique Lumbar Interbody Fusion

Transforaminal endoscopic spine surgery is an emerging technique in spine surgery, but it offers 2 distinct challenges to spine surgeons looking to adopt it: 1) targeting spine pathology and 2) understanding the endoscopic anatomy visualized through the endoscope. Intraoperative computed tomography (CT)-guided navigation is also an emerging technique in spine surgery that is becoming widely adopted for its benefits in assisting surgeons in localizing pathology and guided spine instrumentation placement. In this technical note, we describe a technique that uses intraoperative CT-guided navigation concomitantly with a transforaminal endoscopic approach to decompress a L4-L5 foraminal heterotopic bone formation after an oblique lumbar interbody fusion. The addition of intraoperative CT-guided navigation proved beneficial in targeting the pathology during the procedure and ensuring that the pathology was resolved by offering postoperative CT visualization of the decompressed neural foramen.

MEASUREMENT OF RADIATION DOSES TO THE EYE LENS DURING ORTHOPEDIC SURGERY USING AN C-ARM X-RAY SYSTEM

The present study aimed to determine doses delivered to the eye lenses of surgeons while using the inverted-C-arm technique and the protective effect of leaded spectacles during orthopedic surgery. The kerma in air was measured at five positions on leaded glasses positioned near the eye lens and on the neck using small optically stimulated luminescence (OSL) dosemeters. The lens equivalent dose was also measured at the neck using an OSL dosemeter. The maximum equivalent dose to the eye lens and the maximum kerma were 0.8 mSv/month and 0.66 mGy/month, respectively. The leaded glasses reduced the exposure by ~60%. Even if the surgeons are exposed to the maximum dose of X-ray radiation for 5 years, the equivalent doses to the eye lens will not exceed the present limit recommended by the ICRP.

Is lead shielding of patients necessary during fluoroscopic procedures? A study based on kyphoplasty

OBJECTIVE

To determine the benefits, risks, and limitations associated with wrapping a patient with lead shielding during fluoroscopy-guided kyphoplasty procedures as a way to reduce operator radiation exposure.

MATERIALS AND METHODS

An anthropomorphic phantom was used to mimic a patient undergoing a kyphoplasty procedure under fluoroscopic guidance. Radiation measurements of the air kerma rate (AKR) were made at several locations and under various experimental conditions. First, AKR was measured at various angles along the horizontal plane of the phantom and at varying distances from the phantom, both with and without a lead apron wrapped around the lower portion of the phantom (referred to here as phantom shielding). Second, the effect of an operator's apron was simulated by suspending a lead apron between the phantom and the measurement device. AKR was measured for the four shielding conditions-phantom shielding only, operator apron only, both phantom shielding and operator apron, and no shielding. Third, AKR measurements were made at various heights and with varying C-arm angle.

RESULTS

At all locations, the phantom shielding provided no substantial protection beyond that provided by an operator's own lead apron. Phantom shielding did not reduce AKR at a height comparable to that of an operator's head.

CONCLUSIONS

Previous reports of using patient shielding to reduce operator exposure fail to consider the role of an operator's own lead apron in radiation protection. For an operator wearing appropriate personal lead apparel, patient shielding provides no substantial reduction in operator dose.

Cervical spine disease in surgeons performing arthroscopy or laparoscopy

Minimal research exists regarding cervical spine disorders in surgeons who perform endoscopy. A confidential on-line survey regarding neck pain (NP), spine disease (SD), and radiculopathy/myelopathy (R/M) was sent to 722 surgeons from a managed, group-based health care system. 415 responded. 361 had endoscopy experience, of whom 24.4% had NP, 20.8% SD, and 3.9% R/M. Most respondents were less than 50 years of age (62.3%), and male (65.7%). Significant risk factors for NP included older age and female, whereas OB/Gyn specialty, increased age and job stress were for SD. After adjusting for age and gender, significant risk factors for NP and SD included greater surgeon experience. After also adjusting for job stress, significant risk factors for SD included increased surgeon experience and higher frequency of endoscopies. No association was found between use of digital OR. Endoscopy appears to place surgeons at higher risk of cervical disease. Level of Evidence: Level 3.

