Injuries  resulting from trauma remains a major global public health concern.[1,2] According to the World Health Organization, physical trauma is the leading cause of death among individuals under 45 years of age and contributes to nearly 10% of global mortality.[3] Musculoskeletal injuries constitute a substantial proportion of trauma-related morbidity and are frequently associated with long-term adverse effects on daily functioning, return to work, and health-related quality of life, thereby contributing significantly to the global burden of non-fatal injuries.[4,5]

Thoracic injuries account for approximately 10–15% of all trauma-related hospital admissions and represent the third most common category of injuries  among trauma patients.[6,7] The spectrum of thoracic trauma includes chest wall fractures, pulmonary injuries, and cardiovascular involvement. Thoracic injuries are broadly classified as blunt or penetrating injuries based on the mechanism of injury. Blunt chest trauma constitutes nearly 90% of thoracic injuries, most commonly resulting from motor vehicle collisions, whereas penetrating injuries account for the remaining 10%.[7] Rib fractures are the most frequent injuries  following blunt chest trauma and are identified in nearly 10% of polytrauma patients.[6,8-10] These fractures range from isolated, minimally displaced injuries to severe forms such as flail chest, which occurs when three or more consecutive ribs are fractured at two or more sites, resulting in paradoxical chest wall movement during respiration.[8]

Rib fractures are clinically significant due to their association with substantial pulmonary morbidity and mortality.[11,12] Even isolated rib fractures can lead to dyspnoea, persistent pain, and long-term functional impairment.[13,-15] Pain-related splinting of the chest wall compromises effective ventilation and coughing, predisposing patients to complications such as pneumothorax, pulmonary contusion, atelectasis, pneumonia, and respiratory failure requiring mechanical ventilation.[16,17] Physical examination and radiography remain the primary diagnostic tools for rib fractures; however, up to 51% of fractures may be missed using these methods alone, particularly those involving costal cartilage fractures.

AIMS AND OBJECTIVES

The aim of this study is to compare the diagnostic sensitivity of ultrasonography and radiography in the detection of rib fractures following blunt chest trauma. Specifically, the study seeks to evaluate the limitations of chest radiography, particularly in identifying fractures involving the costal cartilage, and to assess the effectiveness of ultrasonography in detecting rib fractures that may be overlooked on conventional chest X-ray in cases of minor blunt trauma. The study also aims to define the overall role of ultrasonography as a diagnostic tool in the evaluation of rib fractures.

Study Design This study was designed as a prospective observational study conducted over a period of two years, from June 2020 to June 2022. The research was carried out at a tertiary care centre, Meenakshi Medical College and Research Institute, Kanchipuram. The study population comprised of 50 patients presenting with a history of chest trauma who were evaluated for suspected rib fractures during the study period. Inclusion and Exclusion Criteria Patients with a history of blunt chest trauma presenting with aggravated chest pain on change in position, coughing, or deep inspiration, along with focal tenderness over the ribs, were included in the study. Patients were excluded if they had penetrating chest trauma, were haemodynamically unstable, were pregnant, or did not provide informed consent to participate in the study. Data Collection Procedure Patients with acute blunt chest trauma and clinically suspected rib fractures were included based on localized rib tenderness and chest pain aggravated by coughing or deep inspiration. Demographic details, clinical features, and injury-related information were collected using a structured questionnaire. All patients underwent ultrasonography using a 7.5 MHz linear transducer, performed by an emergency medicine resident, with the probe aligned along the long axis of the most painful rib; fractures were identified by cortical disruption, acoustic shadowing, or an associated hematoma. Subsequently, posteroanterior chest radiographs with oblique rib views were obtained and interpreted by a blinded senior resident. The duration of both imaging procedures was recorded. In the absence of a definitive gold standard, rib fractures detected by either modality were considered confirmatory evidence. Variables analyzed included age, gender, BMI, clinical presentation, mechanism of injury, complications, and the number of patients and ribs diagnosed as fractured by ultrasonography and radiography. Statistical Analysis The collected data were entered into Microsoft Excel and analyzed using SPSS version 22. Descriptive statistics were expressed as proportions or as means with standard deviation. Sensitivity analysis was performed using appropriate diagnostic test formulas. The paired t-test was applied to compare the time taken for ultrasonography and radiographic investigations. A p-value of less than 0.05 was considered statistically significant.

Table 1 shows that the study population had a mean age of 41.3 years with a male predominance (62%). The average BMI was 27.1 kg/m², and nearly one-fourth of participants were obese, indicating a moderate prevalence of overweight status among patients with blunt chest trauma.

