American Journal of Emergency Medicine 32 (2014) 171–174
Contents lists available at ScienceDirect
American Journal of Emergency Medicine journal homepage: www.elsevier.com/locate/ajem
Brief Report
The accuracy of bedside ultrasonography as a diagnostic tool for the fifth metatarsal fractures Murat Yesilaras, MD a,⁎, Ersin Aksay, MD a, Ozge Duman Atilla, MD a, Mustafa Sever, MD a, Onder Kalenderer, MD b a b
Department of Emergency Medicine, Izmir Tepecik Research and Educational Hospital, Izmir, Turkey Department of Orthopedics and Traumatology, Izmir Tepecik Research and Educational Hospital, Izmir, Turkey
a r t i c l e
i n f o
Article history: Received 29 July 2013 Received in revised form 1 November 2013 Accepted 5 November 2013
a b s t r a c t Objectives: Musculoskeletal ultrasonography is a technique that is becoming more popular in diagnosing injuries of emergency department (ED) patients especially for the diagnosis of fractures. In this study, we determined the reliability of ultrasonography for the diagnosis of fractures of the fifth metatarsal. Method: This is a prospective blind study. Patients over 14 years old who were admitted to the ED with acute foot injury and who had tenderness on the fifth metatarsal were consecutively enrolled into the study. A bedside ultrasonography exam was performed by an emergency physician, and antero-posterior and oblique views were obtained. X-rays were blindly evaluated by an orthopedic surgeon and were considered to be the gold-standard for diagnosing fractures. In patients with noncomminuted fractures, bone displacement was measured by both radiologically and sonographically. Results: Eighty-four patients were included in this study. Their mean age was 36.0, and 42.9% were male. Fractures were diagnosed by both x-ray and ultrasonography in 33 patients. In one patient, the x-ray was positive for fracture, while ultrasonography yielded a negative result. For the fractures of fifth metatarsal, the diagnostic sensitivity of ultrasonography was 97.1%, the specificity was 100%, the positive likelihood ratio was infinity, the negative likelihood ratio was 0.03. Mean displacement was 1.2 ± 0.7 mm with x-ray and 1.8 ± 1.5 mm with ultrasonography. The intraclass correlation coefficient of displacement measured by x-ray and ultrasonography was κ: 0.388. Conclusion: Ultrasonography is a reliable diagnostic tool for acute fifth metatarsal fractures. © 2013 Elsevier Inc. All rights reserved.
1. Introduction The popularity of musculoskeletal ultrasonography (US) has increased and is now commonly used by clinicians. US technology is often referred to as “the orthopedic stethoscope” and has many advantages, including no exposure to radiation, wide availability, cost-effectiveness, and the ability to be used at the bedside [1]. US can distinguish fractures by cortical disruption [2,3]. Recently, there have been a number of studies regarding the diagnosis of fractures with US [4,5]. Five percent of the fractures seen in the emergency department (ED) are metatarsal fractures, and more than half of these include fractures of the fifth metatarsal [6]. x-Ray is the most commonly used diagnostic study for fractures. Although there are publications that demonstrate that x-ray is not reliable in the diagnosis of fractures in patients with a hyperflexion injury of the foot, it is widely accepted that x-ray can be used in the diagnosis of fifth metatarsal fractures [7,8]. In comparison, magnetic resonance
⁎ Corresponding author. Tel.: +90 232 4696969. E-mail address: [email protected] (M. Yesilaras). 0735-6757/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajem.2013.11.009
imaging (MRI) and scintigraphy are suggested to be used only in diagnosis of stress fractures. In most of the studies on adult and pediatric patients with traumatic fractures, the diagnosis of the fracture is done by cortical disruption [9-12]. x-Ray results are negative when obtained early in stress fractures, and the cortical distribution cannot be observed in US. In a previous study, the diagnosis of stress fracture by US examining hypoechoic periosteal elevation or increased vascularity on Color Doppler [13]. Based on a comprehensive literature search, we found that there are no reports on the reliability of US for the diagnosis of acute traumatic metatarsal fractures. We aimed to determine the diagnostic accuracy of US on patients who were admitted to the ED with foot injury and tenderness on the fifth metatarsal. 2. Methods This prospective blind study was held between November 2011 and March 2013 in a tertiary urban ED with an annual admission rate of nearly 200,000. Ethical approval was obtained prior to the study from the local ethics committee, and patient consent was obtained to participate in the study.
