Effects of obtaining plain radiographs in pediatric patients with radial head subluxation
Article information
Abstract
Purpose
This study investigated the rate and factors of spontaneous reduction (SR) during plain radiography in pediatric patients with radial head subluxation (RHS).
Methods
We retrospectively reviewed patients aged 5 years or younger with RHS who visited a tertiary hospital emergency department (ED) from March 2015 through February 2022. They were classified into the SR during X-ray, manual reduction (MR) after X-ray, and MR-first groups. We compared the clinical variables, such as ED length of stay, among the 3 groups, and investigated factors associated with SR during radiography.
Results
Among a total of 550 enrolled patients, 153 (27.8 %), 177 (32.2%), and 220 (40.0%) belonged to the SR during X-ray, MR after X-ray, and MR-first groups, respectively. Among the groups, no difference was found in the proportions of indoor injury (SR during X-ray, 92.6% vs. MR after X-ray, 79.0% vs. MR-first, 89.0%; P = 0.066). The mean ED length of stay was shorter in the MR-first group than in the equivalent values of the other groups (23.1 minutes vs. 49.0-53.0 minutes; P < 0.001), without differences in the other time intervals. The sole factor associated with SR during radiography was the indoor injury (odds ratio, 3.32; 95% confidence interval, 1.01-10.88; P = 0.048).
Conclusion
Based on the results of this study, emergency physicians or pediatricians might consider obtaining radiographs first in patients with RHS injured indoors, which can cause SR and exclusion of complications such as iatrogenic injury.
Introduction
Radial head subluxation (RHS) may be reduced in the process of plain radiography. Specifically, during the process of shifting from external oblique to internal oblique positions, the forearm is hyper-pronated, which may reduce RHS. Radiography is also useful for excluding fractures, minimizing the occurrence of iatrogenic injury during manual reduction (MR) (1,2). There have been reported cases where RHS is spontaneously reduced during radiography (3). For example, in an emergency department (ED) in New Jersey, spontaneous reduction (SR) rates were similar between RHS patients with and without classic injury mechanism: 5 of the 30 patients vs. 2 of the 15 patients, respectively (4). In contrast, performing radiography can increase ED length of stay (EDLOS), compared to performing MR without radiography. To the author’s knowledge, there has been a lack of studies comparing the benefits of performing radiography first and MR first in patients with RHS. Therefore, in this population, we compared the clinical variables, and factors associated with SR during radiography, as per whether the patients underwent radiography first or MR first.
Methods
1. Study design and population
This retrospective study was performed in patients aged 5 years or younger who visited a tertiary hospital ED with RHS from March 2015 through February 2022. Data used in this study were anonymized before analysis. This study was performed in accordance with the Declaration of Helsinki and approved by the institutional review board with a waiver for informed consent (IRB no. UUH-IRB-2023-04-004).
Emergency physicians assigned the Korean Standard Classification of Diseases diagnostic code of RHS (S53.0W1) to patients with probable RHS. The probable RHS case was defined as follows: axial traction on the extended arm (5-7); holding the affected arm close to the body and trying to avoid moving it at ED presentation; sudden and severe elbow, wrist, or shoulder pain (8,9); or difficulty in moving the arm without tenderness, swelling, or elbow deformity (10). We excluded the cases of unknown injury mechanisms.
2. Group designation and outcomes
The patients were grouped as follows: those who underwent MR without or prior to radiography (MR-first group) and the others who underwent radiography prior to MR. The latter group was further classified into those who underwent SR during radiography (SR during X-ray group) and those who underwent MR after radiography (MR after X-ray group). SR was defined as a full recovery from pain or limited range of motion without MR. The outcomes of interest were the proportion of SR during radiography, EDLOS, and factors associated with SR. The performed radiography typically consisted of anteroposterior, lateral, external oblique, and internal oblique views. It usually took 20-30 minutes for the emergency physicians to perform the radiography and interpret the radiographs.
3. Variables and measurement
Medical records were reviewed in terms of the following variables: age, sex, right-sided lesion, injury due to fall, indoor injury, activity during injury, and EDLOS. The indoor location of injury included home, restaurant, school, or theater. The activity during injury was regarded as active if the injury occurred during running, riding a bicycle, or hanging onto a bar. The EDLOS was divided into the arrival-to-X-ray time and X-ray-to-discharge time.
4. Statistical analysis
Comparisons among the 3 groups were performed using Pearson’s chi-square or Fisher’s exact tests. In addition, EDLOS was compared by analysis of variance, post hoc, and Tukey’s multiple comparison tests. The normality of the distribution of all variables was tested using the Kolmogorov-Smirnov tests, and all variables were normally distributed. Bonferroni corrections were conducted to reduce type 1 error. Univariate logistic regression analysis of the patients’ general characteristics was performed to identify the factors associated with SR during radiography. IBM SPSS software for Windows ver. 24.0 (IBM Corp.) was used for the statistical analyses. A P < 0.05 was defined as statistically significant.