The Great Unknown-A systematic literature review about risk associated with intraoperative imaging during orthopaedic surgeries

INTRODUCTION

Modern techniques in orthopaedic surgery using minimally invasive procedures, and increased use of fluoroscopic imaging present a potential increased risk to surgeons due to ionizing radiation exposure. This article is a systematic review of recent literature on radiation exposure of orthopaedic surgeons.

MATERIALS AND METHODS

Pubmed and Cochrane searches were performed on intraoperative radiation exposure covering English and German articles published between 1.1.2000 and 11.8.2014. Inclusion criteria were clinical studies and systematic literature reviews focusing on radiation exposure of orthopaedic surgeons during surgical procedures of the musculoskeletal system reporting either effective dose (whole body) or equivalent dose at the organ level. All included articles were reviewed with focus on the surgical specialty, the procedure type, the imaging system used, the radiation measurement method, the fluoroscopy time, the radiation exposure, the use of radiation protection, and any references to specific safety guidelines.

RESULTS

Thirty-four eligible publications were identified. However, the lack of well-designed studies focusing on radiation exposure of surgeons prevents pooling of data. Highest exposure and subsequent equivalent doses were reported from spinal surgery (up to 4.8mSv of equivalent dose to the hand) and intramedullary nailing (up to 0.142mSV of equivalent dose to the thyroid). Radiation exposure was reduced by 96.9% and 94.2% when wearing a thyroid collar and a lead apron.

CONCLUSIONS

With the increasing use of intraoperative imaging, there is a growing need for radiation awareness by the operating surgeon. Strict adherence to radiation protection should be enforced to protect in-training surgeons. Strategies to reduce exposure include C-arm position, distance, protective wear, and new imaging technologies. Radiation exposure is harmful and action should be taken to minimize exposure.

Accuracy of a new intraoperative cone beam CT imaging technique (Artis zeego II) compared to postoperative CT scan for assessment of pedicle screws placement and breaches detection

PURPOSE

The goal of this study was to compare the accuracy of a novel intraoperative cone beam computed tomography (CBCT) imaging technique with that of conventional computed tomography (CT) scans for assessment of pedicle screw placement and breach detection.

METHODS

Three hundred and forty-eight pedicle screws were inserted in 58 patients between October 2013 and March 2016. All patients had an intraoperative CBCT scan and a conventional CT scan to verify the placement of the screws. The CBCT and CT images were reviewed by two surgeons to assess the accuracy of screw placement and detect pedicle breaches using two established classification systems. Agreement on screw placement between intraoperative CBCT and postoperative CT was assessed using Kappa and Gwet's coefficients. Using CT scanning as the gold standard, the sensitivity, specificity, positive predictive value, and negative predictive value were calculated to determine the ability of CBCT imaging to accurately evaluate screw placement.

RESULTS

The Kappa coefficient was 0.78 using the Gertzbein classification and 0.80 using the Heary classification, indicating a substantial agreement between the intraoperative CBCT and postoperative CT images. Gwet's coefficient was 0.94 for both classifications, indicating almost perfect agreement. The sensitivity, specificity, positive predictive value and negative predictive value of the CBCT images were 77, 98, 86, and 96%, respectively, for the Gertzbein classification and 79, 98, 88, and 96%, respectively, for the Heary classification.

CONCLUSIONS

Intraoperative CBCT provides accurate assessment of pedicle screw placement and enables intraoperative repositioning of misplaced screws. This technique may make postoperative CT imaging unnecessary.

Significant reduction of fluoroscopy repetition with lumbar localization system in minimally invasive spine surgery: A prospective study

