Dose reduction for minimizing radiation in displaced paediatric supracondylar humerus fractures: single vs. automated pulse mode

Abstract

Conventional C-arm image intensifiers (CCA) are an essential and indispensable aid in modern orthopaedic surgery. CCAs are defaulted to auto-pulse mode which emit multiple pulses (or bursts) of radiation to obtain optimum image quality. The number of pulses per shot can be configured manually. The purpose of this study is to investigate the efficacy of the single pulse mode of CCA in reducing and fixing paediatric supracondylar humeral fractures (SCHF). A retrospective chart review of 99 paediatric patients who underwent closed reduction and percutaneous pinning of displaced SCHF was performed. Fifty-one consecutive cases operated with auto-pulse mode (group A). Another 48 consecutive cases were operated with the single-pulse mode (group B). Baumann's angle, operative duration and average radiation dose rate were recorded for comparison between both groups. Twenty postpinning images were randomly selected (10 from each group) to study intra- and interobserver reliability. Twelve doctors were recruited and tasked to identify if each X-ray was taken with the auto-pulse or single-pulse mode. This was repeated after 2 weeks. The patients in the auto-pulse mode group had a significantly higher mean radiation dose of 40.4 ± 32.51 cGycm2/min compared to that of 14.8 ± 3.24 cGycm2/min for the single-pulse group (P ≤ 0.001). All patients in both groups had Baumann's angle within normal range of 64-81°. No significant difference was noted in average intraoperative timings between both groups (P = 0.869). In the majority of cases, the doctors were unable to visually differentiate between the modes of CCA used. The single-pulse mode is an excellent alternative to the auto-pulse mode in fixing SCHF. It gives significantly lower radiation without compromising the surgical outcome. Level of evidence: Level III retrospective comparative study.