Assessing the Pelvic X-ray Findings of High-energy Multiple Trauma Patients in Emergency Department of Rajaee Trauma Hospital, Shiraz-October 2013 to May 2014

Background: Because of the significance of pelvic fracture, anteroposterior pelvic X-ray (PXR) is routinely performed for all patients referring to the emergency department with multiple trauma. But routine performance of PXR may have several complications


Introduction
Trauma is a leading cause of mortality and morbidity, especially in developing countries, such as Iran. The pelvis is commonly injured due to the high impact of blunt trauma such as motor vehicle accident or a pedestrian being hit by a car. Pelvic fracture present approximately 3% of selected injuries [1], overall mortality ranges from 5-16% with the rate for unstable pelvic fracture of 8% [2]. Hemorrhage is the leading cause of death in patients with pelvic fracture [3]. Thus, early and proper diagnosis and management are necessary for patients' survival.
Several radiographies, like cervical spine and thoracolumbar radiography [4,5] have been suggested for blunt high-energy traumatic patients. Pelvic fracture, on the other hand, is a life-threatening issue in patients with multiple trauma, because of masked massive hemorrhage [6]. The predictive value of pelvic physical examination has been reported to be different in various studies [7][8][9]. Thus, Advanced Trauma Life Support (ATLS) has suggested anteroposterior Pelvic X-Ray (PXR) for all patients referring to the emergency department with multiple trauma [10]. This importance is emphasized by ATLS as adjuvant to primary survey. The reason for ATLS's emphasis on pelvic x-ray is the knowledge of pelvic fracture and is not often based solely on clinical findings, it is possible by pelvic X-ray. Knowing the pelvic fracture makes a lot of change in patient's management. Since then, all physicians follow this algorithm as a routine, as it is also an additional predictor of injury severity and 24-hour blood requirement [11] and has been strongly suggested for hemodynamically unstable or unconscious patients [12][13][14].
Yet, radiography has a high radiation rate [15] and avoiding routine PXR, especially in awake patients with no pain and normal physical examination reduces its costs and complications [9,16,17]. Conversely, studies have reported low sensitivity of PXR as low as 60% [3,7,[17][18][19], although its low diagnostic value might be improved by training emergency department physicians [20], some have suggested other imaging methods, such as CT scan and MRI [21], in severely injured multiple trauma patients [22], but it also have a high radiation dose, higher cost, and complications, especially as most traumatic patients are young individuals [23] and they need special devices that may not be available in all centers, especially in developing countries, like Iran. Regarding several controversies about PXR in traumatic patients, this study aimed to assess the PXR findings in traumatic patients referring to emer-gency department of Rajaee Trauma hospital, a level 1 crowded emergency department in Shiraz, Iran.

Materials and Methods
In this prospective study, Four-hundred traumatic patients were recruited for the study referring to level 1 triage center of Rajaee Trauma Hospital, Shiraz, Iran, with the population of 2 million from October 2013 to May 2013 were recruited. The research protocol was approved by the Ethics Committee of the center. Recruiting patients into the study was based on convenient sampling. Informed written consent for participation in research was obtained from all patients. Demographic data, including age, gender, type of accident, and type of hip fracture was recorded in a checklist. A detailed history was taken from all patients and meticulous physical examination was performed for all of them by the emergency medicine specialist. PXR was performed for selected patients according to Rajaee Hospital's guideline, including decreased level of consciousness (GCS<13) ; hip pain; tenderness on compression of the iliac wings, on bilateral inversion and eversion of the anterior superior iliac spine, or in hip flexion, internal or external rotation of the hip ; pubic symphysis tenderness; confounding pain in the posterior midline of the lumbar spine (indicator of the possibility of fracture); presence of limb length inequalities; unrevealing or unreliable pelvic physical examination for any reason [24]. All images were reported accurately by a unique radiologist.

Statistical Analysis
Categorical variables were described by numbers and percentages, whereas mean ± standard deviation was used to describe continuous variables. Data were analyzed using Chi-square or Fisher's exact test to assess the relationships between categorical variables and statistical analysis was performed using SPSS 18.0 software. P-value less than 0.05 was considered significant.

Results
During the study period, considering the inclusion/exclusion criteria, 402 patients referred to the level 1 triage center of Rajaee trauma hospital with high-energy blunt trauma and the data of 400 cases were analyzed, as two patients did not give consent to participate in the study. Data showed that the mean age of patients was 36.1±17.5 (range: 14-90), with 81.5% under 50 years. The majority of patients, 320 (80%), were also male. The most frequent causes of injury included 55.6% motor vehicle accidents with the highest frequency in car turnover and car-to-pedestrian accidents (both 17%) (  Chi-square test also revealed a significant association between patients' gender and some types of accidents: Motor-to-car and car-to-pedestrian accidents were significantly higher in female patients (P=0.02 and 0.001) and car-to-car accidents were significantly higher in male patients (P=0.004) ( Table 1).
The most frequent pelvic fractures were left superior and inferior pubic ramus (12.8 and 12.5%) followed by right inferior pubic ramus fracture (10.5%) (