The conventional location methods for minimally invasive spinal surgery (MISS) were mainly based on repeated fluoroscopy in a trial-and-error manner preoperatively and intraoperatively. Localization system mainly consisted of preoperative applied radiopaque frame and intraoperative guiding device, which has the potential to minimize fluoroscopy repetition in MISS. The study aimed to evaluate the efficacy of a novel lumbar localization system in reducing radiation exposure to patients.Included patients underwent minimally invasive transforaminal lumbar interbody fusion (MISTLIF) or percutaneous transforaminal endoscopic discectomy (PTED). Patients treated with novel localization system were regarded as Group A, and patients treated without novel localization system were regarded as Group B.For PTED, The estimated effective dose was 0.41 ± 0.13 mSv in Group A and 0.57 ± 0.14 mSv in Group B (P < .001); the fluoroscopy exposure time of PTED was 22.18 ± 7.30 seconds in Group A and 30.53 ± 7.56 seconds in Group B (P < .001); The estimated cancer risk of radiation exposure was 22.68 ± 7.38 (10) in Group A and 31.20 ± 7.96 (10) in Group B (P < .001). For MISTLIF, the estimated effective dose was 0.45 ± 0.09 mSv in Group A and 0.58 ± 0.09 mSv in Group B (P < .001); The fluoroscopy exposure time was 25.41 ± 5.52 seconds in Group A and 32.82 ± 5.03 seconds in Group B (P < .001); The estimated cancer risk was 24.90 ± 5.15 (10) in Group A and 31.96 ± 5.04 (10) in Group B (P < .001). There were also significant differences in localization time and operation time between the 2 groups either for MISTLIF or PTED.The lumbar localization system could be a potential protection strategy for minimizing radiation hazards.

Patient radiation exposure during transforaminal lumbar endoscopic spine surgery: a prospective study

OBJECTIVE The aim of this study was to describe patient radiation exposure during single-level transforaminal endoscopic lumbar discectomy procedures at levels L2-5 and L5-S1. METHODS Radiation exposure was monitored in 151 consecutive patients undergoing single-level transforaminal endoscopic lumbar discectomy procedures. Two groups were studied: patients undergoing procedures at the L4-5 level or above and those undergoing an L5-S1 procedure. RESULTS For the discectomy procedures at L4-5 and above, the average duration of fluoroscopy was 38.4 seconds and the mean calculated patient radiation exposure dose was 1.5 mSv. For the L5-S1 procedures, average fluoroscopy time was 54.6 seconds and the mean calculated radiation exposure dose was 2.1 mSv. The average patient radiation exposure dose among these cases represents a 3.5-fold decrease compared with the senior surgeon's first 100 cases. CONCLUSIONS Transforaminal lumbar endoscopic discectomy can be used as a minimally invasive technique for the treatment of lumbar radiculopathy in the setting of a herniated lumbar disc without the significant concern of exposing the patient to harmful doses of radiation. One caveat is that both the surgeon and the patient are likely to be exposed to higher doses of radiation during a surgeon's early experience in minimally invasive endoscopic spine surgery.

Ionizing Radiation Doses Detected at the Eye Level of the Primary Surgeon During Orthopaedic Procedures

OBJECTIVES

To evaluate the ionizing radiation dose received by the eyes of orthopaedic surgeons during various orthopaedic procedures. Secondary objective was to compare the ionizing radiation dose received between differing experience level.

DESIGN

Prospective comparative study between January 2013 and May 2014.

SETTING

Westmead Hospital, a Level 1 Trauma Centre for Greater Western Sydney.

PARTICIPANTS

A total of 26 surgeons volunteered to participate within the study.

INTERVENTION

Experience level, procedure performed, fluoroscopy time, dose area product, total air kerma, and eye dose received was recorded. Participants were evaluated on procedure and experience level.

MAIN OUTCOME MEASUREMENTS

Radiation dose received at eye level by the primary surgeon during an orthopaedic procedure.

RESULTS

Data from a total of 131 cases was recorded and included for analysis. The mean radiation dose detected at the eye level of the primary surgeon was 0.02 mSv (SD = 0.05 mSv) per procedure. Radiation at eye level was only detected in 31 of the 131 cases. The highest registered dose for a single procedure was 0.31 mSv. Femoral nails and pelvic fixation procedures had a significantly higher mean dose received than other procedure groups (0.04 mSv (SD = 0.07 mSv) and 0.04 mSv (SD = 0.06 mSv), respectively). Comparing the eye doses received by orthopaedic consultants and trainees, there was no significant difference between the 2 groups.