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M. Yesilaras et al. / American Journal of Emergency Medicine 32 (2014) 171–174
Patients over 14 years old who were admitted to the ED with an acute foot injury and tenderness in their fifth metatarsal were consecutively included in the study. Patients were excluded from the study if they did not want to participate in the study, if they had open wounds on the fifth metatarsal, if there was no available x-ray, if there was a loss of sonographer blindness, or if there was no sonographer available upon admission to the ED. The US was performed by an experienced attending emergency physician with the emergency application of US. The sonographer did not have any special training in musculoskeletal US. The sonographer began examining patients for this study after performing US on 5 test patients with a fracture on the fifth metatarsal. First, the patients were examined by bedside US, followed by anteroposterior and an oblique foot X-ray. USs were performed with a 7.5 to 10 MHz linear probe (Mindray M5, color Diagnostic Ultrasound System, China). The fifth metatarsals were visualized from the longitudinal and transverse planes, and from both the dorsal and lateral aspects. Diagnosis of fracture by US is done only by cortical disruption (Figs. 1 and 2). Demographic data, the mechanism and time of the injury, and application time were recorded. An orthopedic surgeon who was blinded to the results of the US evaluated the x-ray from the Picture Archiving and Communication System (PACS). The evaluation of the orthopedic surgeon was considered to be the gold-standard for the diagnosis. In patients with non-comminuted fractures, the bone displacement was measured by both x-ray and US. The measurements were taken from the widest part of the displacements.
2.1. Analysis Statistical analyses were performed using SPSS 16.0.1 software (SPSS Inc., Chicago, IL). Qualitative data were given as frequency and percentage, while quantitative data were given as median, mean, standard deviation, and minimum/maximum values. The likelihood ratio of a positive test (LR +), the likelihood ratio of a negative test (LR −), the negative predictive value, the positive predictive value, sensitivity, and specificity were calculated using a 2 × 2 table with 95%
confidence intervals. Interclass coefficient was used to compare the fracture displacement measurements taken with x-ray and US. 3. Results Eighty-nine patients that matched the inclusion criteria were admitted to ED during the study period. Four patients were excluded from the study due to loss of sonographer blindness. US was performed on the remaining 85 patients. One patient’s x-ray was not available on PACS, and this patient was also excluded from the study. Therefore, the study was completed with 84 patients. Thirty-six of the patients were male (42.9%), and the mean age was 36.0 ± 15.0 years (min 14, max 72). The mean time between the injury and admission to the hospital was 11.9 ± 21.3 hours (min 0.5, max 120). Of the injuries, 89.3% resulted from foot inversion, and 10.7% arose from direct trauma to the foot. The median US application time was recorded as 4 minutes (min 2, max 6). Fracture was diagnosed by both US and x-ray in 33 patients. In one patient, US was normal, but an x-ray revealed a nondisplaced avulsion fracture on proximal of the fifth metatarsal. The fracture prevalence was 40.5% (34 patients). Sixteen of the cases had an avulsion fracture (47.1%), 12 cases had a Jones fracture (35.3%), 3 cases had a shaft fracture (8.8%), 2 cases had a distal head fracture (5.9%), and 1 case had a proximal diaphyseal fracture (2.9%). The diagnostic sensitivity of US for the fifth metatarsal fractures was 97.1% (95% CI, 82.9%99.8%), and its specificity was 100% (95% CI, 91.1%-100%). The positive likelihood ratio was infinity, and the negative likelihood ratio was 0.03 (95% CI, 0.01 to 0.21). The positive predictive values and negative predictive values were 100% (95% CI, 97%-100%) and 98% (95% CI, 88.2%-99.9%), respectively. The patients' x-ray and US results are presented in Figs. 1 and 2. In 26 patients who had non-comminuted fractures, the mean displacement was 1.2 ± 0.7 mm (min 0.3, max 2.9) by x-ray and 1.8 ± 1.5 mm (min 0.2, max 5.5) by US. There was a fair agreement between the fracture displacement measured by US and x-ray. (κ: 0.;88, 95% CI, 0.022-0.664). The fifth metatarsal distal epiphysis was detected by x-ray and US in only one (14 years old) of 14 patients who were under 21 year old. There was tenderness in the proximal fifth metatarsal of the patient. Injury was diagnosed as an avulsion fracture by both US and x-ray. 4. Discussion
Fig. 1. A 60-year-old male was admitted to the ED with an ankle sprain. (A) Jones fracture was obvious on the x-ray. (B) The cortical disruptions were identified on the proximal fifth metatarsal (arrow).
