ORIGINAL ARTICLE

Measurement of Radiation Exposure When Using the Mini C-Arm to Reduce Pediatric Upper Extremity Fractures Michael J. Sumko, DO, William Hennrikus, MD, Jennifer Slough, MD, Kelly Jensen, DO, Douglas Armstrong, MD, Stephen King, PhD, and Kenneth Urish, MD

Background: Previous literature has underreported radiation exposure with the use of mini C-arm during pediatric forearm fracture reductions. The purpose of this study is to report an accurate amount of radiation exposure during fracture reductions using a mini C-arm that records the amount of kilovolts, milliamps, and the number of seconds of foot pedal use. Methods: Eighty-six consecutive pediatric patients undergoing upper extremity fracture reduction in the emergency department were studied. The orthopaedic resident, either a PGY2 or PGY3, performed a manipulative reduction and casting of the fracture with use of the mini C-arm. Postreduction, in cast, anteroposterior and lateral images from the mini C-arm were saved to the computerized radiology system. The mini C-arm recorded the amount of kilovolts, milliamps, and the number of seconds that the foot pedal was used for each reduction. A radiology physicist (S.K.) calculated the amount of millirem (mR) exposure for each reduction from these data. Results: The resident using the mini C-arm and the fracture pattern affected the amount of radiation exposure. The average mini C-arm mR exposure for distal radius fractures was 63 mR; forearm 109 mR; elbow 53 mR; and hand 69 mR. For comparison, conventional anteroposterior/lateral forearm radiographs emit an average of 20 mR. Less-experienced PGY2 residents had a higher mR exposure per reduction compared with PGY3 residents. Conclusions: Radiation exposure when using the mini C-arm for reduction of pediatric fractures has been underestimated in previous literature. Radiation from the mini C-arm exceeded that from conventional radiographs in most cases. We recommend that residents receive training about the use of the mini Carm before its utilization as an aid to reduce pediatric fractures in the emergency department. Level of Evidence/Clinical Relevance: Prospective study to evaluate the total amount of radiation exposure per pediatric forearm fracture reduction. Key Words: radiation exposure, mini C-arm, pediatric forearm fractures, pediatric fracture reductions (J Pediatr Orthop 2016;36:122–125) From the Penn State College of Medicine, Hershey, PA. The authors declare no conflicts of interest. Reprints: Michael J. Sumko, DO, Penn State College of Medicine, 30 Hope Drive, Hershey, PA 17033. E-mail: [email protected] Copyright r 2015 Wolters Kluwer Health, Inc. All rights reserved.

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ee et al1 reported that use of the mini C-arm in the emergency department (ED) can improve the quality of pediatric fracture reduction, decrease the need for repeat reductions, decrease orthopaedic consultation time, and decrease the radiation exposure to the patient and surgeon in comparison with plain radiographs. Lee and colleagues estimated the radiation dose for each reduction from the number of paper images that the resident printed and saved during the fracture reduction. Lee and colleagues did not tabulate the number of actual fluoroscopic images used throughout the entire reduction process. The purpose of this study is to report an accurate amount of radiation exposure during fracture reductions using a mini C-arm that records the amount of kilovolts, milliamps, and the number of seconds of foot pedal use.

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METHODS The Penn State College of Medicine IRB approved this study. Eighty-six consecutive pediatric patients undergoing upper extremity fracture reduction in the ED were studied. The fractures were reduced using conscious sedation that was administered and monitored by the ED physician and nurse. We did not measure the quality of sedation. All residents were supervised by an attending orthopaedic Surgeon. A PGY2 or PGY3 orthopaedic resident performed manipulative reduction and casting of the fracture with the use of mini C-arm (Hologic Insight Fluoroscan Inc., Bedford, MA). We did not measure how many reductions the resident attempted. We have a policy of no more than 3 reduction attempts, otherwise the patient is brought to the operating room for reduction. Postreduction, in cast, anteroposterior (AP) and lateral images from the mini C-arm were saved to the computerized radiology system. The mini C-arm recorded the amount of kilovolts, milliamps, and the number of seconds that the foot pedal was used for each reduction. A radiology physicist (S.K.) calculated the amount of millirem (mR) exposure for each reduction from these data.2 Statistical analysis was performed with data expressed as a mean ± 95% confidence interval, except where noted. Multiple group comparisons were made using 2-way unbalanced mixed population ANOVA, using the Tukey post hoc analysis to determine significance J Pediatr Orthop



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Radiation Exposure When Using the Mini C-Arm

levels. To control for multiple comparisons, the Bonferroni correction was used to confirm results. All statistical tests were completed using R (R Core Development Team, http://www.r-project.org).

