Abstract
Background:
Reduction of pediatric forearm fractures with the patient under sedation in the emergency department is a common practice throughout the United States. We hypothesized that the use of a mini-c-arm fluoroscopy device as an alternative to routine radiographs for evaluation of fracture reduction would (1) allow a more anatomic fracture reduction, (2) decrease the number of repeat reductions or subsequent procedures, (3) reduce overall radiation exposure to the patient, and (4) decrease the orthopaedic consultation time in the emergency department.
Methods:
A retrospective cohort analysis of 279 displaced forearm and wrist fractures treated with closed reduction and casting with the patient under sedation in the emergency department of a level-I pediatric trauma center was performed, and the data were compared with historical controls. One hundred and thirteen fracture reductions were assessed with a mini-c-arm device, and 166 fracture reductions were evaluated with radiographs. All patients had radiographs of the injury. Blinded, independent reviewers graded the quality of reduction for residual angulation and translation of the reduced fracture. Radiation exposure was determined by the average number of radiographs made through either modality. Emergency department and outpatient charts were reviewed to determine the total orthopaedic consultation time and the need for repeat reductions or operative intervention.
Results:
Pediatric forearm fractures undergoing closed reduction with assistance of the mini c-arm had a significant improvement in reduction quality (average angulation [and standard deviation], 6° ± 4° vs. 8 ± 6°; p = 0.02), a decrease in repeat fracture reduction and need for subsequent operative treatment (two [2%] of 113 fractures vs. fourteen [8.4%] of 166 fractures; p ≤ 0.0001), and a decrease in radiation exposure to the patient (mean, 14.0 ± 10.3 mrem vs. 50.0 ± 12.7 mrem). The average orthopaedic consultation time was decreased with use of a mini c-arm (28 ± 12 min vs. 47 ± 19 min, p < 0.001).
Conclusions:
Use of the mini c-arm to assist in the closed reduction of pediatric forearm and wrist fractures in the emergency department can improve the quality of the reduction, decrease the radiation exposure to the patient, and decrease the need for repeat fracture reduction or additional procedures. Mini-c-arm imaging can also decrease the average orthopaedic consultation time for fracture reduction.
Level of Evidence:
Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.
Pediatric forearm and wrist fractures are common and account for approximately 30% to 50% of all pediatric fractures1-6. Emergency department management of displaced forearm and distal radial and/or ulnar fractures in children typically begins with radiographs to confirm and characterize the fracture. If the fracture pattern and patient comorbidities permit, and if no neurovascular compromise or soft-tissue disruption is identified, the patient is sedated and a closed reduction is performed with the application of a well-molded cast. Radiographs are then made to evaluate the quality of the fracture reduction.
Mini-c-arm fluoroscopy, or portable fluoroscopy, offers theoretical advantages to traditional radiographs in the emergency department. Mini-c-arm use allows a rapid evaluation of the fracture position immediately during and after the reduction procedure and may expedite patient care while decreasing the total duration of sedation and number of sedation sessions required to achieve an acceptable reduction. As a result of such potential benefits, many emergency departments throughout the country have adopted mini-c-arm technology.
However, as far as we know, no good clinical evidence has been reported to support the assumption that the mini c-arm improves overall clinical fracture care. Although previous work has shown that postreduction mini-c-arm fluoroscopic images can replace routine postreduction radiographs for distal radial and/or ulnar fractures in assessing fracture alignment, no study, to our knowledge, has demonstrated whether fracture alignment is clinically improved by using fluoroscopy compared with radiography for evaluation of fracture reductions6. Despite past work that suggests a mini c-arm can reduce total radiation exposure to the patient for fracture reduction, the data have been mostly accrued through mathematical or cadaver models2,7,8. There remain little clinical data demonstrating that fracture reductions with a mini c-arm in the emergency department result in a lower dose of radiation to the patient compared with reductions assessed with radiographs. Other suggested but unproven benefits of mini-c-arm fluoroscopy include decreasing the total number of repeat fracture reduction procedures and decreasing the overall time spent by the patient in the emergency department.
