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Original article
Sensitivity and specificity of bedside ultrasonography in the diagnosis of fractures of the fifth metacarpal Ersin Aksay,1 Murat Yesilaras,1 Turgay Yılmaz Kılıc,1 Feriyde Calıskan Tur,1 Mustafa Sever,1 Ahmet Kaya2 1
Department of Emergency Medicine, Izmir Tepecik Research and Educational Hospital, Izmir, Turkey 2 Department of Orthopaedic Surgery, Izmir Tepecik Research and Educational Hospital, Izmir, Turkey Correspondence to Dr Ersin Aksay, Department of Emergency Medicine, İzmir Tepecik Research and Educational Hospital, İzmir 35120, Turkey; [email protected] Received 24 June 2013 Revised 13 August 2013 Accepted 8 October 2013 Published Online First 23 October 2013
ABSTRACT Objectives Ultrasonography is becoming increasingly common in the diagnosis of fracture in emergency medicine. The aim of our study was to investigate the diagnostic accuracy of sonographic examinations for diagnosing fifth metacarpal fractures. Methods A prospective study was performed of consecutive patients aged >14 years admitted to the emergency department with hand trauma and tenderness over the fifth metacarpal. Anteroposterior and oblique plain x-rays were taken on all patients. Emergency physicians performed bedside sonographic examination. The x-rays were reported by an orthopaedic surgeon who was blinded to the sonographic examination findings. The orthopaedic surgeon’s report was considered the gold standard unless a CT scan was performed. In the single case where this occurred, the CT scan report was considered the gold standard. Results Eighty one patients were included in the study, 39 of whom had fractures. Sonographic examination identified the fractures in 38 patients. One occult fracture undetected by plain radiography, later shown on CT scan, was identified by sonographic examination. There were three cases with false positive ultrasound findings. The sensitivity of the diagnosis of fifth metacarpal fractures by ultrasonography was 97.4% (95% CI 84.9% to 99.9%), specificity was 92.9% (95% CI 79.4% to 98.1%), positive likelihood ratio (LR) was 14 (95% CI 4.58 to 41), negative LR was 0.03 (95% CI 0.00 to 0.19), negative predictive value was 97.5% (95% CI 85.3% to 99.9%) and positive predictive value was 92.6% (95% CI 79% to 98.1%). Conclusions Sonographic examination can be used as an effective diagnostic tool in patients with fifth metacarpal trauma. INTRODUCTION The use of ultrasonography in the diagnosis of musculoskeletal injuries is becoming increasingly common. Ultrasonography has been reported to be an effective tool for the diagnosis of fractures of the humerus, sternum, femur, clavicle and forearm.1–3 Fractures in the fifth metacarpal are commonly seen in emergency departments (EDs). However, according to our literature search, there have been no studies focusing on the diagnostic sensitivity of ultrasonography in such cases. The aim of our study was to investigate the diagnostic accuracy of sonographic examination in the diagnosis of fifth metacarpal fractures.
To cite: Aksay E, Yesilaras M, Kılıc TY, et al. Emerg Med J 2015;32: 221–225.
METHODS Our prospective study was conducted between September 2012 and June 2013 in an urban level 3
ED with a rate of nearly 200 000 annual admissions. Consecutive patients aged >14 years admitted to the ED within 1 week of hand trauma with tenderness over the fifth metacarpal were included in the study. These patients underwent anteroposterior and oblique x-ray as well as sonographic examination. Sonographic examination was performed by one of the five emergency medicine specialists participating in the study using a 7.5– 10 MHz linear probe (Mindray M5 colour diagnostic ultrasound system, China). The fifth metacarpal was visualised in the longitudinal (dorsal, oblique and ventral aspects) and transverse (dorsal and ventral aspects) planes. The sonographers were blinded to the x-ray findings. Cortical disruption observed in the sonographic examination was considered to be a fracture. One of the emergency medicine specialists participating in the study was experienced in ultrasonography and provided 1 h of theoretical training regarding fracture ultrasonography to the other participating sonographers. After the sonographers had diagnosed fracture of the fifth metacarpal by sonographic examination in at least three cases that were confirmed by direct radiography (test patients), they began receiving patients into the study. In patients with sonographic evidence of fracture who had normal x-rays but had a high clinical suspicion for fracture, CT was performed at the discretion of the emergency physician. The x-rays were reported by an orthopaedic surgeon who was blinded to the sonographic examination findings, mechanism of trauma, maximal location of tenderness on the fifth metacarpal, physical examination findings and patient management. The opinion of the orthopaedic surgeon was considered the gold standard for diagnosis. The exclusion criteria for the study were as follows: (1) patient did not want to participate in the study; (2) x-rays or sonographic examination were not performed for any reason; (3) patient admitted to the ED when no sonographers were present in the hospital; (4) open wounds in the area of tenderness; (5) patient admitted to the ED ≥7 days after the trauma; (6) the sonographers were unblinded to the x-rays. Statistical analyses were performed using SPSS V.16.0.1 software (SPSS, Chicago, Illinois,, USA). Qualitative data are presented as the number of observations and percentage while quantitative data are presented as mean±SD and (minimummaximum). Standard 2×2 tables were used to measure sensitivity, specificity, accuracy, likelihood ratio of a positive test (LR+), LR for negative test (LR−), negative predictive value and positive predictive value.
