Cervical spondylolysis in a child: a case with hypermobility.

BACKGROUND CONTEXT: Cervical spondylolysis (CS) is a rare disorder involving a cleft in the articular mass, at the junction of the superior and inferior facet joints, and often a complex malformation of the posterior elements of the vertebra. The most commonly affected level is the sixth cervical vertebra. Most of the cases are adults. Its origin, mechanical or embryological, is controversial. PURPOSE: To report the case in a young boy and to outline the imaging findings related to the causal mechanism. STUDY DESIGN: A case report. PATIENT SAMPLE: A 7-year-old boy with CS of the sixth cervical vertebra discovered after a minimal trauma. METHODS: Radiological observation and literature review. RESULTS: A forward listhesis in extension is observed despite an intact disc on magnetic resonance imaging, expressing the loads applied to the dysplastic vertebra before the mechanical failure of the vertebral structures occurs. CONCLUSIONS: A mixed origin, both mechanical and congenital is suggested. It is proposed that the CS results from microimpacts because of the cervical spine biomechanics affecting a posterior arch prone to develop a cleft as a result of associated malformations