This study aimed to explore the theoretical advantages of mini-c-arm fluoroscopy use in the care of pediatric forearm fractures in an emergency department setting. Specifically, we hypothesized that a mini-c-arm fluoroscope used for the reduction of pediatric forearm fractures would (1) improve the fracture alignment to a more anatomic position, (2) decrease the number of repeat reductions or subsequent surgical interventions to treat the fracture, (3) reduce overall radiation exposure to the patient, and (4) decrease the patient time in the emergency department.
A retrospective cohort analysis with historical controls was performed following approval by the institution's investigational review board. All pediatric patients with displaced or angulated diaphyseal forearm or distal radial and/or ulnar fractures presenting to a single level-I trauma center between October 2001 and December 2002 composed the cohort group. The cohort group underwent a common protocol of initial radiographs to assess fracture reduction, conscious sedation for performance of the fracture reduction, and use of mini-c-arm fluoroscopy (700-msec snapshot mode, OEC MiniView 6800; General Electric, Salt Lake City, Utah) for evaluation of the reduction in or out of the final cast. If the reduction was judged inadequate, the fracture was remanipulated under fluoroscopy while the patient remained sedated. Images made with the mini c-arm were printed and stored in the patient's chart.
The historical control group of the study consisted of a consecutive series of patients evaluated between January 1998 and August 2001 in the same level-I trauma center, prior to the availability of mini-c-arm fluoroscopy. In the control group, patients had initial injury radiographs, conscious sedation for fracture reduction, and a radiograph made after reduction to assess fracture alignment. If fracture alignment was not acceptable, the patient would undergo additional rounds of sedation, reduction, and radiographs until the reduction was judged acceptable.
Inclusion criteria for both groups included forearm shaft fractures, distal radial fractures, or combined distal radial and distal ulnar fractures, with an angulation of ≥10°, in patients between one and sixteen years of age who underwent reduction with sedation. Exclusion criteria for both groups included open fractures, intra-articular fractures (i.e., Salter-Harris type-III or IV fractures9), fractures with neurovascular compromise, supracondylar or other fractures involving the elbow, distal radioulnar joint or elbow dislocations, irreducible fractures requiring immediate surgical treatment, critically ill patients, and patients requiring emergency computed tomography (CT) scanning. Fracture reductions were performed by third-year orthopaedic residents working without the immediate supervision of an attending physician. Conscious sedation was performed by attending physicians in the emergency department, using midazolam and fentanyl with established monitoring protocols10.
Demographic data were obtained from patient charts. Patients were followed up for three months after the reduction in the emergency department. Radiographs made before the reduction and radiographs or printed mini-c-arm images made after the reduction were evaluated for fracture angulation and translation, calculated as a percentage of shaft width. Radiographic images were reviewed by three pediatric orthopaedic attending surgeons blinded to the patient group, and the maximum fracture translation and angulation determined by the reviewers was used. The total number of reduction radiographs or printed mini-c-arm images for each patient was tabulated. The number of additional treatments, such as repeat reductions in the emergency department, additional reductions as an outpatient, or procedures in the operating room for repeat reduction or fracture fixation, was identified through a review of emergency department and outpatient charts. The patient's total time in the emergency department, as well as the duration of the orthopaedic consultation, inclusive of time for reduction radiographs, was also obtained from patient charts.
A broad range of acceptable closed reduction parameters for pediatric patients with fractures of the radial and ulnar shafts or the distal ends of the radius and ulna was used, consistent with published values. In particular, patients younger than nine years of age were allowed 15° of angulation, 45° of malrotation, and complete bayonet apposition for any level of radial and ulnar shaft fracture. In those older than nine years of age, middle and proximal one-third fractures were allowed 10° of angulation and 30° of malrotation, while distal one-third fractures were allowed 15° of angulation and bayonet apposition as long as there was at least two years of growth potential4. Metaphyseal distal radial and ulnar fractures were allowed an even wider range of acceptability, with 30° of sagittal and 20° of coronal plane angulation allowed in patients nine years of age or younger. In older children with at least one year of growth remaining, 20° of sagittal and 15° of coronal plane angulation were permitted11.