Aksay E, et al. Emerg Med J 2015;32:221–225. doi:10.1136/emermed-2013-202971
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Original article Table 1 Characteristics of study patients (n=81) Characteristics Age, years, median (IQR) Male, % Prevalence, % (95% CI) Right-sided injury, % Trauma mechanism, % Punch injury Fall Crush injury Physical examination, % Swelling Bruising Sensitivity, % (95% CI) Specificity, % (95% CI) NPV, % (95% CI) PPV, % (95% CI) LR(+), (95% CI) LR(−), (95% CI)
28 (19–35) 86.4 48.2 (37 to 59.5) 66.7 50.6 33.3 16.1 66.7 25.9 97.4 (84.9 to 99.9) 92.9 (79.4 to 98.1) 97.5 (85.3 to 99.9) 92.6 (79 to 98.1) 14 (4.58 to 41) 0.03 (0.00 to 0.19)
LR, likelihood ratio; NPV, negative predictive value; PPV, positive predictive value.
RESULTS During the study period 130 patients were admitted to the ED with tenderness in the fifth metacarpal. Forty-nine patients were excluded from the study for the following reasons: no sonographers in the ED at the time of admission (37 patients); presence of an open wound (6 patients); admission to the ED 7 days after trauma (2 patients); loss of evaluator blindness (1 patient); unwillingness to participate in the study (1 patient); unable to obtain x-rays (1 patient); and unable to perform sonographic examination (1 patient). Thus, 81 patients were included in the study. The characteristics of the study patients are shown in table 1. In 38 cases fractures were revealed by x-rays. CT was performed in one patient whose sonographic examination showed fractures but direct x-rays were normal. In this case an occult fracture was detected in the proximal end of the fifth metacarpal. The pretest probability of metacarpal fracture in patients presenting with fifth metacarpal tenderness was 48.2% (95% CI 37% to 59.5%). Among the 39 patients with fractures, 38 were also diagnosed by sonographic examination. In 42 patients, radiography did not detect a fracture. There were three cases with false positive ultrasound findings. Cortical disruption was identified in all cases with a positive sonographic examination for fracture. In 69.2% of the cases a
local haematoma associated with the fracture was detected. The locations of the fractures were as follows: 66.7% in the distal end, 10.2% in the shaft and 23.1% in the proximal end. Direct radiographic and sonographic images of three patients with fractures are shown in figures 1–3. Scans conducted by each of the sonographers according to level of experience and results are shown in figure 4. In 42% of the cases an orthopaedic consultation was requested. Casts were applied to 64.2% of the patients. One patient with a proximal fifth metacarpal fracture was admitted to the hospital and underwent surgery; the remaining patients were discharged from the ED.
DISCUSSION The use of ultrasonography in the diagnosis of fractures has become increasingly popular in recent years. Ultrasonography has been shown to be highly sensitive in the diagnosis of fractures of the ribs, ankle, femur, clavicle and scaphoid.3–6 Metacarpal fractures are one of the most common fractures of the hand; traditionally, the definitive diagnosis is made by direct radiography. No studies reported in the literature have investigated the sensitivity of ultrasonographic examination in the diagnosis of fifth metacarpal fractures. Our study revealed that ultrasonography has a high sensitivity in the diagnosis of metacarpal fractures. Although direct radiography is the most commonly used imaging technique in the diagnosis of fractures, there are several disadvantages including radiation exposure and increased ED waiting times. On the other hand, ultrasonography has significant advantages such as easy implementation, repeatability and no exposure to ionising radiation. Since ultrasonography can be completed in a short period of time and can be used at the bedside, it can shorten the ED stay of patients. In addition, bones can be scanned from different angles (volar, dorsal, oblique) and different planes (longitudinal and transverse) in real time, which is also an important advantage. Moreover, ultrasonography can provide information about local haematomas near the fracture and tendon and vascular injuries accompanying the fractures. Ultrasonography has also been used to guide fracture reduction.7 Several authors have reviewed the accuracy of ultrasonography in diagnosing long bone fractures (table 2).7–17 A single prospective study evaluated the diagnosis of hand fractures in adults using ultrasonography.8 In this study there were 78 patients with hand injuries, with fractures detected in 30. Among these 30 patients, 20 had metacarpal fractures, 10 had phalangeal fractures and 1 had concurrent phalangeal and
Figure 1 Occult proximal fifth metacarpal fracture not detected with x-rays but identified by CT. (A) Direct anteroposterior x-ray. (B) Coronal CT cross-section (arrow indicates fracture). (C) Sonographic examination with longitudinal plane (arrow indicates cortical disruption). 222
Aksay E, et al. Emerg Med J 2015;32:221–225. doi:10.1136/emermed-2013-202971
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Original article
Figure 2 A young adult male was admitted after punching. (A) Boxer’s fracture is seen on the x-ray (arrows). (B) Ultrasound image in longitudinal plane (arrow indicates cortical disruption).