In the last 15 years, the application of US for the diagnosis of extremity fractures has grown widely [14,15]. However, to our knowledge, there has been no study reporting the reliability of US for the diagnosis of fifth metatarsal fractures. We found that bedside US performed by the emergency physician has a high sensitivity and specificity for the diagnosis of metatarsal fractures. A recent meta-analysis determined the diagnostic accuracy of bedside US for extremity fractures. [16] Eight studies were evaluated (including injuries to the clavicle and upper and lower extremity fractures in a pediatric population, as well as injuries to the femur, humerus, and hand fractures in adults) in this meta-analysis. The sonographers were not trained in musculoskeletal US for these studies. Patients with open fractures, evident deformities, and neurovascular injury were excluded. The overall sensitivity of US in extremity fractures ranged between 83.3% and 100%, and its specificity ranged between 73% and 100%. The positive LR ranged between 3.2 and 56, while the negative LR ranged between and 0.0 to 0.2. Banal et al studied the accuracy of US for the diagnosis of fifth metatarsal stress fractures in patients who had a normal X-ray [13]. US was performed by an experienced rheumatologist, and MRI was accepted as the gold-standard for stress fracture. “Hypoechoic periosteal elevation,” “cortical disruption,” and “increased vascularity
M. Yesilaras et al. / American Journal of Emergency Medicine 32 (2014) 171–174
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Fig. 2. A 28-year-old female with a fifth metatarsal avulsion fracture. (A and B) Subtle fracture was seen on the x-ray. (C) The small cortical gaps were identified on the fifth metatarsal (arrow).
around the periosteal lesion on power Doppler” were considered as evidence for fracture diagnosis. In this study, the sensitivity of bedside US of the fifth metatarsal fractures was 83%, the specificity was 76%, the positive predictive value was 59%, the negative predictive value was 92%, the positive LR was 3.45, and the negative LR was 0.22. These data support that US may be used as a reliable diagnostic tool for patients who have a high suspicion of fifth metatarsal stress fractures, even if their x-rays are normal. In our study, the sensitivity and specificity of US for the diagnosis of fractures determined by X-ray were 97.1% and 100%, respectively. Because of its excellent sensitivity and specificity, US should be considered an alternative diagnostic tool for the detection of fifth metatarsal fracture. The fifth metatarsal is suitable for ultrasonographic examination because of its superficial location and smooth cortex. The bone can be easily visualized from multiple planes. Lack of the sesamoid bone and ephyphysial line in the area being examined also contribute to the high accuracy of US. There were no false positive US results. There was only one false-negative patient who had non displacement avulsion fracture on the proximal metatarsal. This patient was discharged from the ED with a short leg splint. Chen et al studied the application of US in monitoring the closed reduction of distal radius fractures [17]. The volar, dorsal, and radial displacements were measured by both x-ray and US and were compared before and after reduction. All of the measured displacements were similar, and there were no significant differences between US and X-ray. In our study, the agreement of displacements measured by X-ray and US was fair. We believe that the measurements performed with US are more accurate than those taken by x-ray since US has the ability to measure the widest gap between the fracture fragments from multiple planes. 4.1. Limitation One limitation of this study is that only one sonographer performed all of the US. For the diagnosis of a fracture, x-ray was used as the gold-standard. We may have overlooked some patients