Radiation exposure estimates for each radiograph and each image with the mini c-arm were made by an institutional radiation physicist on the basis of testing of the emergency department x-ray machine and mini c-arm, as well as known standard power settings required to adequately image a forearm with use of either modality. Since both the study and control groups had initial radiographs made for evaluation of the injury, the radiation exposure for these radiographs was excluded from the radiation exposure calculation. Total radiation dose was calculated as the product of the average number of reduction radiographs in each group and the average radiation exposure from each image.
Statistical Analysis
The cohort and control groups were compared with use of the Student t test for continuous variables and chi-square test for categorical variables. A multinomial logistic regression was performed to determine the differences in fracture type between groups, after adjusting for sex and age. A p value of ≤0.05 was considered significant.
Source of Funding
No external funding was provided for this study.
Group Demographics (Table I)
A total of 279 forearm shaft fractures or distal radial and/or distal ulnar fractures satisfied the inclusion criteria. One hundred and thirteen patients were included in the mini-c-arm group and 166 in the radiograph or historical control group. Age and sex distributions were similar between groups. Fracture distributions were dissimilar, with the control group having significantly fewer distal radial and ulnar fractures and significantly more diaphyseal fractures of the forearm.
Quality of Reduction (Table II)
A complete set of prereduction and postreduction radiographs, along with appropriate three-month radiographs, were available for 152 patients in the control group and ninety patients in the mini-c-arm group. The average prereduction angulation and translation were similar for both groups. Although the average postreduction translation was not significantly different for either group, the average residual angulation was significantly lower in the mini-c-arm group (6° ± 4° vs. 8° ± 6°, p = 0.02).
Repeat Reductions and Additional Procedures (Table III)
In the control group, fourteen fractures (8.4%) required a second closed reduction after the initial reduction in the emergency department. Ten of the unsatisfactory initial reductions were repeated in the emergency department setting. Seven of these ten repeat reductions required the patient to be placed under sedation a second time, while the remaining three repeat reductions were performed without sedation, with use of intravenous analgesia and cast-wedging techniques. Three of the fourteen patients required a reduction in the operating room with fracture fixation. Of these three patients, two had an unsatisfactory second reduction with sedation in the emergency department. All three patients requiring operative fixation were boys between eleven and fourteen years of age. Two patients underwent closed reduction and pin fixation of a distal radial fracture, while one patient was treated with plate fixation for a radial and ulnar shaft fracture. One fracture was reduced in the office through a cast-wedging technique.
In the mini-c-arm group, only one fracture required a repeat reduction in the emergency department and one fracture needed operative intervention secondary to failure of closed treatment in the emergency department. Both were radial and ulnar shaft fractures. In all, only two patients (2%) in the mini-c-arm group required a second intervention and this was significantly fewer than the control group (p = 0.002). In addition, the one patient who required a repeat reduction did not require a second session of sedation.
Radiation Exposure (Table IV)
Complete documentation for the total number of images acquired for evaluation of a reduction was available for 152 patients in the control group and ninety patients in the mini-c-arm group. The number of individual images utilized to evaluate a fracture tended to be greater, on average, in the mini-c-arm group, and this result trended toward but did not reach significance when evaluated with reference to all patients or to fracture subgroup. Since the average radiation dose to the patient for each mini-c-arm image was substantially less than that of a radiograph, patients in the control group received an average of almost four times greater radiation than those in the mini-c-arm group (50.0 ± 12.7 mrem vs. 14.0 ± 10.3 mrem).