Figure 3 A teenage male was admitted after punching. (A) Fracture in the body of the fifth metacarpal is seen on the x-ray (arrowhead). (B) Ultrasound image in longitudinal plane (arrow indicates cortical disruption and the arrowhead indicates an epiphyseal growth plate). metacarpal fractures. Nineteen of the metacarpal fractures were detected by ultrasonography (sensitivity 90.4%). Of the two remaining missed cases, one had fractures in the base of the first metacarpal while the other had a spiral non-displaced fracture of the third metacarpal. There were no false positive sonographic examinations. Among all the cases with metacarpal fractures, 10 were fractures of the fifth metacarpal and all
of these cases were diagnosed by ultrasonography (sensitivity 100%). Ultrasonography has also been used to diagnose occult paediatric ankle and wrist fractures as well as adult scaphoid and rib fractures that could not be detected by direct radiography.4–6 In our study one occult fracture that could not be detected by x-rays was detected by ultrasonography. The excellent sensitivity
Figure 4 Scans conducted by each of the sonographers according to level of experience and results.
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Original article Table 2 Characteristics of studies on the sonographic diagnosis of long bone fractures Author (year)
Bones examined
Population
Sample (n)
Prevalence (%)
Sensitivity % (95% CI)
Specificity % (95% CI)
LR (+) (95% CI)
LR (−) (95% CI)
Marshburn (2004) Tayal (2007) Chen (2007) Patel (2009) Cross (2010) Ackermann (2010) Sinha (2011) Chien (2011) Chaar- Alvarez (2011) Eckert (2012) Rabiner (2013)
Femur/humerus Hand Forearm Extremity Clavicle Proximal humerus Extremity Clavicle Distal forearm Distal forearm Elbow
Adult Adult Paediatric Paediatric Paediatric Juvenile Paediatric Paediatric Paediatric Paediatric Paediatric
58 78 68 33 100 33 41 58 101 115 130
48 40 71 61 43 55 22 67 46 54 33
93 90 97 97 95 94 89 90 96 95 98
83 98 100 93 96 100 100 89 93 98 70
– – – – 27 (7 to 106) – 56.1 8.33 – – 3.3 (2.4 to 4.5)
– – – – 0.05 (0.01 to 0.19) – 0.2 0.11 – – 0.03 (0.01 to 0.23)
(77 to (74 to (89 to (85 to (83 to
99) 97) 100) 100) 99)
(51 to 99) (76 to 97) (85 to 99) (88 to 100)
(65 to (95 to (83 to (74 to (87 to
94) 100) 100) 99) 99)
(87 to 100) (67 to 99) (82 to 98) (60 to 79)
LR, likelihood ratio.
in diagnosing fractures in the fifth metacarpal carried out by five emergency medicine specialists who had not previously received any specific training in musculoskeletal ultrasonography suggests that ultrasound can be used as an alternative tool for the diagnosis of fifth metacarpal fractures. Definitive fracture findings on sonographic examination are cortical disruption or abnormal cortical angulation. Subperiosteal haematomas, bending signs (deformation of the cortex without gapping) and reverberating echoes (increase in medullary echogenicity) are also common sonographic findings in incomplete paediatric fractures such as greenstick and torus fractures and plastic deformity.1 There are potential situations that could lead to false positive results in sonographic examination. For example, if there is a previous fracture in the area being examined, it may be difficult to determine whether the fracture is new or old. Moreover, sesamoid bones in the area of examination can be incorrectly diagnosed as fractures in ultrasonography, although they can be easily detected using direct radiography. In our study all the false positive sonographic examinations were associated with sonographer error (misinterpretation of the irregular surface of the distal end of the fifth metacarpal as a fracture). With sonographic examination we missed only one patient with a proximal fifth metacarpal fracture. In this case the fracture line was located on the medial surface of the proximal fifth metacarpal. Imaging of this area by ultrasonography is very difficult from the dorsal, lateral oblique and ventral aspects of the fifth metacarpal. According to our experience with ultrasonography, the distal end and shaft of the fifth metacarpal are generally more easily visualised than the proximal end. One of the biggest disadvantages of ultrasonography is operator dependence of the examination. In our study, all of the false positive and false negative sonographic examinations were performed by at least experienced sonographers of the study. Cross et al9 reported that the inter-rater reliability (κ) of sonographic diagnosis of paediatric clavicle fractures was 0.74. Moreover, in paediatric forearm fractures the inter-rater reliability was reported to be 0.57.12 There is an insufficient number of studies investigating the inter-rater reliability of ultrasonographers in fracture diagnosis and this should be investigated in future studies. One of the limitations of our study is that it is a single-centre study. No data were collected regarding the duration or the degree of difficulty of the sonographic examinations. In some patients the physician who examined the patient also performed the sonographic examination. This situation may have led the physician to 224
a more detailed examination of the region where the patient indicated most of the pain was felt. Data derived from our study should not be generalised to open fractures, the metacarpals other than the fifth metacarpal or the paediatric population. In our study only one patient underwent a CT as a gold standard imaging test. A future study should consider using CT for all cases with discrepancy between ultrasonography and x-rays.
