Repeated complication following atlantoaxial fusion: a case report

Occipital bone erosion induced by C1 pedicle screw as a late complication of atlantoaxial fixation: a case report and literature review

PURPOSE

The objective of this case report is to highlight occipital bone erosion as an unusual late complication of C1-C2 instrumented fixation.

CASE PRESENTATION

A 60-year-old man of a displaced Anderson type II odontoid fracture was surgically treated by C1-C2 pedicle screw fixation. Occipital bone erosions, caused by a repeat irritation of the end of rod to the occipital bone, were detected on multiplane reconstructed computed tomography at 3 months after surgery. The lesion progressed over time with increasing the C2 anteversion on radiological evaluations. Eventually, the bony shell had been reactively formed around the protruded screw-rod construct and the Oc-C1 segment had been spontaneously stabilized. Fortunately, he had experienced no symptoms caused by the lesion at 5-year follow-up.

CONCLUSION

The occipital bone erosion is an unusual late complication in C1-C2 posterior fixation using C1 pedicle screw. The increasing occipital-C1 lordosis compensating for the great C2 anteversion (high C2 slope) was related to the progression of the lesion. In C1-C2 pedicle screw fixation, surgeons should recognize a possibility of this complication and realize a relation between the occurrence of the lesion and the sagittal alignment of the cervical spine to take measures to avoid the complication.

Delayed Vertebral Artery Dissection after Posterior Cervical Fusion with Traumatic Cervical Instability: A Case Report

Vascular injury presented immediately after the penetration, but delayed onset of vascular symptom caused by an embolism or vessel dissection after cervical fusion or traumatic event is extremely rare. We present a case of a 56-year-old woman who underwent an operation for cervical fusion for type II Odontoid process fracture. She presented symptoms of seizure with hemiparesis in 6 days after the operation. Multifocal acute infarction due to an embolism from the left VA (V3 segment) dissection was observed without a definite screw breach the transverse foramen. We hereby reported the instructive case report of delayed onset of vertebral artery dissection after posterior cervical fusion with type II odontoid process fracture patient. When a cervical operation performed in the cervical trauma patient, even if no apparent VA injury occurs before and during the operation, the surgeon must take caution not to risk cerebral infarction because of the delayed VA dissection.