Name : Morteza
Family : Sanei Taheri
Affiliation :Radiology Department,Shohada Tajrish Hospital,SBMU
Academic Degree : Associate Professor of Radiology
Resident : Afarin Sadeghian
Head & Neck Imaging
Gender : Male
Age : 55
55-year-old man with a load striking on head
The images show unilateral fractures through the anterior and posterior arches of C1.The C1 ring expands and loses alignment with the adjacent occipital condyles above and C2 below.Bilateral displacement of lateral masses of C1 beyond the lateral margins of articular pillars of C2 along with widened space between the dens and C1-lateral masses are clearly seen.The mentioned findings are consistent with burst fracture of C1 (Jefferson' fracture)with possible rupture of transverse ligaments .As well,C2 bone ring is incomplete due to a fracture involving the base of the odontoid process,compatible with type II of dens fracture.The odontoid peg is displaced posteriorly and a few fracture fragments are seen at posterior and inferior aspect of C2 vertebral body associated with soft tissue swelling at this level.Following the posterior outline of cervical vertebral bodies reveals that is disrupted with the dens fragment and also shows the basion is located posterior to this axial line,indicating mild posterior occipitoatlantal subluxation.On MR images posterior longitudinal ligament is intact and there is no evidence of spinal cord injury or vascular compromise.
C1' Jefferson' fracture associated with type II of dens fracture due to axial compressive loading on cervical spine
Discussion (Related Text)
Accurate diagnosis of acute cervical spine injury requires cooperation between clinician and radiologist, a reliable and repeatable approach to interpreting cervical spine CT, and the awareness that a patient may have a significant and unstable ligamentous injury despite normal findings. Emergency physicians triage patients with suspected cervical spine injury into high- and low-risk groups—that is, those who require imaging for confirmation and accurate evaluation and those who can be confidently discharged.MDCT with thin-section reconstruction and multiplanar reformations identifies the exact location and displacement of fractures and bone fragments and defines the extent of any potential spinal canal, neuroforaminal, or vascular compromise. An accurate clinical history that specifies injury mechanism and location of pain is essential for accurately interpreting subtle findings, particularly in the presence of de- generative disk disease. To avoid search pattern errors, it is helpful to have a checklist in mind that will ensure that all important structures are examined, as outlined in the following subsections.In transaxial Images,examine the integrity and rotational alignment of each vertebra, the cervical soft tissues, spinal canal diameter, and neuroforaminal patency.In midline Sagittal Images,evaluate the prevertebral soft tissues for thickness greater than 5 mm at C2 or 15 mm at C5. The anterior spinal line, posterior spinal line, and spinolaminar line should be continuous, and the interspinous distance should be uniform. The dens-basion distance should be 9.5 mm or less, and a line drawn vertically along the dorsal body of C2 (posterior axial line) should be less than 5.5 mm posterior to the basion. The atlantodental interval should be less than 3 mm in adults. The C1–2 interspinous distance measured at the spinolaminal line should be less than 7.8 mm.In parasagittal Images,the occipital condyles should be intact. The atlantooccipital and atlantoaxial articulations should be congruent and the facets should align normally, with the inferior articulating facet of the upper vertebral body posterior to the superior articulating facet of the adjacent lower vertebral body.In coronal Images,the occipital condyles, C1, and C2 should be intact and aligned. The dens should be centered between the lateral masses of C1.
Legome E, Shockley LW, eds. Trauma: A Comprehensive Emergency Medicine Approach. Cambridge, UK: Cambridge University Press: 2011