CONCLUSIONS

The risk of harmful levels of radiation exposure at eye level to orthopaedic surgeons is low. This risk is greatest during insertion of femoral intramedullary nails and pelvic fixation, and it is recommended that in these situations, surgeons take all reasonable precautions to minimize radiation dose. The orthopaedic trainees in this study were not subjected to higher doses of radiation than their consultant trainers. On the basis of these results, most of the orthopaedic surgeons remain well below the yearly radiation dose of 20 mSv as recommended by the International Commission on Radiological Protection.

Efficiency of lead aprons in blocking radiation - how protective are they?

BACKGROUND

Despite the firmly established occupational risk of exposure to X-rays, they are used extensively in spine surgeries. Shielding by lead aprons is the most common protective practice. We quantified the level of their radiation blocking ability in a real-life setting.

METHODS

Single-center, prospective, randomized study of adult patients with degenerative lumbar disorders, scheduled to undergo posterior lumbar interbody fusion. Instrumentation was performed in either a robot-assisted, minimally invasive approach (RO) or a conventional, fluoroscopically-assisted, open approach (FA). Outcome measures included the quantitative measurement of the surgeon's actual exposure to radiation, as recorded by thermo-luminescent dosimeters (TLD) worn both above and under the 0.5 mm thyroid and trunk lead protectors.

FINDINGS

Sixty four patients were included in this study, 34 in the RO cohort and 30 in the FA cohort. The radiation blocked by the aprons, represented as the ratio of the under-apron to above-apron TLDs, averaged 37.1% (range 25.4-48.3%, 95% confidence interval between 30.6-43.6%). In the RO cohort, the average per-screw radiation dose and time were 51.9% and 73.7% lower, respectively, than the per screw exposure in the FA cohort.

INTERPRETATION

The 0.5 mm lead aprons blocked just over one third of the radiation scattered towards the surgeon. Use of robotic-guidance in a minimally invasive approach provided for a reduction of 62.5% of the overall radiation the surgeon was exposed to during open conventional approach. We conclude that reduced radiation use (e.g. by using robotic guidance) is a more effective strategy for minimizing exposure to radiation than reliance on protection by lead aprons, and recommend utilization of practices and technologies that reduce the surgical team's routine exposure to X-rays.

Comparison between percutaneous fluoroscopic-guided and conventional open pedicle screw placement techniques for the thoracic spine

Percutaneous placement of pedicle screws is a well-established technique, however, no studies have compared percutaneous and open placement of screws in the thoracic spine. The aim of this cadaveric study was to compare the accuracy and safety of these techniques at the thoracic spinal level. A total of 288 screws were inserted in 16 (eight cadavers, 144 screws in percutaneous and eight cadavers, 144 screws in open). Pedicle perforations and fractures were documented subsequent to wide laminectomy followed by skeletalisation of the vertebrae. The perforations were classified as grade 0: no perforation, grade 1: < 2 mm perforation, grade 2: 2 mm to 4 mm perforation and grade 3: > 4 mm perforation. In the percutaneous group, the perforation rate was 11.1% with 15 (10.4%) grade 1 and one (0.7%) grade 2 perforations. In the open group, the perforation rate was 8.3% (12 screws) and all were grade 1. This difference was not significant (p = 0.45). There were 19 (13.2%) pedicle fractures in the percutaneous group and 21 (14.6%) in the open group (p = 0.73). In summary, the safety of percutaneous fluoroscopy-guided pedicle screw placement in the thoracic spine between T4 and T12 is similar to that of the conventional open technique.

Cite this article: Bone Joint J 2015;97-B:1555–61.

Stentoplasty effectiveness and safety for the treatment of osteoporotic vertebral fractures: a systematic review