Even though the mini c-arm was used to evaluate all of the fracture reductions in the mini-c-arm group, two patients with displaced radial and ulnar shaft fractures required additional radiographs to assess the reduction. In both cases, the radial and ulnar fractures occurred at different levels such that the 6-in (15-cm) field of the mini c-arm was unable to assess both fractures simultaneously. Neither fracture required a repeat reduction.
Time Efficiency (Table V)
Documentation for time spent in the emergency department by the patient and by the orthopaedic resident varied according to the specific time interval examined. Overall, total patient time in the emergency department was not significantly different between the patients in the control group and those in the mini-c-arm group (mean, 252 ± 122 min vs. 271 ± 86; p = 0.10). However, total time spent by the orthopaedic resident was significantly less for the mini-c-arm group (mean, 47 ± 19 min vs. 28 ± 12 min; p < 0.001). Time from the beginning of the consultation to the discharge from the emergency department again did not differ significantly between groups (mean, 115 ± 85 min vs. 107 ± 52 min; p = 0.22).
The mini c-arm, or portable fluoroscopy, has many potential advantages over radiographs for the acute evaluation of a fracture reduction. First, the mini c-arm may allow an improvement in fracture reduction quality compared with standard radiographs. Mini-c-arm images are made as the reduction is occurring and therefore allow real-time adjustments to the fracture alignment during cast application. Postreduction radiographs are usually made a period of time after the reduction procedure and typically after the patient has awakened from sedation. The orthopaedist may be more inclined to accept an inferior reduction on radiographs in light of the potential risks of a repeat use of sedation and repeat closed reduction. Second, mini-c-arm fluoroscopy may offer a time savings for the orthopaedic consultation as a repeat postreduction radiograph is eliminated. Third, since the mini c-arm uses less radiation than radiographs, radiation exposure to the patient and staff is also potentially minimized.
Despite the theoretical advantages of the mini c-arm in treating pediatric forearm fractures, little to no clinical data exist to support any of the above claims. The current study is the first, as far as we know, to explore the clinical advantages of mini-c-arm use for pediatric forearm fractures in an emergency department setting. The first potential advantage is the improvement in fracture reduction quality. Overall, the mini-c-arm group had a significantly improved average residual angulation compared with the control group. Although the difference of 2° was significant, the result is of little direct clinical importance. A clear clinical advantage of improving reductions by 2° with use of a mini c-arm instead of radiographs is difficult to assert, given the broad range of acceptable angulations for pediatric forearm fractures. The result, instead, should be viewed as a summary of overall reduction quality in two comparable populations. A significant difference in postreduction angulation between historical control and mini-c-arm groups with normal distributions suggests that more patients in the control group will tend to have unacceptable reductions. This point is reinforced by the striking clinical data that the control group required repeat reductions or secondary procedures in fourteen patients, while the mini-c-arm group required such procedures in only two patients. The current data suggest that the so-called real-time evaluation of fracture reduction with the mini c-arm improves fracture reduction quality in the emergency department setting and can potentially minimize additional reduction procedures for the pediatric patient.
The time spent for an orthopaedic consultation, consisting of the initial reduction, cast application, and evaluation of postreduction radiographs, is of concern in a busy emergency department setting. The current data indicate that orthopaedic consultation time is decreased significantly by the use of a mini c-arm. However, total patient time in the emergency department was not decreased. The result implies that the evaluation and treatment by an orthopaedic surgeon, at least in the setting of our institution's emergency department, is not the rate-limiting factor for emergency department throughput. Unfortunately, the current study was not designed to identify specific inefficiencies in the emergency department, such as the time required for evaluation by an emergency department physician, the delay in obtaining the initial radiographs, and the potential delay in the arrival of the orthopaedic surgeon for consultation. Minimizing radiation exposure to the patient and staff in an emergency department setting is of paramount importance. The clinical data that are available for mini-c-arm radiation to the patient and practitioner are based on an operating-room environment or theoretical models2,7,8,12. Comparison of radiographs and mini-c-arm use for the evaluation of fracture reduction in the emergency department in this study suggests that patients are exposed to four times more radiation from radiographs than from mini-c-arm imaging to acquire the same information, despite the suggestion by the data that the mini c-arm may require more images, on average. The average mini-c-arm radiation for performance of a single reduction in the present study is 14.0 ± 10.3 mrem, which is less than that received from one chest radiograph (20 mrem) and far below the annual exposure limit of 300 mrem13.
