A case report of rod migration into cerebellum through foramen magnum after lateral mass fixation of cervical spine

We report on a rare case of connecting rod migration into the posterior cranial fossa after posterior cervical decompression and lateral mass screw fixation. A 55-year-old male patient who was operated on for ossification of posterior longitudinal ligament complained of sudden-onset giddiness followed by loss of consciousness one and half year following surgery. CT scan showed migration of left-sided connecting rod into the right cerebellum through foramen magnum. The patient was operated on for rod removal but he sustained a cardiorespiratory arrest and died on the eighth postoperative day. Autopsy confirmed damage to the right cerebellum due to rod migration. The clinician should be aware that superior rod migration is a rare but potentially disastrous complication. Regular follow-up with radiological evaluation should be done to look for implant loosening, migration, and non-union even in asymptomatic patients. The implant should be subsequently removed after it has served its purpose.