Table 2 observes that falls were the most common mechanism of injury, accounting for more than half of the cases, followed by road traffic accidents and direct blunt impact to the chest.

Table 3 demonstrates that all patients presented with pain aggravated by coughing and inspiration. Focal tenderness and bruising were also common, reinforcing their diagnostic value in suspected rib fractures.

Table 4 shows that the anterior chest wall was the most frequent site of pain, followed by posterior chest wall and hemithorax involvement, indicating varied rib involvement patterns.

Table 5 illustrates that cortical disruption was the most common ultrasonographic sign of rib fracture, while nearly one-fourth of cases also demonstrated associated hematoma.

Table 6 shows that ultrasonography detected a significantly higher number of rib fractures compared to radiography. When both modalities were combined, all fractures were identified, indicating complementary diagnostic value.

Table 7 demonstrates that ultrasonography not only showed higher sensitivity compared to radiography but also required significantly less time to perform, making it a faster and more efficient diagnostic modality in emergency settings.

This prospective study evaluated the diagnostic performance of ultrasonography (USG) and conventional radiography in the detection of rib fractures among patients presenting with blunt chest trauma. A total of 50 patients were included, all of whom underwent both imaging modalities. The mean age of participants was 41.3±15.3 years, with a male predominance (62%), findings which are consistent with the demographic profile reported in previous trauma-based studies.[18] The mean body mass index was 27.1 kg/m², and obesity was present in 22% of patients, a factor that  has been previously identified as a potential limiting factor for ultrasonographic visualization.

Falls were the most common mechanism of injury (54%), followed by road traffic accidents and direct blunt trauma, a distribution comparable to that reported by Pishbin et al.[19] Clinically, all patients presented with pain aggravated by coughing and deep inspiration, while focal tenderness and bruising were observed in 93% and 86% of cases, respectively. The anterior chest wall was the most frequent site of pain, followed by the posterior chest wall and hemithorax involvement, mirroring patterns observed in earlier studies.[19]

Ultrasonography demonstrated superior diagnostic performance compared to radiography in both patient-based and rib-based analyses. USG detected 42 out of 44 fractured ribs (95.4%) in 33 patients (96.07%), whereas radiography detected 34 ribs (77.2%) in 27 patients (79.4%). These findings support previous literature demonstrating the higher sensitivity of USG for rib fracture detection, particularly for nondisplaced and costochondral fractures that may be missed on radiographs.[18-22] The use of both posteroanterior and oblique rib views likely contributed to the relatively higher sensitivity of radiography in this study compared with some earlier reports.[21]

The specificity of both modalities was 100%, and the negative predictive value of USG was notably higher than that of radiography. However, the kappa agreement between USG and radiography was only moderate (0.628), indicating that radiography alone may miss a substantial proportion of fractures detected by ultrasonography. Similar discrepancies have been reported in prior comparative studies.[18-21]

Associated complications included pleural effusion, pneumothorax, and clavicle fractures, emphasizing the importance of early fracture detection. USG also required significantly less time than radiography (13.7 vs. 25.8 minutes; p = 0.001), supporting its utility as a rapid bedside diagnostic tool, especially in emergency settings and haemodynamically unstable patients.[18]

Despite its advantages, ultrasonography missed two posterior rib fractures located beneath the scapula, highlighting a known limitation of the modality. Additionally, obesity and increased chest wall thickness may reduce image quality, as reported previously.[19]

The findings of this study reinforce existing evidence that ultrasonography is a more sensitive and time-efficient modality than conventional radiography for the diagnosis of rib fractures following blunt chest trauma, while acknowledging its operator dependence and anatomical limitations.

Limitations

The principal limitation of this study is that the experience and skill level of the investigator performing ultrasonography, which can significantly influence diagnostic accuracy, were not evaluated. As ultrasonography is an operator-dependent modality, this factor may have affected the results. However, the prospective study design and the use of standardized equipment and uniform imaging protocols across all participants strengthen the validity and reliability of the study findings.

Ultrasonography is more sensitive than conventional radiography for diagnosing rib fractures in patients with blunt chest trauma in the emergency department. It allows rapid, radiation-free detection of fractures that may be missed on X-ray; however, its effectiveness is limited in visualizing upper rib fractures hidden by the scapula and in obese patients. Despite these limitations, ultrasonography remains a valuable initial diagnostic tool.

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