To assess the effectiveness and safety of stentoplasty in people with osteoporotic vertebral body fractures. A systematic search of databases including MEDLINE, EMBASE and Cochrane library, between others, was conducted to June 9, 2014. Clinical trials and observational studies that included alive adults with osteoporotic vertebral body fractures and the comparators were the intervention himself, vertebroplasty or balloon kyphoplasty were selected. Quality of evidence was graded according to the GRADE approach. Two review authors independently selected studies, assessed risk of bias and extracted data. Forty-two citations were identified during the search. After removing duplicates, five studies were included: two clinical trials and three observational studies. Stentoplasty, showed higher rate of adverse events related to material (P=0.043) and cuff pressure (P=0.014) in comparison to kyphoplasty. There was no difference between two procedures in terms of reduction of kyphosis, time of exposure to radiation or postoperative loss of cement. Stentoplasty in comparison to vertebroplasty, showed an improvement of restoration of vertebral height (P=0.042), kyphosis correction and volume of bone cement. No differences were found between two procedures in terms of loss of vertebral body volume. Based on observational studies, stentoplasty improved vertebral height, pain and functional disability at 6 and 12months follow-up, and corrected the angle vertebral fractures in patients with osteoporotic vertebral body. Stentoplasty was presented as a safe procedure in short-medium term, with a low complication rate, a reduced loss of cement and new vertebral body fractures lower rates. Stentoplasty improves vertebral height, reduces the pain and functional disability and correct the vertebral angle in patients with osteoporotic vertebral body fracture with minimum adverse events. Stentoplasty is comparable to kyphoplasty in terms of correction of kyphosis, time of exposure to radiation and cement postoperative loss, and comparable to vertebroplasty in terms of restoration of vertebral height correction and bone cement volume.

LEVEL OF EVIDENCE

Level II systematic review.

Eye lens monitoring for interventional radiology personnel: dosemeters, calibration and practical aspects of H p (3) monitoring. A 2015 review

A thorough literature review about the current situation on the implementation of eye lens monitoring has been performed in order to provide recommendations regarding dosemeter types, calibration procedures and practical aspects of eye lens monitoring for interventional radiology personnel. Most relevant data and recommendations from about 100 papers have been analysed and classified in the following topics: challenges of today in eye lens monitoring; conversion coefficients, phantoms and calibration procedures for eye lens dose evaluation; correction factors and dosemeters for eye lens dose measurements; dosemeter position and influence of protective devices. The major findings of the review can be summarised as follows: the recommended operational quantity for the eye lens monitoring is H p (3). At present, several dosemeters are available for eye lens monitoring and calibration procedures are being developed. However, in practice, very often, alternative methods are used to assess the dose to the eye lens. A summary of correction factors found in the literature for the assessment of the eye lens dose is provided. These factors can give an estimation of the eye lens dose when alternative methods, such as the use of a whole body dosemeter, are used. A wide range of values is found, thus indicating the large uncertainty associated with these simplified methods. Reduction factors from most common protective devices obtained experimentally and using Monte Carlo calculations are presented. The paper concludes that the use of a dosemeter placed at collar level outside the lead apron can provide a useful first estimate of the eye lens exposure. However, for workplaces with estimated annual equivalent dose to the eye lens close to the dose limit, specific eye lens monitoring should be performed. Finally, training of the involved medical staff on the risks of ionising radiation for the eye lens and on the correct use of protective systems is strongly recommended.

Percutaneous Minimally Invasive (MIS) Guide Wire-less Self-Tapping Pedicle Screw Placement in the Thoracic and Lumbar Spine: Safety and Initial Clinical Experience: Technical Note

BACKGROUND

Multiple methods for minimally invasive (MIS) thoracic and lumbar pedicle screw placement exist. The guide wire is almost universally used for most insertion techniques; however, its use is not without complication and potentially prolongs surgical procedures.

OBJECTIVE

To evaluate the safety of percutaneous MIS guide wire-less pedicle screw placement in the thoracic and lumbar spine at a single institution over a 3-year experience.

METHODS

Forty-one patients who underwent posterior instrumentation with 110 transpedicular MIS thoracic and lumbar screws by a single surgeon from 2011 to 2014 were analyzed. The mean age was 63 years at the time of surgery. Etiological diagnoses were adult spinal deformity, trauma, spondylosis/spondylolisthesis, and other spinal diseases. Pedicle screws were inserted with the use of a guide wire-free technique in which anatomy-specific entry sites and fluoroscopic landmarks were used to guide the surgeon. A square, sharp-tipped pedicle screw was carefully advanced under biplanar fluoroscopic image (anteroposterior and lateral) down the pedicle into the body. No tapping or any type of electromonitoring was performed. An independent spine surgeon using medical records and thoracic/lumbar computed tomography taken during the postoperative period reviewed all patients.