CONCLUSION Sonographic examination is very sensitive in the diagnosis of fractures in patients admitted to the ED with fifth metacarpal trauma. Ultrasonography can be used as an effective diagnostic tool in the detection of fractures of the fifth metacarpal. Contributors EA, MY, TYK, FCT, MS and AK contributed to the planning, conducting and reporting of the manuscript. EA is responsible for the overall content as guarantor. Competing interests None. Patient consent Obtained. Ethics approval Ethics approval was obtained from the local ethics committee. Provenance and peer review Not commissioned; externally peer reviewed.
REFERENCES 1 2 3
4 5 6 7 8 9 10 11 12
Ekşioğlu F, Altinok D, Uslu MM, et al. Sonographic findings in pediatric fractures. Turk J Pediatr 2003;45:136–40. You JS, Chung YE, Kim D, et al. Role of sonography in the emergency room to diagnose sternal fractures. J Clin Ultrasound 2010;38:135–7. 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;20:1–15. Turk F, Kurt AB, Saglam S. Evaluation by ultrasound of traumatic rib fractures missed by radiography. Emerg Radiol 2010;17:473–7. Platon A, Poletti PA, Van Aaken J, et al. Occult fractures of the scaphoid: the role of ultrasonography in the emergency department. Skeletal Radiol 2011;40:869–75. Simanovsky N, Lamdan R, Hiller N, et al. Sonographic detection of radiographically occult fractures in pediatric ankle and wrist injuries. J Pediatr Orthop 2009;29:142–5. Chen L, Kim Y, Moore CL. Diagnosis and guided reduction of forearm fractures in children using bedside ultrasound. PediatrEmerg Care 2007;23:528–31. Tayal VS, Antoniazzi J, Pariyadath M, et al. Prospective use of ultrasound imaging to detect bony hand injuries in adults. J Ultrasound Med 2007;26:1143–8. Cross KP, Warkentine FH, Kim IK, et al. Bedside ultrasound diagnosis of clavicle fractures in the pediatric emergency department. Acad Emerg Med 2010;17:687–93. Chien M, Bulloch B, Garcia-Filion P, et al. Bedside ultrasound in the diagnosis of pediatric clavicle fractures. Pediatr Emerg Care 2011;27:1038–41. Marshburn TH, Legome E, Sargsyan A, et al. Goal-directed ultrasound in the detection of long-bone fractures. J Trauma 2004;57:329–32. Chaar-Alvarez FM, Warkentine F, Cross K, et al. Bedside ultrasound diagnosis of non angulated distal forearm fractures in the pediatric emergency department. Pediatr Emerg Care 2011;27:1027–32.
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Original article 13
14
Sinha TP, Bhoi S, Kumar S, et al. Diagnostic accuracy of bedside emergency ultrasound screening for fractures in pediatric trauma patients. J Emerg Trauma Shock 2011;4:443–5. Patel DD, Blumberg SM, Crain EF. The utility of bedside ultrasonography in identifying fractures and guiding fracture reduction in children. Pediatr Emerg Care 2009;25:221–25.
Aksay E, et al. Emerg Med J 2015;32:221–225. doi:10.1136/emermed-2013-202971
15
16 17
Eckert K, Ackermann O, Schweiger B, et al. Ultrasound as a viable alternative to standard X-rays for the diagnosis of distal forearm fractures in children. Z Orthop Unfall 2012;150:409–14. Ackermann O, Sesia S, Berberich T, et al. Sonographic diagnostics of proximal humerus fractures in juveniles. Unfallchirurg 2010;113:839–42. 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;61:9–17.