with occult fractures because of the lower sensitivity of x-ray for metatarsal fractures as compared to computed tomography and MRI [7]. In further prospective studies, MRI or scintigraphy should be used as the gold standard. 5. Conclusion In patients admitted to the ED with foot trauma, bedside US can be used as an appropriate diagnostic tool for fifth metatarsal fractures. References [1] Blankstein A. Ultrasound in the diagnosis of clinical orthopedics: the orthopedic stethoscope. World J Orthop 2011;2(2):13–24. [2] Chan SS. Emergency bedside ultrasound for the diagnosis of rib fractures. Am J Emerg Med 2009;27(5):617–20. [3] Beltrame V, Stramare R, Rebellato N, et al. Sonographic evaluation of bone fractures: a reliable alternative in clinical practice? Clin Imaging 2012;36(3): 203–8. [4] Ang SH, Lee SW, Lam KY. Ultrasound-guided reduction of distal radius fractures. Am J Emerg Med 2010;28(9):1002–8. [5] Yıldırım A, Unlüer EE, Vandenberk N, Karagöz A. The role of bedside ultrasonography for occult scaphoid fractures in the emergency department. Ulus Travma Acil Cerrahi Derg 2013;19(3):241–5. [6] Banerjee R, Florian Nickisch F, et al. Foot Injuries. In: Browner BD, Levine AM, Jupiter JB, et al, editors. Skeletal Trauma: Basic Science, Management, and Reconstruction, 4e. Philadelphia, PA: Saunders Elsevier; 2009. p. 2584–747. [7] Preidler KW, Peicha G, Lajtai G, et al. Conventional radiography, CT, and MR imaging in patients with hyperflexion injuries of the foot: diagnostic accuracy in the detection of bony and ligamentous changes. AJR Am J Roentgenol 1999;173(6):1673–7. [8] Hatch RL, Alsobrook JA, Clugston JR. Diagnosis and management of metatarsal fractures. Am Fam Physician 2007;76(6):817–26. [9] Fusetti C, Poletti PA, Pradel PH, et al. Diagnosis of occult scaphoid fracture with high spatial resolution sonography: a prospective blind study. J Trauma 2005;59(3):67781. [10] Marshburn TH, Legome E, Sargsyan A, et al. Goal-directed ultrasound in the detection of long-bone fractures. J Trauma 2004;57(2):329–32. [11] Tayal VS, Antoniazzi J, Pariyadath M, Norton HJ. Prospective use of ultrasound imaging to detect bony hand injuries in adults. J Ultrasound Med 2007;26(9): 1143–8. [12] Patel DD, Blumberg SM, Crain EF. The utility of bedside ultrasonography in identifying fractures and guiding fracture reduction in children. Pediatr Emerg Care 2009;25(4):221–5.
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[13] Banal F, Gandjbakhch F, Foltz V. Sensitivity and specificity of ultrasonography in early diagnosis of metatarsal bone stress fractures: a pilot study of 37 patients. J Rheumatol 2009;36(8):1715–9. [14] Rabiner JE, Khine H, Avner JR, et al. Accuracy of point-of-care ultrasonography for diagnosis of elbow fractures in children. Ann Emerg Med 2013;61(1):9–17. [15] Patil P, Dasgupta B. Role of diagnostic ultrasound in the assessment of musculoskeletal diseases. Ther Adv Musculoskelet Dis 2012;4(5):341–55.
[16] Joshi N, Lira A, Mehta N, et al. Diagnostic accuracy of history, physical examination, and bedside ultrasound for diagnosis of extremity fractures in the emergency department: a systematic review. Acad Emerg Med 2013;20(1): 1–15. [17] Chern TC, Jou IM, Lai KA. Sonography for monitoring closed reduction of displaced extra-articular distal radial fractures. J Bone Joint Surg Am 2002;84A(2):194–203.
