Rod Migration to the Thoracic Subarachnoid Space after C1-2 Instrumentation: A Case Report and Literature Review.

Posterior instrumented fusion of the cervical spine is a common surgical procedure in the treatment of cervical subluxation, fractures, and stenosis. Although malpositions are commonly seen, it is rare to observe the malposition of the rod or interconnection because of hardware failure. A 62-year-old woman with spastic tetraparesis as a sequel to pediatric meningitis with C1 -C2 cervical subluxation and myelomalacia had undergone laminectomy of C1 and C1 lateral mass and C2 bilateral pedicular screw fixation. Three years after the stabilization, she presented with complaints of headache, neck pain, and difficulty walking. There was no history of trauma during that period. A previously unrecorded and unusual migration of a rod through the thoracic subarachnoid space was detected. In this study, we report a case of atlantoaxial stabilization using the screw-rod technique that was followed by rod migration to the thoracic subarachnoid space, and outline the subsequent management of the case. Failure of bony fusion can result in micromotion and subsequent migration of fixation device components. Routine radiographic follow-up could be used to identify migration events.