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Sensitivity and specificity of bedside ultrasonography in the diagnosis of fractures of the fifth metacarpal Ersin Aksay, Murat Yesilaras, Turgay Yilmaz Kilic, Feriyde Caliskan Tur, Mustafa Sever and Ahmet Kaya Emerg Med J 2015 32: 221-225 originally published online October 23, 2013
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Original article
Sensitivity and specificity of bedside ultrasonography in the diagnosis of fractures of the fifth metacarpal Ersin Aksay,1 Murat Yesilaras,1 Turgay Yılmaz Kılıc,1 Feriyde Calıskan Tur,1 Mustafa Sever,1 Ahmet Kaya2 1
Department of Emergency Medicine, Izmir Tepecik Research and Educational Hospital, Izmir, Turkey 2 Department of Orthopaedic Surgery, Izmir Tepecik Research and Educational Hospital, Izmir, Turkey Correspondence to Dr Ersin Aksay, Department of Emergency Medicine, İzmir Tepecik Research and Educational Hospital, İzmir 35120, Turkey; [email protected] Received 24 June 2013 Revised 13 August 2013 Accepted 8 October 2013 Published Online First 23 October 2013
ABSTRACT Objectives Ultrasonography is becoming increasingly common in the diagnosis of fracture in emergency medicine. The aim of our study was to investigate the diagnostic accuracy of sonographic examinations for diagnosing fifth metacarpal fractures. Methods A prospective study was performed of consecutive patients aged >14 years admitted to the emergency department with hand trauma and tenderness over the fifth metacarpal. Anteroposterior and oblique plain x-rays were taken on all patients. Emergency physicians performed bedside sonographic examination. The x-rays were reported by an orthopaedic surgeon who was blinded to the sonographic examination findings. The orthopaedic surgeon’s report was considered the gold standard unless a CT scan was performed. In the single case where this occurred, the CT scan report was considered the gold standard. Results Eighty one patients were included in the study, 39 of whom had fractures. Sonographic examination identified the fractures in 38 patients. One occult fracture undetected by plain radiography, later shown on CT scan, was identified by sonographic examination. There were three cases with false positive ultrasound findings. The sensitivity of the diagnosis of fifth metacarpal fractures by ultrasonography was 97.4% (95% CI 84.9% to 99.9%), specificity was 92.9% (95% CI 79.4% to 98.1%), positive likelihood ratio (LR) was 14 (95% CI 4.58 to 41), negative LR was 0.03 (95% CI 0.00 to 0.19), negative predictive value was 97.5% (95% CI 85.3% to 99.9%) and positive predictive value was 92.6% (95% CI 79% to 98.1%). Conclusions Sonographic examination can be used as an effective diagnostic tool in patients with fifth metacarpal trauma. INTRODUCTION The use of ultrasonography in the diagnosis of musculoskeletal injuries is becoming increasingly common. Ultrasonography has been reported to be an effective tool for the diagnosis of fractures of the humerus, sternum, femur, clavicle and forearm.1–3 Fractures in the fifth metacarpal are commonly seen in emergency departments (EDs). However, according to our literature search, there have been no studies focusing on the diagnostic sensitivity of ultrasonography in such cases. The aim of our study was to investigate the diagnostic accuracy of sonographic examination in the diagnosis of fifth metacarpal fractures.
To cite: Aksay E, Yesilaras M, Kılıc TY, et al. Emerg Med J 2015;32: 221–225.
METHODS Our prospective study was conducted between September 2012 and June 2013 in an urban level 3
ED with a rate of nearly 200 000 annual admissions. Consecutive patients aged >14 years admitted to the ED within 1 week of hand trauma with tenderness over the fifth metacarpal were included in the study. These patients underwent anteroposterior and oblique x-ray as well as sonographic examination. Sonographic examination was performed by one of the five emergency medicine specialists participating in the study using a 7.5– 10 MHz linear probe (Mindray M5 colour diagnostic ultrasound system, China). The fifth metacarpal was visualised in the longitudinal (dorsal, oblique and ventral aspects) and transverse (dorsal and ventral aspects) planes. The sonographers were blinded to the x-ray findings. Cortical disruption observed in the sonographic examination was considered to be a fracture. One of the emergency medicine specialists participating in the study was experienced in ultrasonography and provided 1 h of theoretical training regarding fracture ultrasonography to the other participating sonographers. After the sonographers had diagnosed fracture of the fifth metacarpal by sonographic examination in at least three cases that were confirmed by direct radiography (test patients), they began receiving patients into the study. In patients with sonographic evidence of fracture who had normal x-rays but had a high clinical suspicion for fracture, CT was performed at the discretion of the emergency physician. The x-rays were reported by an orthopaedic surgeon who was blinded to the sonographic examination findings, mechanism of trauma, maximal location of tenderness on the fifth metacarpal, physical examination findings and patient management. The opinion of the orthopaedic surgeon was considered the gold standard for diagnosis. The exclusion criteria for the study were as follows: (1) patient did not want to participate in the study; (2) x-rays or sonographic examination were not performed for any reason; (3) patient admitted to the ED when no sonographers were present in the hospital; (4) open wounds in the area of tenderness; (5) patient admitted to the ED ≥7 days after the trauma; (6) the sonographers were unblinded to the x-rays. Statistical analyses were performed using SPSS V.16.0.1 software (SPSS, Chicago, Illinois,, USA). Qualitative data are presented as the number of observations and percentage while quantitative data are presented as mean±SD and (minimummaximum). Standard 2×2 tables were used to measure sensitivity, specificity, accuracy, likelihood ratio of a positive test (LR+), LR for negative test (LR−), negative predictive value and positive predictive value.