Contents lists available at ScienceDirect
American Journal of Emergency Medicine journal homepage: www.elsevier.com/locate/ajem
Brief Report
The accuracy of bedside ultrasonography as a diagnostic tool for the fifth metatarsal fractures Murat Yesilaras, MD a,⁎, Ersin Aksay, MD a, Ozge Duman Atilla, MD a, Mustafa Sever, MD a, Onder Kalenderer, MD b a b
Department of Emergency Medicine, Izmir Tepecik Research and Educational Hospital, Izmir, Turkey Department of Orthopedics and Traumatology, Izmir Tepecik Research and Educational Hospital, Izmir, Turkey
a r t i c l e
i n f o
Article history: Received 29 July 2013 Received in revised form 1 November 2013 Accepted 5 November 2013
a b s t r a c t Objectives: Musculoskeletal ultrasonography is a technique that is becoming more popular in diagnosing injuries of emergency department (ED) patients especially for the diagnosis of fractures. In this study, we determined the reliability of ultrasonography for the diagnosis of fractures of the fifth metatarsal. Method: This is a prospective blind study. Patients over 14 years old who were admitted to the ED with acute foot injury and who had tenderness on the fifth metatarsal were consecutively enrolled into the study. A bedside ultrasonography exam was performed by an emergency physician, and antero-posterior and oblique views were obtained. X-rays were blindly evaluated by an orthopedic surgeon and were considered to be the gold-standard for diagnosing fractures. In patients with noncomminuted fractures, bone displacement was measured by both radiologically and sonographically. Results: Eighty-four patients were included in this study. Their mean age was 36.0, and 42.9% were male. Fractures were diagnosed by both x-ray and ultrasonography in 33 patients. In one patient, the x-ray was positive for fracture, while ultrasonography yielded a negative result. For the fractures of fifth metatarsal, the diagnostic sensitivity of ultrasonography was 97.1%, the specificity was 100%, the positive likelihood ratio was infinity, the negative likelihood ratio was 0.03. Mean displacement was 1.2 ± 0.7 mm with x-ray and 1.8 ± 1.5 mm with ultrasonography. The intraclass correlation coefficient of displacement measured by x-ray and ultrasonography was κ: 0.388. Conclusion: Ultrasonography is a reliable diagnostic tool for acute fifth metatarsal fractures. © 2013 Elsevier Inc. All rights reserved.
1. Introduction The popularity of musculoskeletal ultrasonography (US) has increased and is now commonly used by clinicians. US technology is often referred to as “the orthopedic stethoscope” and has many advantages, including no exposure to radiation, wide availability, cost-effectiveness, and the ability to be used at the bedside [1]. US can distinguish fractures by cortical disruption [2,3]. Recently, there have been a number of studies regarding the diagnosis of fractures with US [4,5]. Five percent of the fractures seen in the emergency department (ED) are metatarsal fractures, and more than half of these include fractures of the fifth metatarsal [6]. x-Ray is the most commonly used diagnostic study for fractures. Although there are publications that demonstrate that x-ray is not reliable in the diagnosis of fractures in patients with a hyperflexion injury of the foot, it is widely accepted that x-ray can be used in the diagnosis of fifth metatarsal fractures [7,8]. In comparison, magnetic resonance
⁎ Corresponding author. Tel.: +90 232 4696969. E-mail address: [email protected] (M. Yesilaras). 0735-6757/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajem.2013.11.009
imaging (MRI) and scintigraphy are suggested to be used only in diagnosis of stress fractures. In most of the studies on adult and pediatric patients with traumatic fractures, the diagnosis of the fracture is done by cortical disruption [9-12]. x-Ray results are negative when obtained early in stress fractures, and the cortical distribution cannot be observed in US. In a previous study, the diagnosis of stress fracture by US examining hypoechoic periosteal elevation or increased vascularity on Color Doppler [13]. Based on a comprehensive literature search, we found that there are no reports on the reliability of US for the diagnosis of acute traumatic metatarsal fractures. We aimed to determine the diagnostic accuracy of US on patients who were admitted to the ED with foot injury and tenderness on the fifth metatarsal. 2. Methods This prospective blind study was held between November 2011 and March 2013 in a tertiary urban ED with an annual admission rate of nearly 200,000. Ethical approval was obtained prior to the study from the local ethics committee, and patient consent was obtained to participate in the study.