RESULTS Eighty-six fracture reductions were studied during a 1-year period. Sixty patients were male and 26 female. The average age was 9 years (range, 1 to 16 y). Thirty fractures (34%) involved the physis. Seventy-three fractures (85%) involved the radius and or ulna, 6 (7%) were elbow fractures, 4 (5%) were hand fractures, and 3 (3%) were Monteggia fractures. Nine patients (10%) were transferred from an outside hospital ED for their reduction. Seventy-nine patients (92%) were discharged home after the reduction. Seven patients (8%) were admitted: 2 (2%) for orthopaedic fracture care in the OR and 5 (6%) for concomitant pediatric surgery care for additional injuries. Eighty-four cases (97%) had a successful fracture reduction. The resident using the mini C-arm and the fracture pattern affected the amount of radiation exposure. The average mini C-arm mR exposure for distal radius fractures was 63 mR; forearm 109 mR; elbow 53 mR; and hand 69 mR (Fig. 1). For comparison, conventional AP/lateral forearm radiographs emit an average of 20 mR. Less-experienced PGY2 residents had a higher mR exposure per reduction compared with PGY3 residents (Fig. 2; P < 0.01). Fracture reductions were performed from 5 PM to midnight in 53 cases (62%); from 7 AM to 5 PM in 28 cases (32%); and from midnight to 7 AM in 5 cases (6%). Reductions were most common in September (19 cases) and least common in February (3 cases).

DISCUSSION Lee et al3 in 1994 first reported that the use of mini C-arm is safe and effective for management of distal extremity fractures and led to “increased effectiveness in reduction.” Sharieff et al4 in 1999 reported that portable fluoroscopic images can replace postreduction radiographs in the management of pediatric fractures. Lee et al1 in 2011 recently reported that use of mini c-arm fluoroscopy improves quality of the reduction, decreases the need for repeat fracture reduction or additional procedures, decreases orthopaedic consultation time, and decreases the radiation exposure. We agree with Lee and colleague’s conclusions in his 2011 paper except for his finding that the amount of radiation exposure is reduced by use of mini C-arm. The focus of this article is to accurately report radiation exposure from the mini C-arm when reducing pediatric upper extremity fractures in the ED. For example, the current study contradicts Lee and colleague’s findings that using the mini C-arm for ED fracture reductions reduces radiation exposure to the patient and the surgeon. Lee and colleagues suggested that the radiation dose in his study may have been unCopyright

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FIGURE 1. Average millirem (mR) exposure from mini C-arm per reduction for both PGY2 and PGY3 combined. Traditional anteroposterior (AP)/lateral x-rays; forearm/humerus: 10 mR for each view = 20 mR for AP and lateral views; elbow: 12 mR for each view = 24 mR for AP and lateral views; hand: 8 mR for each view = 16 mR for AP and lateral views.

derestimated as it was calculated from the number of images that the orthopaedic residents choose to print out during fracture reduction. The residents in Lee and colleague’s study were instructed to print preliminary and final reduction images. Lee et al’s1 paper did not tabulate the number of actual fluoroscopic images used throughout entire reduction process. In contrast, the current study measured the radiation exposure to the patient and surgeon accurately by recording the amount of kilovolts, milliamps, and the number of seconds of foot pedal use for each reduction. The average radiation exposure measured using the mini C-arm using this methodology was up to 4 times that of standard flat plate AP and lateral views. For example, radiation exposure for a flat plate x-ray in our institution is 10 mR for an AP forearm and 10 mR for a lateral forearm. In the current study, the radiation exposure using the mini C-arm for a forearm reduction was 76 mR—almost 4 times the mR from a combined AP and lateral postreduction flat plate x-ray. Similarly, the average radiation exposure for flat plate x-rays of the elbow is 12 mR for each view and 8 mR for each hand view. Conversely, the average mini C-arm radiation exposure when reducing a distal radius fracture was 63.1 mR, elbow fractures 40.4 mR, hand fracture 69 mR, and distal humerus fractures 86 mR. A new and important finding in the current study was that the radiation exposure to the patient and www.pedorthopaedics.com |

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using the mini C-arm, the average radiation dose to the surgeon’s whole body was 800 mR and to the surgeon’s extremities was 8500 mR. Shoaib et al7 reported that the mini C-arm minimized radiation scatter to the surgeon compared with a conventional C-arm, however, the overall radiation exposure to the patient’s limb that was directly in line with the x-ray beam was similar with either machine. Similarly, Giordano et al8 reported that the only major exposure to radiation when using a mini C-arm was directly in the path of the radiation beam. In addition, Lee et al1 estimated that if a surgeon stood 1 m from the mini C-arm intensifier for 2 hours daily he/she would not reach half of the maximum permissible dose allowed. In the current study, if a PGY2 resident performed 50 forearm fracture reductions per year using the mini Carm, he/she would accumulate about 5000 mR of exposure reaching the recommended annual body limit. Each resident in the current study performed an average of 13 forearm reductions per year. We recommend, and have established at our hospital, an annual symposium for surgeons/residents about radiation safety and the use of the mini C-arm. FIGURE 2. Comparison of average millirem (mR) exposure from mini C-arm per reduction for both PGY2 and PGY3. P < 0.05; traditional anteroposterior (AP)/lateral x-rays; forearm/ humerus: 10 mR for each view = 20 mR for AP and lateral views; elbow: 12 mR for each view = 24 mR for AP and lateral views; hand: 8 mR for each view = 16 mR for AP and lateral views.

