Bedside Ultrasonography for Early Diagnosis of Occult Radial Head Fractures in Emergency Room: A CTComparative Diagnostic Study

Background: Some of the Mason type I fractures cannot be detected on early radiographic images. These occultfractures are considered as a diagnostic challenge for physicians. Our aim was to determine the value of bedsideultrasonography for the detection of Mason I radial head fractures that are non-visible in early X-ray’s.Methods: A prospective blind single-center diagnostic study was conducted (from June 2012 till May 2013) concerning23 patients who were clinically suspicious of having a radial head fracture. These patients were evaluated with abedside high frequency ultrasound in the Emergency Room (E.R.). The two sonographic criteria that were consideredto be diagnostic for fracture were: a. effusion besides the radial head-neck and b. cortical discontinuity of the radialhead or neck. All patients also underwent a Computed Tomography (CT) as the gold standard imaging modality fordiagnosis of occult radial head fractures.Results: Fifteen out of 23 patients were diagnosed with radial head fracture using both ultrasound and CT. On the otherhand, there were three patients with negative ultrasound and positive CT, in addition two patients were found positive inthe ultrasonographic exam, while this result was not confirmed by the CT scan. In comparison with CT, ultrasound examappeared to have 83.3% sensitivity, 60% specificity, 88.2% positive prognostic value and 50% negative prognosticvalue (when at least one diagnostic sonographic criterion was positive). The accuracy of the sonographic study for thediagnosis of the aforementioned fractures was 78.2%. Effusion in contact with the radial neck was the most sensitivesonographic sign (14/15 of the true positive radial head ultrasounds).Conclusion: Bedside ultrasound in the E.R. was proven to be a sensitive tool for early (day-1) diagnosis of the occultradial head fractures. It could be used as an adjacent imaging modality in patients suspicious for radial head fracture,when the initial X-rays are negative.Level of evidence: II