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M. Yesilaras et al. / American Journal of Emergency Medicine 32 (2014) 171–174
Patients over 14 years old who were admitted to the ED with an acute foot injury and tenderness in their fifth metatarsal were consecutively included in the study. Patients were excluded from the study if they did not want to participate in the study, if they had open wounds on the fifth metatarsal, if there was no available x-ray, if there was a loss of sonographer blindness, or if there was no sonographer available upon admission to the ED. The US was performed by an experienced attending emergency physician with the emergency application of US. The sonographer did not have any special training in musculoskeletal US. The sonographer began examining patients for this study after performing US on 5 test patients with a fracture on the fifth metatarsal. First, the patients were examined by bedside US, followed by anteroposterior and an oblique foot X-ray. USs were performed with a 7.5 to 10 MHz linear probe (Mindray M5, color Diagnostic Ultrasound System, China). The fifth metatarsals were visualized from the longitudinal and transverse planes, and from both the dorsal and lateral aspects. Diagnosis of fracture by US is done only by cortical disruption (Figs. 1 and 2). Demographic data, the mechanism and time of the injury, and application time were recorded. An orthopedic surgeon who was blinded to the results of the US evaluated the x-ray from the Picture Archiving and Communication System (PACS). The evaluation of the orthopedic surgeon was considered to be the gold-standard for the diagnosis. In patients with non-comminuted fractures, the bone displacement was measured by both x-ray and US. The measurements were taken from the widest part of the displacements.
2.1. Analysis Statistical analyses were performed using SPSS 16.0.1 software (SPSS Inc., Chicago, IL). Qualitative data were given as frequency and percentage, while quantitative data were given as median, mean, standard deviation, and minimum/maximum values. The likelihood ratio of a positive test (LR +), the likelihood ratio of a negative test (LR −), the negative predictive value, the positive predictive value, sensitivity, and specificity were calculated using a 2 × 2 table with 95%
confidence intervals. Interclass coefficient was used to compare the fracture displacement measurements taken with x-ray and US. 3. Results Eighty-nine patients that matched the inclusion criteria were admitted to ED during the study period. Four patients were excluded from the study due to loss of sonographer blindness. US was performed on the remaining 85 patients. One patient’s x-ray was not available on PACS, and this patient was also excluded from the study. Therefore, the study was completed with 84 patients. Thirty-six of the patients were male (42.9%), and the mean age was 36.0 ± 15.0 years (min 14, max 72). The mean time between the injury and admission to the hospital was 11.9 ± 21.3 hours (min 0.5, max 120). Of the injuries, 89.3% resulted from foot inversion, and 10.7% arose from direct trauma to the foot. The median US application time was recorded as 4 minutes (min 2, max 6). Fracture was diagnosed by both US and x-ray in 33 patients. In one patient, US was normal, but an x-ray revealed a nondisplaced avulsion fracture on proximal of the fifth metatarsal. The fracture prevalence was 40.5% (34 patients). Sixteen of the cases had an avulsion fracture (47.1%), 12 cases had a Jones fracture (35.3%), 3 cases had a shaft fracture (8.8%), 2 cases had a distal head fracture (5.9%), and 1 case had a proximal diaphyseal fracture (2.9%). The diagnostic sensitivity of US for the fifth metatarsal fractures was 97.1% (95% CI, 82.9%99.8%), and its specificity was 100% (95% CI, 91.1%-100%). The positive likelihood ratio was infinity, and the negative likelihood ratio was 0.03 (95% CI, 0.01 to 0.21). The positive predictive values and negative predictive values were 100% (95% CI, 97%-100%) and 98% (95% CI, 88.2%-99.9%), respectively. The patients' x-ray and US results are presented in Figs. 1 and 2. In 26 patients who had non-comminuted fractures, the mean displacement was 1.2 ± 0.7 mm (min 0.3, max 2.9) by x-ray and 1.8 ± 1.5 mm (min 0.2, max 5.5) by US. There was a fair agreement between the fracture displacement measured by US and x-ray. (κ: 0.;88, 95% CI, 0.022-0.664). The fifth metatarsal distal epiphysis was detected by x-ray and US in only one (14 years old) of 14 patients who were under 21 year old. There was tenderness in the proximal fifth metatarsal of the patient. Injury was diagnosed as an avulsion fracture by both US and x-ray. 4. Discussion
Fig. 1. A 60-year-old male was admitted to the ED with an ankle sprain. (A) Jones fracture was obvious on the x-ray. (B) The cortical disruptions were identified on the proximal fifth metatarsal (arrow).
