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

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 (DEXA) is an imaging modality that uses less radiation. The evaluation of upper and lower extremity fractures in the pediatric population using DEXA imaging has not yet been studied. Method: Radiographs of 19 patients treated for forearm or tibia fractures were compared to images taken with a DEXA machine. The angulation and translation of the fractures were measured twice each by two independent observers. Correlation of these values between plain radiographs and DEXA 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 it 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 DEXA imaging was 0.77 (0.69-0.83) for angulation and 0.76(0.41-0.88) for translation. Conclusion: Our study showed that DEXA 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 DEXA, a low-dose radiation alternative to plain radiographs, may be useful in the management of pediatric fractures.