Aksay E, et al. Emerg Med J 2015;32:221–225. doi:10.1136/emermed-2013-202971
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Original article Table 1 Characteristics of study patients (n=81) Characteristics Age, years, median (IQR) Male, % Prevalence, % (95% CI) Right-sided injury, % Trauma mechanism, % Punch injury Fall Crush injury Physical examination, % Swelling Bruising Sensitivity, % (95% CI) Specificity, % (95% CI) NPV, % (95% CI) PPV, % (95% CI) LR(+), (95% CI) LR(−), (95% CI)
28 (19–35) 86.4 48.2 (37 to 59.5) 66.7 50.6 33.3 16.1 66.7 25.9 97.4 (84.9 to 99.9) 92.9 (79.4 to 98.1) 97.5 (85.3 to 99.9) 92.6 (79 to 98.1) 14 (4.58 to 41) 0.03 (0.00 to 0.19)
LR, likelihood ratio; NPV, negative predictive value; PPV, positive predictive value.
RESULTS During the study period 130 patients were admitted to the ED with tenderness in the fifth metacarpal. Forty-nine patients were excluded from the study for the following reasons: no sonographers in the ED at the time of admission (37 patients); presence of an open wound (6 patients); admission to the ED 7 days after trauma (2 patients); loss of evaluator blindness (1 patient); unwillingness to participate in the study (1 patient); unable to obtain x-rays (1 patient); and unable to perform sonographic examination (1 patient). Thus, 81 patients were included in the study. The characteristics of the study patients are shown in table 1. In 38 cases fractures were revealed by x-rays. CT was performed in one patient whose sonographic examination showed fractures but direct x-rays were normal. In this case an occult fracture was detected in the proximal end of the fifth metacarpal. The pretest probability of metacarpal fracture in patients presenting with fifth metacarpal tenderness was 48.2% (95% CI 37% to 59.5%). Among the 39 patients with fractures, 38 were also diagnosed by sonographic examination. In 42 patients, radiography did not detect a fracture. There were three cases with false positive ultrasound findings. Cortical disruption was identified in all cases with a positive sonographic examination for fracture. In 69.2% of the cases a
local haematoma associated with the fracture was detected. The locations of the fractures were as follows: 66.7% in the distal end, 10.2% in the shaft and 23.1% in the proximal end. Direct radiographic and sonographic images of three patients with fractures are shown in figures 1–3. Scans conducted by each of the sonographers according to level of experience and results are shown in figure 4. In 42% of the cases an orthopaedic consultation was requested. Casts were applied to 64.2% of the patients. One patient with a proximal fifth metacarpal fracture was admitted to the hospital and underwent surgery; the remaining patients were discharged from the ED.
DISCUSSION The use of ultrasonography in the diagnosis of fractures has become increasingly popular in recent years. Ultrasonography has been shown to be highly sensitive in the diagnosis of fractures of the ribs, ankle, femur, clavicle and scaphoid.3–6 Metacarpal fractures are one of the most common fractures of the hand; traditionally, the definitive diagnosis is made by direct radiography. No studies reported in the literature have investigated the sensitivity of ultrasonographic examination in the diagnosis of fifth metacarpal fractures. Our study revealed that ultrasonography has a high sensitivity in the diagnosis of metacarpal fractures. Although direct radiography is the most commonly used imaging technique in the diagnosis of fractures, there are several disadvantages including radiation exposure and increased ED waiting times. On the other hand, ultrasonography has significant advantages such as easy implementation, repeatability and no exposure to ionising radiation. Since ultrasonography can be completed in a short period of time and can be used at the bedside, it can shorten the ED stay of patients. In addition, bones can be scanned from different angles (volar, dorsal, oblique) and different planes (longitudinal and transverse) in real time, which is also an important advantage. Moreover, ultrasonography can provide information about local haematomas near the fracture and tendon and vascular injuries accompanying the fractures. Ultrasonography has also been used to guide fracture reduction.7 Several authors have reviewed the accuracy of ultrasonography in diagnosing long bone fractures (table 2).7–17 A single prospective study evaluated the diagnosis of hand fractures in adults using ultrasonography.8 In this study there were 78 patients with hand injuries, with fractures detected in 30. Among these 30 patients, 20 had metacarpal fractures, 10 had phalangeal fractures and 1 had concurrent phalangeal and
Figure 1 Occult proximal fifth metacarpal fracture not detected with x-rays but identified by CT. (A) Direct anteroposterior x-ray. (B) Coronal CT cross-section (arrow indicates fracture). (C) Sonographic examination with longitudinal plane (arrow indicates cortical disruption). 222
Aksay E, et al. Emerg Med J 2015;32:221–225. doi:10.1136/emermed-2013-202971
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Original article
Figure 2 A young adult male was admitted after punching. (A) Boxer’s fracture is seen on the x-ray (arrows). (B) Ultrasound image in longitudinal plane (arrow indicates cortical disruption).