RESULTS

The number of the screws inserted at each level was as follows: total, 110; thoracic, 30; and lumbar, 80. All screws were evaluated by computed tomography to assess screw position. Seven screws (6.3%) were inserted with moderate cortical perforation, including 3 screws (2.7%) that violated the medial wall. There were no neurological, vascular, or visceral complications with up to 3 years of follow-up.

CONCLUSION

The percutaneous MIS guide wire-less technique of lumbar and thoracic pedicle screw placement performed using a biplanar fluoroscopic guidance in a stepwise, consistent manner is an accurate, safe, and reproducible method of insertion to treat a variety of spinal disorders.

Radiation safety and spine surgery: systematic review of exposure limits and methods to minimize radiation exposure

BACKGROUND

Ionizing radiation is typically used during spine surgery for localization and guidance in instrumentation placement. Minimally invasive (MI) surgical procedures are increasingly popular and often require significantly more fluoroscopy, placing surgeons at risk for increased radiation exposure and radiation-induced complications. This study provides recommendations for minimizing risk of radiation-induced injury to spine surgeons and summarizes studies addressing radiation exposure in spine procedures.

METHODS

The PubMed database was queried for relevant articles pertaining to radiation exposure in spine surgery.

RESULTS

Discectomy, percutaneous pedicle screw placement, MI transforaminal lumbar interbody fusion, MI lateral lumbar interbody fusion, and vertebroplasty/kyphoplasty procedures were assessed. The highest radiation doses were seen with MI pedicle screw placement, MI transforaminal lumbar interbody fusion, vertebroplasty and kyphoplasty, and percutaneous endoscopic lumbar discectomy. Use of lead aprons and thyroid shields reduces effective dose by several orders of magnitude. Proper operator positioning also minimizes radiation exposure. Lead gloves decrease dose to the surgeon's hand from scatter if the hand is out of the x-ray beam most of the time. If prolonged exposure of the hand cannot be avoided, the technician should collimate the surgeon's hand out of the beam or use instruments to position the hand farther from the beam. In addition to using less fluoroscopy, pulsed fluoroscopy can decrease overall dose in a procedure.

CONCLUSIONS

Spine surgeons should reduce their exposure to radiation to minimize risk of potential long-term complications. Strategies include minimizing fluoroscopy use and dose, proper use of protective gear, and appropriate manipulation of fluoroscopic equipment.

Significantly reduced radiation dose to operators during percutaneous vertebroplasty using a new cement delivery device

Background

Percutaneous vertebroplasy (PVP) might lead to significant radiation exposure to patients, operators, and operating room personnel. Therefore, radiaton exposure is a concern. The aim of this study was to present a remote control cement delivery device and study whether it can reduce dose exposue to operators.

Methods

After meticulous preoperative preparation, a series of 40 osteoporosis patients were treated with unilateral approach PVP using the new cement delivery divice. We compared levels of fluoroscopic exposure to operator standing on different places during operation. group A: operator stood about 4 meters away from X-ray tube behind the lead sheet. group B: operator stood adjacent to patient as using conventional manual cement delivery device.

Results

During whole operation process, radiation dose to the operator (group A) was 0.10 ± 0.03 (0.07-0.15) μSv, group B was 12.09 ± 4.67 (10–20) μSv. a difference that was found to be statistically significant (P < 0.001) between group A and group B.

Conclusion

New cement delivery device plus meticulous preoperative preparation can significantly decrease radiation dose to operators.

Robot-assisted vertebral body augmentation: a radiation reduction tool

STUDY DESIGN

Retrospective.

OBJECTIVE

To assess radiation exposure time during robot-guided vertebral body augmentation compared with other published findings.

SUMMARY OF BACKGROUND DATA

Rising incidence of vertebral compression fractures in the aging population result in widespread use of vertebral body cement augmentation with significant radiation exposure to the surgeon, operating room staff, and patient. Radiation exposure leads to higher cancer rates among orthopedic and spine surgeons and patients.

