Findings
The radiographs are normal. MRI demonstrates marrow edema pattern (high IR, low T1) of the right C6 lateral mass. Axial T2 MRI images show a different signal intensity of the right as compared to left C6 lateral mass. CT shows a subtle lucency of the right C6 lateral mass with surrounding sclerosis about the junction of the superior and inferior facets.
Diagnosis: Cervical Spondylolysis
A very rare diagnosis and one neither myself nor my colleagues had ever seen. Lumbar posterior element abnormalities/fractures are very common but in the cervical spine, it is extremely uncommon. There have been reports about cases in American football but given the overall low prevalence of this injury, it is likely but hard to know if some activity from the patient playing squash is the cause. As in this case, this entity most frequently involves C6. There is a fracture of the lateral/articular mass at the junction of the superior and inferior facets, again as seen in this case.
Little is known about the etiology but most favored is an overuse injury with shear stress of the articular mass at C6. There may be an underlying developmental component, but no true congenital case has been reported. These patients are thought to be at risk for cord injury at this level but this again, has not been proven. Given the infrequent nature of this injury the management is still not well delineated. This particularly relates to when or if to return to especially contact sports.
References
Timothy B. Alton MD, Amit M. Patel MD, Michael J. Lee MD and Jens R. Chapman MD. Pediatric cervical spondylolysis and American football. Spine Journal, The, 2014-06-01, Volume 14, Issue 6, Pages e1-e5, Copyright © 2014 Elsevier Inc.