surgeon decreased significantly when comparing resident training level PGY2 and PGY3 (P < 0.01). We suspect that this finding is due to the PGY3 residents having more experience reducing fractures using the mini C-arm. This experience includes the skill of reduction, technique of using the mini C-arm, minimizing pedal time, and improved ability to shoot perfect orthogonal views. The finding that junior residents utilize more radiation during a fracture reduction reinforces our recommendation that all physicians, especially less-experienced PGY2 residents, should undergo training before use of the mini C-arm. In addition to our annual orthopaedic boot camp on fracture care and reductions, we have instituted a 2-hour annual radiation safety symposium in our department for this purpose. How much radiation is unhealthy for the surgeon? The National Council on Radiation and Management standards reports that the average mR exposure per year per human is 620 mR (http://www.new.ans.org). Most of this radiation stems from the environment and the remainder from medical tests. The recommended annual maximum dose limit of radiation to the whole body is 5000 mR, and the annual maximum dose limit of radiation to the extremities is 50,000 mR.5 Tuohy et al6 reported that in a hand surgery practice with each of 4 surgeons wearing lead and performing 50 cases per year

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CONCLUSIONS Use of the mini C-arm for pediatric fracture reductions in the ED is standard practice at many hospitals. While the mini C-arm improves reduction quality, decreases the need for repeat reductions, minimizes orthopaedic consult time, and improves patient through put, radiation exposure can exceed that of 1 set of conventional radiographs. Radiation exposure when using the mini c-arm for reduction of pediatric fractures has been underestimated in previous literature. In the present study, radiation exposure was not estimated but was accurately measured. Radiation exposure using the mini Carm was related to the in-experience of the physician performing the reduction. Mandatory training before use of the mini C-arm varies from state to state. Although Pennsylvania currently has no requirements, we believe it is imperative to receive training before use. Because of the results of this study, the Orthopaedic Department in collaboration with the Radiology Department has instituted an annual course on radiation safety and mini Carm use for all orthopaedic residents and faculty. Lead aprons should be worn by the patient, the physician, and any family members nearby when using the mini C-arm in the ED for pediatric fracture reductions. We recommend that all physicians and residents receive annual training about radiation safety and proper use of the mini C-arm. Specific training about foot pedal time, number of exposures needed, positioning the limbs for AP and lateral images, is recommended. REFERENCES 1. Lee MC, Stone NE III, Ritting AW, et al. Mini-C-arm fluoroscopy for emergency-department reduction of pediatric forearm fractures. J Bone Joint Surg. 2011;93A:1442–1447. 2. Kings S. Radiologist Physicist, Milton Hershey Medical Center, Hershey, PA.

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3. Lee SMK, Orlinski M, Chan LS. Safety and effectiveness of portable fluoroscopy in the emergency department for the management of distal extremity fractures. Ann Emerg Med. 1994;24:725–730. 4. Sharieff GQ, Kanegaye J, Wallace CD, et al. Can portable bedside fluoroscopy replace standard, post reduction radiographs in the management of pediatric fractures? Pediatr Emerg Care. 1999;15: 249–251. 5. The National Council on Radiation and Management. Available at: http://www.new.ans.org. Accessed May 2012.

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Radiation Exposure When Using the Mini C-Arm

6. Tuohy CJ, Weikert DR, Watson JT, et al. Hand and body radiation exposure with use of the mini C-arm fluoroscopy. J Hand Surg. 2011;36A:632–638. 7. Shoaib A, Rethnam U, Bansal R, et al. A comparison of radiation exposure with the conventional versus mini C-arm in orthopedic extremity surgery. Foot Ankle Int. 2008;29:58–61. 8. Giordano BD, Ryder S, Baumhauer JF, et al. Exposure to direct and scatter radiation with use of mini c-arm fluoroscopy. J Bone Joint Surg Am. 2007;89:948–952.

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Measurement of Radiation Exposure When Using the Mini C-Arm to Reduce Pediatric Upper Extremity Fractures.

Previous literature has underreported radiation exposure with the use of mini C-arm during pediatric forearm fracture reductions. The purpose of this ...
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