In the last 15 years, the application of US for the diagnosis of extremity fractures has grown widely [14,15]. However, to our knowledge, there has been no study reporting the reliability of US for the diagnosis of fifth metatarsal fractures. We found that bedside US performed by the emergency physician has a high sensitivity and specificity for the diagnosis of metatarsal fractures. A recent meta-analysis determined the diagnostic accuracy of bedside US for extremity fractures. [16] Eight studies were evaluated (including injuries to the clavicle and upper and lower extremity fractures in a pediatric population, as well as injuries to the femur, humerus, and hand fractures in adults) in this meta-analysis. The sonographers were not trained in musculoskeletal US for these studies. Patients with open fractures, evident deformities, and neurovascular injury were excluded. The overall sensitivity of US in extremity fractures ranged between 83.3% and 100%, and its specificity ranged between 73% and 100%. The positive LR ranged between 3.2 and 56, while the negative LR ranged between and 0.0 to 0.2. Banal et al studied the accuracy of US for the diagnosis of fifth metatarsal stress fractures in patients who had a normal X-ray [13]. US was performed by an experienced rheumatologist, and MRI was accepted as the gold-standard for stress fracture. “Hypoechoic periosteal elevation,” “cortical disruption,” and “increased vascularity
M. Yesilaras et al. / American Journal of Emergency Medicine 32 (2014) 171–174
173
Fig. 2. A 28-year-old female with a fifth metatarsal avulsion fracture. (A and B) Subtle fracture was seen on the x-ray. (C) The small cortical gaps were identified on the fifth metatarsal (arrow).
around the periosteal lesion on power Doppler” were considered as evidence for fracture diagnosis. In this study, the sensitivity of bedside US of the fifth metatarsal fractures was 83%, the specificity was 76%, the positive predictive value was 59%, the negative predictive value was 92%, the positive LR was 3.45, and the negative LR was 0.22. These data support that US may be used as a reliable diagnostic tool for patients who have a high suspicion of fifth metatarsal stress fractures, even if their x-rays are normal. In our study, the sensitivity and specificity of US for the diagnosis of fractures determined by X-ray were 97.1% and 100%, respectively. Because of its excellent sensitivity and specificity, US should be considered an alternative diagnostic tool for the detection of fifth metatarsal fracture. The fifth metatarsal is suitable for ultrasonographic examination because of its superficial location and smooth cortex. The bone can be easily visualized from multiple planes. Lack of the sesamoid bone and ephyphysial line in the area being examined also contribute to the high accuracy of US. There were no false positive US results. There was only one false-negative patient who had non displacement avulsion fracture on the proximal metatarsal. This patient was discharged from the ED with a short leg splint. Chen et al studied the application of US in monitoring the closed reduction of distal radius fractures [17]. The volar, dorsal, and radial displacements were measured by both x-ray and US and were compared before and after reduction. All of the measured displacements were similar, and there were no significant differences between US and X-ray. In our study, the agreement of displacements measured by X-ray and US was fair. We believe that the measurements performed with US are more accurate than those taken by x-ray since US has the ability to measure the widest gap between the fracture fragments from multiple planes. 4.1. Limitation One limitation of this study is that only one sonographer performed all of the US. For the diagnosis of a fracture, x-ray was used as the gold-standard. We may have overlooked some patients