Figure 3 A teenage male was admitted after punching. (A) Fracture in the body of the fifth metacarpal is seen on the x-ray (arrowhead). (B) Ultrasound image in longitudinal plane (arrow indicates cortical disruption and the arrowhead indicates an epiphyseal growth plate). metacarpal fractures. Nineteen of the metacarpal fractures were detected by ultrasonography (sensitivity 90.4%). Of the two remaining missed cases, one had fractures in the base of the first metacarpal while the other had a spiral non-displaced fracture of the third metacarpal. There were no false positive sonographic examinations. Among all the cases with metacarpal fractures, 10 were fractures of the fifth metacarpal and all
of these cases were diagnosed by ultrasonography (sensitivity 100%). Ultrasonography has also been used to diagnose occult paediatric ankle and wrist fractures as well as adult scaphoid and rib fractures that could not be detected by direct radiography.4–6 In our study one occult fracture that could not be detected by x-rays was detected by ultrasonography. The excellent sensitivity
Figure 4 Scans conducted by each of the sonographers according to level of experience and results.
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Original article Table 2 Characteristics of studies on the sonographic diagnosis of long bone fractures Author (year)
Bones examined
Population
Sample (n)
Prevalence (%)
Sensitivity % (95% CI)
Specificity % (95% CI)
LR (+) (95% CI)
LR (−) (95% CI)
Marshburn (2004) Tayal (2007) Chen (2007) Patel (2009) Cross (2010) Ackermann (2010) Sinha (2011) Chien (2011) Chaar- Alvarez (2011) Eckert (2012) Rabiner (2013)
Femur/humerus Hand Forearm Extremity Clavicle Proximal humerus Extremity Clavicle Distal forearm Distal forearm Elbow
Adult Adult Paediatric Paediatric Paediatric Juvenile Paediatric Paediatric Paediatric Paediatric Paediatric
58 78 68 33 100 33 41 58 101 115 130
48 40 71 61 43 55 22 67 46 54 33
93 90 97 97 95 94 89 90 96 95 98
83 98 100 93 96 100 100 89 93 98 70
– – – – 27 (7 to 106) – 56.1 8.33 – – 3.3 (2.4 to 4.5)
– – – – 0.05 (0.01 to 0.19) – 0.2 0.11 – – 0.03 (0.01 to 0.23)
(77 to (74 to (89 to (85 to (83 to
99) 97) 100) 100) 99)
(51 to 99) (76 to 97) (85 to 99) (88 to 100)
(65 to (95 to (83 to (74 to (87 to
94) 100) 100) 99) 99)
(87 to 100) (67 to 99) (82 to 98) (60 to 79)
LR, likelihood ratio.
in diagnosing fractures in the fifth metacarpal carried out by five emergency medicine specialists who had not previously received any specific training in musculoskeletal ultrasonography suggests that ultrasound can be used as an alternative tool for the diagnosis of fifth metacarpal fractures. Definitive fracture findings on sonographic examination are cortical disruption or abnormal cortical angulation. Subperiosteal haematomas, bending signs (deformation of the cortex without gapping) and reverberating echoes (increase in medullary echogenicity) are also common sonographic findings in incomplete paediatric fractures such as greenstick and torus fractures and plastic deformity.1 There are potential situations that could lead to false positive results in sonographic examination. For example, if there is a previous fracture in the area being examined, it may be difficult to determine whether the fracture is new or old. Moreover, sesamoid bones in the area of examination can be incorrectly diagnosed as fractures in ultrasonography, although they can be easily detected using direct radiography. In our study all the false positive sonographic examinations were associated with sonographer error (misinterpretation of the irregular surface of the distal end of the fifth metacarpal as a fracture). With sonographic examination we missed only one patient with a proximal fifth metacarpal fracture. In this case the fracture line was located on the medial surface of the proximal fifth metacarpal. Imaging of this area by ultrasonography is very difficult from the dorsal, lateral oblique and ventral aspects of the fifth metacarpal. According to our experience with ultrasonography, the distal end and shaft of the fifth metacarpal are generally more easily visualised than the proximal end. One of the biggest disadvantages of ultrasonography is operator dependence of the examination. In our study, all of the false positive and false negative sonographic examinations were performed by at least experienced sonographers of the study. Cross et al9 reported that the inter-rater reliability (κ) of sonographic diagnosis of paediatric clavicle fractures was 0.74. Moreover, in paediatric forearm fractures the inter-rater reliability was reported to be 0.57.12 There is an insufficient number of studies investigating the inter-rater reliability of ultrasonographers in fracture diagnosis and this should be investigated in future studies. One of the limitations of our study is that it is a single-centre study. No data were collected regarding the duration or the degree of difficulty of the sonographic examinations. In some patients the physician who examined the patient also performed the sonographic examination. This situation may have led the physician to 224
a more detailed examination of the region where the patient indicated most of the pain was felt. Data derived from our study should not be generalised to open fractures, the metacarpals other than the fifth metacarpal or the paediatric population. In our study only one patient underwent a CT as a gold standard imaging test. A future study should consider using CT for all cases with discrepancy between ultrasonography and x-rays.
