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

Sunday, October 21, 2012: 10:27 AM
Melrose (Hilton Riverside)
Michael Sumko1, William Hennrikus, MD1, Jennifer Slough1, Kelly Jensen1, Douglas Armstrong1 and Steven King2, (1)Orthopaedics, Penn State College of Medicine, Hershey, PA, (2)Health Physics, Penn State College of Medicine, Hershey, PA

Purpose   Lee (JBJS 2011) reported that use of the mini c-arm in the ED can improve the quality and ED flow of pediatric fracture reductions  and decrease the radiation exposure to the patient and surgeon compared to plain radiographs. Lee estimated the radiation dose from the number of paper images that the resident printed and saved during the procedure.  Lee did not tabulate the number of fluoroscopic images taken during the entire reduction process. The purpose of this study is to report the amount of radiation 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  86 consecutive pediatric patients undergoing upper extremity fracture reduction in the ED were studied. The orthopedic resident, pgy2 or pgy3, performed manipulative reduction and casting of the fracture with use of the mini c-arm (Hologic Insight Fluoroscan, Inc.; Bedford, MA). Post-reduction, in cast, mini c-arm AP and lateral images 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 (SK) calculated the amount of millirem (mR) exposure for each reduction from this data.

Results  86 fracture reductions were studied during a 1 year period. 60 patients were males and 26 were female. The average age was 9 years old (range 1-16). 30 fractures (34%) involved the physis. 73 fractures (85%) involved the radius and or ulna, 6 (7%) were elbow fractures, 4 (5%) were hand fractures, and 3 (3%) were Monteggia fractures.  61 patients (71%) had commercial insurance; 22 patients (24%) had Medicaid; and 3 (4%) were self-pay. 79 patients (92%) were discharged home after the reduction. 7 patients (8%) were admitted: 2 (2%) for orthopedic fracture care in the OR and 5 (6%) for concomitant pediatric surgery care for additional injuries. The resident using the mini C arm and the fracture pattern affected the amount of radiation exposure. Less experienced PGY2 residents had a higher mR exposure per reduction compared to PGY3 residents. 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 AP/Lateral forearm radiographs emit an average of 20 mR.

Conclusion Radiation exposure when using the mini c-arm  for reduction of pediatric fractures has been under estimated in previous literature. In the present study, radiation exposure was not estimated but was accurately measured. Radiation from the mini C-arm exceeded that from conventional radiographs in most cases.  Training prior to use of the mini c-arm is imperative. 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.