METHODS

Thirty-three patients with 60 vertebral compression fractures underwent robot-guided vertebral body augmentation performed by 2 surgeons simultaneously injecting cement at 2 levels under pulsed fluoroscopy. The age of patients was in the range from 29 to 92 (mean, 67 yr). One to 6 vertebrae were augmented per case (average 2). Twenty-five patients had osteoporotic fractures and 8 had pathological fractures. Robotic guidance data included execution rate, accuracy of guidance, total surgical time, and time required for robotic guidance. Radiation-related data included the average preoperative computed tomographic effective dose, radiation time for calibration, registration, placement of Kirschner wires, and total procedure radiation time. Radiation time per level and surgeon's exposure were calculated.

RESULTS

Kyphoplasty was performed in 15 patients (1 sacroplasty), vertebroplasty in 13, and intravertebral expanding implants in 5. The average preoperative computed tomographic effective dose was 50 mSv (18-81). Average operative time was 118 minutes (49-350). Mean robotic guidance took 36 minutes. Average operative radiation time was 46.1 seconds per level (33-160). Average exposure time of the surgeons and the operating room staff per augmented level was 37.6 seconds. The execution rate was 99%, with an accuracy of 99%. Two complications (hemothorax and superficial wound infection) occurred.

CONCLUSION

The radiation exposure of the surgeon and the operating room staff in a series of robot-assisted vertebral body augmentation was 74% lower than published results on fluoroscopy guidance and approximately 50% lower than the literature on navigated augmentation.

LEVEL OF EVIDENCE

4.

Patient radiation exposure during different kyphoplasty techniques

The scope of this study was to quantify patient radiation exposure during two different techniques of kyphoplasty (KP), which differ by a cement delivery method, in order to assess whether or not one of the two used methods can reduce the patient dose. Twenty patients were examined for this investigation. One X-ray fluoroscopy unit was used for localization, navigation and monitoring of cement delivery. The patient biometric data, the setting of the fluoroscope, the exposure time and the kerma-area product (KAP) were monitored in all the procedures for anteroposterior (AP) and lateral (LL) fluoroscopic projections in order to assess the range of radiation doses imparted to the patient. Theoretical entrance skin dose (ESD) and effective dose (E) were calculated from intraoperatively measured KAP. An average ET per procedure was 1.5±0.5 min for the manual injection technique (study A) and 1.4±0.4 min for the distance delivery technique (study B) in the AP plane, while 3.2±0.7 and 5.1±0.6 min in the lateral plane, respectively. ESD was estimated as an average of 0.10±0.06 Gy for study A and 0.13±0.13 Gy for study B in the AP or/and 0.59±0.46 and 1.05±0.36 Gy in the lateral view, respectively. The cumulative mean E was 1.9±1.0 mSv procedure(-1) for study A and 3.6±0.9 mSv procedure(-1) for study B. Patient radiation exposure and associated effective dose from KP may be considerable. The technique of distance cement delivery appears to be slower than the manual injection technique and it requires a more protracted fluoroscopic control in the lateral projection, so that this system entails a higher amount of dose to the patient.

Evaluation of the impact of a system for real-time visualisation of occupational radiation dose rate during fluoroscopically guided procedures

Optimisation of radiological protection for operators working with fluoroscopically guided procedures has to be performed during the procedure, under varying and difficult conditions. The aim of the present study was to evaluate the impact of a system for real-time visualisation of radiation dose rate on optimisation of occupational radiological protection in fluoroscopically guided procedures. Individual radiation dose measurements, using a system for real-time visualisation, were performed in a cardiology laboratory for three cardiologists and ten assisting nurses. Radiation doses collected when the radiation dose rates were not displayed to the staff were compared to radiation doses collected when the radiation dose rates were displayed. When the radiation dose rates were displayed to the staff, one cardiologist and the assisting nurses (as a group) significantly reduced their personal radiation doses. The median radiation dose (Hp(10)) per procedure decreased from 68 to 28 μSv (p = 0.003) for this cardiologist and from 4.3 to 2.5 μSv (p = 0.001) for the assisting nurses. The results of the present study indicate that a system for real-time visualisation of radiation dose rate may have a positive impact on optimisation of occupational radiological protection. In particular, this may affect the behaviour of staff members practising inadequate personal radiological protection.