Results
Among a total of 550 enrolled patients, 330 (60.0%) underwent radiography first, of whom 153 patients (27.8%) underwent SR during radiography (Fig. 1). Of the 220 patients underwent MR first, 211 underwent radiography after the MR. There were no differences in the mean age and proportions of boys, right-sided lesion, indoor injury, or activity during injury (Table 1). Fall was more frequently observed in the SR during X-ray and MR after X-ray groups, compared with in the MR-first group. The MR-first group showed a mean EDLOS (23.1 minutes), which was shorter than the equivalent values of the other 2 groups (49.0-53.0 minutes; P < 0.001), without differences in the other time intervals. The sole factor associated with SR during radiography was the indoor location of injury (Table 2).
Flow chart of the study population. RHS: radial head subluxation.
Characteristics of patients who visited the emergency department for radial head subluxation, sorted by treatment process
Factors related to spontaneous reduction after obtaining radiographs for radial head subluxation
Discussion
In this study, the rates of SR during radiographic examination and several other factors about RHS patients were studied. This study was conducted to see if the position changes during obtaining radiographs could replace MR, and SR occurred in 46.4% (153 of the 330 patients) of the groups who obtained radiographs.
Many studies have been conducted on RHS over a long time. Although females were more affected than males in previous studies (5), it is unclear if there are relevant sex-specific behavioral differences or anatomic factors (11). In contrast, no significant sex differences were found in another study (12). In our study, there were no significant differences between the sexes. In another study, RHS more commonly occurred on the left side because many adults held children’s left hands with their right hands (12), in contrast to the absence of difference in the left-right proportions in our study. This disparity might be related to factors other than the holding guardians’ handedness, such as contusion, falling, or sprain.
In a relevant study, the median time in RHS patients from triage to ED discharge was 1.7 hours (13). The value is longer than the mean EDLOS of 39.9 ± 30.0 minutes in our study (Table 1). There was no difference in the mean EDLOS between the SR during X-ray and MR after X-ray groups, despite the nonperformance of MR in the former group. This might be due to the difference in the observation time for recovery. In the MR-first group, emergency physicians or pediatricians could check for the clunk, which indicates a reduction of RHS (8). Given the inability to check the sign in the SR during the X-ray group and the consequent uncertainty regarding the outcomes of reduction, a post-reduction observation time could be longer in the group than in the MR-first group. The shortest mean EDLOS in the MR-first group was probably owing to not obtaining radiographs.
In this study, 46.4% of the patients underwent SR during performing radiography. In patients with atypical presentation of RHS, radiography was recommended to exclude other diagnoses (5-7) given that 1%-5% may have diagnoses such as a supracondylar humeral fracture (14-16). In addition, delayed treatment of RHS can interfere with MR and promote synovitis (13,16). Therefore, in patients with probable RHS, obtaining radiographs prior to MR may be useful in minimizing the occurrence of misdiagnosis or complications. In tertiary hospitals in Korea, milder diagnoses rated per the Korean Triage and Acuity Scale are less covered by the National Health Insurance Service, compared with more severe diagnoses (17). Most RHS patients are classified as the Korean Triage and Acuity Scale level 4, a non-emergency. Our hospital charges 53.7 USD as reception fee for a non-emergency, 9.5 USD for the elbow series radiographs fee, and 46.7 USD for the MR fee at the time of writing. Considering the higher reception fee and fewer insurance benefits for non-emergency cases, obtaining radiographs for patients with RHS is relatively inexpensive and useful to minimize misdiagnosis or complications, and can substitute MR in 46.4%.
As shown in Table 2, the occurrence of indoor injury was associated with the SR during radiography. Considering the lower energy and slower velocity of indoor activities relative to outdoor activities, cases of RHS that occurred indoors may result in a milder subluxation than those that occurred outdoors. This feature may explain the significant association between the indoor location and SR during radiography.
The limitations of this study are as follows. First, given the retrospective nature, it was difficult to collect sufficient clinical information, such as the mechanism of injury, from medical records. Second, it was difficult to compute the observation time to confirm SR given the lack of recommendation of the observation. Because it was difficult to clearly determine the loss of symptoms in the patients whose mean age was 2.0 ± 1.2 years, the SR rate did not reflect the actual value. Third, some diagnosis of RHS was erroneously given due to the subjectiveness of diagnostic criteria.
The results of this study can be useful for prioritizing MR or radiography in managing patients with RHS in EDs. Approximately half of the RHS patients obtaining radiographs were spontaneously reduced during radiography in the ED. In particular, an indoor injury was associated with SR during radiography. Therefore, emergency physicians or pediatricians might consider obtaining radiographs first in patients with RHS injured indoors. This practice pattern may induce SR during the process of radiography while minimizing the occurrence of misdiagnosis or complications.
Notes
Author contributions
Conceptualization: all authors
Data curation, Investigation, Resources, Software, Supervision, and Visualization: JH Kang
Formal analysis, Funding acquisition, and Project administration: JH Kang and JS Hwang
Methodology: JH Kang and R Ahn
Validation: R Ahn and JS Hwang
Writing-original draft: JH Kang
Writing-review and editing: all authors
All authors read and approved the final manuscript.
Conflicts of interest
No potential conflicts of interest relevant to this article were reported.
Funding sources
No funding source relevant to this article was reported.
Data availability
The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.
Acknowledgements
This work was supported by the Big Data Center of Ulsan University Hospital for statistical analysis.