Decreasing Radiation Exposure in the Treatment of Pediatric Long Bone Fractures Using a DXA Scan: A Proof of Concept

Abstract

Background: Fractures are typically evaluated and monitored using plain radiographs, but in the pediatric population the goal is always to reduce radiation exposure when possible. Dual-energy X-ray absorptiometry (DXA) is an imaging modality that uses less radiation. The evaluation of upper and lower extremity fractures in the pediatric population using DXA imaging has not yet been studied.Method: Radiographs of 19 patients treated for forearm or tibia fractures were compared to images taken with a DXA machine. The angulation and translation of the fractures were measured twice each by two independent observers. Correlation of these values between plain radiographs and DXA scans along with intra- and inter-observer reliability was calculated.Results: A total of 19 patients with a forearm or tibia fracture were enrolled in the study. Correlation with conventional radiographs for angulation was r=0.77, p<0.001, while for translation was r=0.76, p<0.001. The mean difference between the methods was 0.5 degrees (range of -6.7 to 7.7) for angulation and 4% (range of -28% to 37%) for translation. For plain radiographs the inter-rater reliability was 0.90 (95% confidence interval of 0.84-0.93) for angulation and 0.89 (0.68-0.95) for translation. The inter-rater reliability for DXA imaging was 0.77 (0.69-0.83) for angulation and 0.76 (0.41-0.88) for translation.Conclusion: Our study showed that DXA imaging correlates well with plain radiographs when measuring angulation and translation of forearm and tibia fractures in the pediatric population. This study is a proof of concept that DXA, a low-dose radiation alternative to plain radiographs, may be useful in the management of pediatric fractures.Level of Evidence: Level III Key Concepts•Decreasing radiation exposure in the pediatric population is an ongoing goal in pediatric orthopaedics.•Fracture follow-up imaging in the pediatric population currently is mainly restricted to plain radiographs.•A lower dose imaging modality might be an alternative to plain radiographs to monitor long bone fracture alignment.