CONCLUSION Sonographic examination is very sensitive in the diagnosis of fractures in patients admitted to the ED with fifth metacarpal trauma. Ultrasonography can be used as an effective diagnostic tool in the detection of fractures of the fifth metacarpal. Contributors EA, MY, TYK, FCT, MS and AK contributed to the planning, conducting and reporting of the manuscript. EA is responsible for the overall content as guarantor. Competing interests None. Patient consent Obtained. Ethics approval Ethics approval was obtained from the local ethics committee. Provenance and peer review Not commissioned; externally peer reviewed.
REFERENCES 1 2 3
4 5 6 7 8 9 10 11 12
Ekşioğlu F, Altinok D, Uslu MM, et al. Sonographic findings in pediatric fractures. Turk J Pediatr 2003;45:136–40. You JS, Chung YE, Kim D, et al. Role of sonography in the emergency room to diagnose sternal fractures. J Clin Ultrasound 2010;38:135–7. 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;20:1–15. Turk F, Kurt AB, Saglam S. Evaluation by ultrasound of traumatic rib fractures missed by radiography. Emerg Radiol 2010;17:473–7. Platon A, Poletti PA, Van Aaken J, et al. Occult fractures of the scaphoid: the role of ultrasonography in the emergency department. Skeletal Radiol 2011;40:869–75. Simanovsky N, Lamdan R, Hiller N, et al. Sonographic detection of radiographically occult fractures in pediatric ankle and wrist injuries. J Pediatr Orthop 2009;29:142–5. Chen L, Kim Y, Moore CL. Diagnosis and guided reduction of forearm fractures in children using bedside ultrasound. PediatrEmerg Care 2007;23:528–31. Tayal VS, Antoniazzi J, Pariyadath M, et al. Prospective use of ultrasound imaging to detect bony hand injuries in adults. J Ultrasound Med 2007;26:1143–8. Cross KP, Warkentine FH, Kim IK, et al. Bedside ultrasound diagnosis of clavicle fractures in the pediatric emergency department. Acad Emerg Med 2010;17:687–93. Chien M, Bulloch B, Garcia-Filion P, et al. Bedside ultrasound in the diagnosis of pediatric clavicle fractures. Pediatr Emerg Care 2011;27:1038–41. Marshburn TH, Legome E, Sargsyan A, et al. Goal-directed ultrasound in the detection of long-bone fractures. J Trauma 2004;57:329–32. Chaar-Alvarez FM, Warkentine F, Cross K, et al. Bedside ultrasound diagnosis of non angulated distal forearm fractures in the pediatric emergency department. Pediatr Emerg Care 2011;27:1027–32.
Aksay E, et al. Emerg Med J 2015;32:221–225. doi:10.1136/emermed-2013-202971
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Original article 13
14
Sinha TP, Bhoi S, Kumar S, et al. Diagnostic accuracy of bedside emergency ultrasound screening for fractures in pediatric trauma patients. J Emerg Trauma Shock 2011;4:443–5. Patel DD, Blumberg SM, Crain EF. The utility of bedside ultrasonography in identifying fractures and guiding fracture reduction in children. Pediatr Emerg Care 2009;25:221–25.
Aksay E, et al. Emerg Med J 2015;32:221–225. doi:10.1136/emermed-2013-202971
15
16 17
Eckert K, Ackermann O, Schweiger B, et al. Ultrasound as a viable alternative to standard X-rays for the diagnosis of distal forearm fractures in children. Z Orthop Unfall 2012;150:409–14. Ackermann O, Sesia S, Berberich T, et al. Sonographic diagnostics of proximal humerus fractures in juveniles. Unfallchirurg 2010;113:839–42. 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;61:9–17.
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Sensitivity and specificity of bedside ultrasonography in the diagnosis of fractures of the fifth metacarpal Ersin Aksay, Murat Yesilaras, Turgay Yilmaz Kilic, Feriyde Caliskan Tur, Mustafa Sever and Ahmet Kaya Emerg Med J 2015 32: 221-225 originally published online October 23, 2013
doi: 10.1136/emermed-2013-202971 Updated information and services can be found at: http://emj.bmj.com/content/32/3/221
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