Discussion
Trauma is a major cause of morbidity and mortality and paying attention to different aspects of trauma care is an important health matter, as pelvic fracture causes fatal internal bleeding and the majority of affected patients are male young patients. Therefore, the choice of imaging method is very important for early diagnosis with minor adverse effects and complications.
Al Balushi et al.,[25] compared the incidence of pelvic fracture diagnosed by pelvic X-ray and computed tomography to evaluate the need of pelvic X-ray in the management of haemodynamically stable polytrauma patients and found that computed tomography is a superior in detecting pelvic femoral and lumbar fractures. Study of Gordic et al.,[26] determined the number of imaging examinations in multiple trauma patients and showed that CT examinations are needed.
In our study, we performed PXR selectively for the traumatic patients with the indicated inclusion criteria according to Rajaee Hospital's guideline and have concluded that precise history taking and physical examination is very important to select patients who require PXR in emergency room. Although some studies suggest performing PXR routinely for all traumatic patients [11], it will expose them to unnecessary radiation and as far as the patients usually suffer from multiple trauma, they mostly require a series of radiographies for neck, chest, and other imaging. Besides, the traumatic patients are mostly young and it is thus unethical to expose a young patient to unnecessary radiation that disposes them to cancer and other important complications of over-radiation. Moreover, it is not cost effective to perform PXR for all traumatic patients entering the emergency. Therefore, it is optimal to perform PXR in selective patients.
The results of the present study showed that the mentioned criteria for selecting patients for PXR, which was similar to other studies. A recent study conducted by Paydar et al. [25] prospectively evaluated 1002 blunt trauma Iranian patients and have concluded sufficiency of radiographic imaging in stable patients with normal physical examination that will reduce the excessive cost and radiation. Duane and colleagues have compared the radiologic findings of 520 traumatic patients with positive physical examination with 1441 controls and have reported that all pelvic fractures were identified by history and physical examination and suggested that elimination of PXR in awake and alert patients saves a large amount of costs and have proposed the protocol that PXR should only be performed in severely injured patients [17]. Yugueros and colleagues have also assessed 608 hemodynamic stable patients and found that 9.7% of patients had pelvic fractures and have proposed cost-effectiveness of the selective use of PXR [16]. Gonzales et al.,[27] have reported 4.5% pelvic fractures in blunt trauma patients and have reported 87% sensitivity for PXR. They have clearly concluded that routine PXR will not increase its diagnostic sensitivity and have suggested PXR in patients with positive physical examination as a reliable diagnostic tool to rule out pelvic fractures. The protocol for selective PXR in the above-mentioned studies were all similar to the protocol of the current study (pelvic pain, pelvic girdletenderness, pelvic deformities, limb inequalities and signs of bleeding in rectal examination) and the results obtained were also similar to ours. Besides, the higher rate presented in the current study reflects the fact that we have only performed PXR selectively for patients with the above-mentioned criteria.
Other studies have reported necessity and indication of PXR in comparison to CT imaging. Paydar study [28] retrospectively investigated routine performance of PXR in 1679 high-energy blunt trauma Iranian patients with negative pelvic physical examination and have concluded that elimination of PXR in awake and hemodynamically stable patients would not change the therapeutic approach and will save healthcare resources. They have also questioned the necessity of CT scan in such patients, especially due to its high cost and radiation, its unavailability in all centers, and long duration of imaging time. Hilty et al.,[18] also suggested that routine PXR can safely be removed in hemodynamically stable patients, although they have reported low predictive value of PXR, compared to CT scan. Guillamondegui et al.,[29] have suggested limitation of PXR to unstable patients. The above-mentioned studies also confirms that PXR can be safely performed for selective patients, as performed in the protocol of our study.
Some other studies have compared the false negative rates for PXR compared to other imaging methods, such as CT scan and MRI [12,18,29,30]. Also they have reported that around 10-30% of fractures are not defined by plain radiography, some other researchers have declared that CT scan would not change the management [31] and have thus reported PXR sufficient. Moreover, using CT scan and MRI is not practical in emergency cases, especially in developing countries, where the devices are not available everywhere and imposes a higher cost to the patients and health system.
The strengthening point of our study was assessing all causes of injury and fractures in patients, which has been scarcely studied in Iran. We also tried to exclude confounding factors in our assessment, to be able to evaluate the PXR findings in multiple trauma patients. Yet, the study would have been more thorough, when we considered other socio-economic, psychologic, and other demographic details of the patients and compare the results of radiographies with CT scans. We also did not have the choice to follow the patients, to observe if they required repeating the imaging or what further interventions they needed. Future studies are needed to give the emergency medicine specialists a better view in diagnosis and management of multiple traumatic patients.

Conclusion
The results of the current study, in accordance to previous studies, suggest that PXR is an appropriate diagnostic tool for pelvic fractures and is most proper to be selectively performed in patients with the criteria mentioned in the current study and more attention should be paid to superior and inferior pubic ramus fractures, as it was found to be the most frequent fractures observed in the present study.