Comparison of image quality and radiation exposure from C-arm fluoroscopes when used for imaging the spine

STUDY DESIGN

Cadaveric imaging study.

OBJECTIVE

We sought to compare the fluoroscopic images produced by 4 different fluoroscopes for image quality and radiation exposure when used for imaging the spine.

SUMMARY OF BACKGROUND DATA

There are no previous published studies comparing mobile C-arm machines commonly used in clinical practice for imaging the spine.

METHODS

Anterior-posterior and lateral images of the cervical, thoracic, and lumbar spine were obtained from a cadaver placed supine on a radiolucent table. The fluoroscopy units used for the study included (1) GE OEC 9900 Elite (2010 model; General Electric Healthcare, Waukesha, WI), (2) Philips BV Pulsera (2009 model; Philips Healthcare, Andover, MA), (3) Philips BV Pulsera (2010 model; Philips Healthcare, Andover, MA), and (4) Siemens Arcadis Avantic (2010 model; Siemens Medical Solutions, Malvern, PA). The images were then downloaded, placed into a randomizer program, and evaluated by a group of spine surgeons and neuroradiologists independently. The reviewers, who were blinded to the fluoroscope the images were from, ranked them from best to worst using a numeric system. In addition, the images were rated according to a quality scale from 1 to 5, with 1 representing the best image quality. The radiation exposure level for the fluoroscopy units was also compared and was based on energy emission.

RESULTS

According to the mean values for rank, the following order of best to worst was observed: (1) GE OEC > (2) Philips 2010 > (3) Philips 2009 > (4) Siemans. The exact same order was found when examining the image quality ratings. When comparing the radiation exposure level difference, it was observed that the OEC was the lowest, and there was a minimum 30% decrease in energy emission from the OEC versus the other C-arms studied.

CONCLUSION

This is the first time that the spine image quality and radiation exposure of commonly used C-arm machines have been compared. The OEC was ranked the best, produced the best quality images, and had the least amount of radiation.

2013 Young Investigator Award winner: how safe is lateral lumbar interbody fusion for the surgeon? A prospective in vivo radiation exposure study

STUDY DESIGN

Prospective in vivo radiation exposure study.

OBJECTIVE

To assess surgeon exposure to ionizing radiation in the setting of lateral lumbar interbody fusion (LLIF).

SUMMARY OF BACKGROUND DATA

Minimally invasive spine surgery relies heavily on image guidance. Rapid popularization of minimally invasive spine surgery procedures, such as LLIF, is appropriately accompanied by concern regarding occupational radiation exposure related to intraoperative fluoroscopy.

METHODS

Optically stimulated luminescence technology dosimeters were used to record radiation exposure prospectively at 5 anatomic locations during 18 LLIF procedures: (1) eye, (2) thyroid, (3) chest, (4) axilla, and (5) gluteal region. Additionally, a ring dosimeter was worn during 13 of the LLIF cases.

RESULTS

Average fluoroscopy time was 88.7 ± 36.8 seconds and skin dose to the patient was 25.2 ± 21.1 mGy. The chest dosimeter protected by lead recorded the lowest readings per procedure (0.44 ± 0.49 mrem). The gluteal dosimeter recorded an average exposure of 2.31 ± 4.50 mrem and the dosimeter at the axilla recorded an average of 4.20 ± 7.76 mrem per procedure. Exposure to the thyroid and eye were 2.19 ± 2.07 mrem and 2.64 ± 2.76 mrem, respectively. With the exception of the gluteal region, dosimeter readings from all unprotected areas were significantly higher than those from the chest dosimeter (P < 0.0125). In the course of 13 procedures, 190 mrem of exposure to the hand was recorded by the ring dosimeters. More than 2700 LLIF procedures may be performed annually before occupational limits are exceeded.

CONCLUSION

Prolonged exposure to "low-level" radiation as an occupational risk remains a concern for medical personnel. Radiation exposures to unprotected, radiosensitive locations, such as the axilla or eye, are worrisome. However, following radiation safety guidelines, 2700 LLIF procedures can be performed per year before exceeding occupational dose limits. Adherence to radiation safety guidelines is necessary to avoid sequelae related to an invisible but potentially deadly risk of minimally invasive spine surgery procedures.