Bilateral spondylolysis of the sixth cervical vertebra

Diagnosis

Bilateral spondylolysis of the sixth cervical vertebra.</<span class="end-tag" />

Findings

The lateral radiograph of the cervical spine showed the presence of a defect of the pars interarticularis at C6. Grade-1 (&lt;25%) spondylolisthesis of C6 anteriorly with respect to C7 was also noted on the lateral view. There was no increase in the prevertebral soft tissue density anterior to C6. Flexion and extension views did not reveal instability of the cervical spine (Figure 1). Additionally, spina bi&#64257;da occulta was observed on the anteroposterior view (Figure 2). </<span class="end-tag" />P
><P

>Axial noncontrast CT at the C6 level showed bilateral well-corticated defects of the pars interarticularis. It also con&#64257;rmed the presence of spina bi&#64257;da occulta and medial displacement of the laminae. Again, soft tissue swelling indicative of acute trauma was not detected (Figure 3). </<span class="end-tag" />P

Discussion

Spondylolysis with spondylolisthesis is a common condition in the lumbar spine. Cervical spondylolysis is, however, much more rare than its lumbar counterpart and is described as a well-corticated cleft between the superior and inferior articular facets of the articular pillar of the cervical spine.<Sup>1,2 </<span class="end-tag" />Sup></<span class="end-tag" />P
><P

>It is usually discovered as an incidental radiologic &#64257;nding in patients who are undergoing cervical spine imaging for neck pain or trauma<Sup>2,3 </<span class="end-tag" />Sup>Associated neurological de&#64257;cit may be detected, although spinal cord compression is rare.<Sup>4 </<span class="end-tag" />Sup>This condition mostly affects the sixth cervical vertebra, although involvement of other cervical vertebrae has been reported.<Sup>5 </<span class="end-tag" />Sup></<span class="end-tag" />P
><P

>Plain-&#64257;lm radiography and CT are the principal diagnostic modalities that help in differentiating cervical spondylolysis from articular pillar fracture or dislocation. In addition to the distinctive pars interarticularis defect, other imaging &#64257;ndings described in cervical spondylolysis are hyposplasia of the pedicles, dysplastic laminae, and spina bi&#64257;da. Medial displacement of inferior facets and laminae, compensatory hypertrophic changes of the articular process in the adjacent vertebrae, and spondylolisthesis are also seen.<Sup>2,6,7 </<span class="end-tag" />Sup>The pars interarticularis defect is dif&#64257;cult to identify on magnetic resonance imaging because of poor bone resolution; however, the absence of the spinous process on sagittal sequences should raise the suspicion of this abnormality.<Sup>2,8 </<span class="end-tag" />Sup></<span class="end-tag" />P
><P

>The exact etiology of cervical spondylolysis remains unknown. The detection of articular dysplasia and spina bi&#64257;da occulta on imaging studies suggests a congenital origin of this condition. A dysplasia mechanism with stress fractures of a weakened pars interarticularis is another possibility.<Sup>3 </<span class="end-tag" />Sup>Patient management is usually conservative, with surgical treatment reserved for patients with a neurologic de&#64257;cit.<Sup>1,2 </<span class="end-tag" />Sup></<span class="end-tag" />P
><p><B>CONCLUSION </<span class="end-tag" />B></<span class="end-tag" />p><P

>Cervical spondylolysis is a rare condition. It is usually discovered incidentally and should be differentiated from traumatic spondylolysis. Plain-&#64257;lm radiography and CT are the main diagnostic imaging modalities.
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type="1"
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