with occult fractures because of the lower sensitivity of x-ray for metatarsal fractures as compared to computed tomography and MRI [7]. In further prospective studies, MRI or scintigraphy should be used as the gold standard. 5. Conclusion In patients admitted to the ED with foot trauma, bedside US can be used as an appropriate diagnostic tool for fifth metatarsal fractures. References [1] Blankstein A. Ultrasound in the diagnosis of clinical orthopedics: the orthopedic stethoscope. World J Orthop 2011;2(2):13–24. [2] Chan SS. Emergency bedside ultrasound for the diagnosis of rib fractures. Am J Emerg Med 2009;27(5):617–20. [3] Beltrame V, Stramare R, Rebellato N, et al. Sonographic evaluation of bone fractures: a reliable alternative in clinical practice? Clin Imaging 2012;36(3): 203–8. [4] Ang SH, Lee SW, Lam KY. Ultrasound-guided reduction of distal radius fractures. Am J Emerg Med 2010;28(9):1002–8. [5] Yıldırım A, Unlüer EE, Vandenberk N, Karagöz A. The role of bedside ultrasonography for occult scaphoid fractures in the emergency department. Ulus Travma Acil Cerrahi Derg 2013;19(3):241–5. [6] Banerjee R, Florian Nickisch F, et al. Foot Injuries. In: Browner BD, Levine AM, Jupiter JB, et al, editors. Skeletal Trauma: Basic Science, Management, and Reconstruction, 4e. Philadelphia, PA: Saunders Elsevier; 2009. p. 2584–747. [7] Preidler KW, Peicha G, Lajtai G, et al. Conventional radiography, CT, and MR imaging in patients with hyperflexion injuries of the foot: diagnostic accuracy in the detection of bony and ligamentous changes. AJR Am J Roentgenol 1999;173(6):1673–7. [8] Hatch RL, Alsobrook JA, Clugston JR. Diagnosis and management of metatarsal fractures. Am Fam Physician 2007;76(6):817–26. [9] Fusetti C, Poletti PA, Pradel PH, et al. Diagnosis of occult scaphoid fracture with high spatial resolution sonography: a prospective blind study. J Trauma 2005;59(3):67781. [10] Marshburn TH, Legome E, Sargsyan A, et al. Goal-directed ultrasound in the detection of long-bone fractures. J Trauma 2004;57(2):329–32. [11] Tayal VS, Antoniazzi J, Pariyadath M, Norton HJ. Prospective use of ultrasound imaging to detect bony hand injuries in adults. J Ultrasound Med 2007;26(9): 1143–8. [12] Patel DD, Blumberg SM, Crain EF. The utility of bedside ultrasonography in identifying fractures and guiding fracture reduction in children. Pediatr Emerg Care 2009;25(4):221–5.
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[13] Banal F, Gandjbakhch F, Foltz V. Sensitivity and specificity of ultrasonography in early diagnosis of metatarsal bone stress fractures: a pilot study of 37 patients. J Rheumatol 2009;36(8):1715–9. [14] Rabiner JE, Khine H, Avner JR, et al. Accuracy of point-of-care ultrasonography for diagnosis of elbow fractures in children. Ann Emerg Med 2013;61(1):9–17. [15] Patil P, Dasgupta B. Role of diagnostic ultrasound in the assessment of musculoskeletal diseases. Ther Adv Musculoskelet Dis 2012;4(5):341–55.
[16] Joshi N, Lira A, Mehta N, et al. Diagnostic accuracy of history, physical examination, and bedside ultrasound for diagnosis of extremity fractures in the emergency department: a systematic review. Acad Emerg Med 2013;20(1): 1–15. [17] Chern TC, Jou IM, Lai KA. Sonography for monitoring closed reduction of displaced extra-articular distal radial fractures. J Bone Joint Surg Am 2002;84A(2):194–203.