Several limitations to the current study are noted. First, the study relies on information gathered from charts. The chart data for certain variables were at times incomplete and decreased the ability of the analysis to detect small differences between groups. A larger, prospective series may be able to better isolate differences that appeared to trend toward significance, such as the total patient time spent in the emergency department. In addition, it is challenging in a retrospective study to absolutely define a cause-and-effect relationship secondary to confounding variables that are both difficult to identify and to control. For example, the decreased time spent with the patient in the emergency department by the orthopaedic resident may not necessarily be a result of mini-c-arm use, but may have been produced by changes in training or have been peculiar to the specific resident group evaluating patients over the study interval. However, since there were no notable changes in emergency department practices, resident competencies, or national or local health-care delivery policies during the study period and no other obvious confounding factors were identified, the results in this study are thought to most likely result from the technological change of mini-c-arm use in the emergency department.
The distribution of fracture types between control and mini-c-arm groups was different. Ideally, demographic and fracture type characteristics between groups should be identical in order to offer a meaningful comparison. However, this difference does not appear to have influenced the most clinically important result, that of the increased number of repeat reductions and secondary procedures in the control group. The majority of fractures in the control group and the mini-c-arm group that required an additional procedure were derived from the relatively more rare fracture type for that age group, specifically distal radial fractures for the control group and fractures of both forearm bones for the mini-c-arm group. If fracture distribution significantly impacted the data on repeat reductions, then one would anticipate that the ratio of fracture types that required repeat procedures in either group would have mirrored the population ratio.
Further, no follow-up of greater than three months was available for the patients. Longer follow-up would have been desirable to determine whether patients required additional procedures for forearm malunion or nonunion. However, given the rarity of additional surgery for malunions or nonunions in our pediatric practice and most pediatric practices in general, one can theorize that longer-term follow-up would not have changed substantially the results of the study. In addition, the current study was designed to evaluate the immediate postreduction outcomes of patients who had a reduction with use of radiographs or a mini c-arm.
Finally, the radiation dose for the mini-c-arm group may have been underestimated since it was calculated from the number of images printed from the mini c-arm during fracture reduction. Residents using the mini c-arm were trained to print all preliminary reduction images and the final reduction images. The number of printed mini-c-arm images likely varied among residents, and no practical method existed to tabulate the number of actual fluoroscopic images used versus the number of printed images. However, despite the possible underestimation of mini-c-arm radiation, it is useful to consider that each patient would have had to be exposed to twenty mini-c-arm images, on average, in order to equal the radiation from the radiographs used for a similar evaluation. We believe that patients who need twenty mini-c-arm images are the exception and that the average number of images reported in this manuscript is consistent with our own clinical practice for closed reductions both in the emergency department and in the operating room.
In conclusion, the mini c-arm can improve the clinical outcome of pediatric forearm and distal radial and/or distal ulnar fractures undergoing closed treatment in the emergency department setting by improving the residual fracture alignment and decreasing the number of additional procedures required after the index closed reduction. The data also support the idea that the use of the mini c-arm to assist in the closed reduction of pediatric forearm fractures uses less radiation than standard radiographs. Further, the study demonstrates a clear time savings for the orthopaedic consultation when a mini c-arm is used for evaluation of fracture reductions as opposed to radiographs. A disadvantage to the use of the mini c-arm is its limited field of view, and its usefulness may therefore not be generalizable to all types of fractures. However, for fractures of the forearm and distal end of the upper extremity in pediatric patients, the current study demonstrates clear clinical advantages.
Note: The authors thank Dr. Zhu Wang for his statistical expertise.
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