The C7 pedicle as a superior fixation point in spinal stabilization for spinal metastatic disease
Spinal metastatic disease (SMD) often requires spinal stabilization; however, the cervicothoracic junction can be a challenging area to instrument. An anterior approach may require division of the sternum. A posterior or posterolateral approach may rely on cervical lateral mass screws for superior construct fixation that are more prone to pullout than screws placed in a pedicle. The C7 pedicle is able to support pedicle screw fixation in most instances based on morphological features of the vertebra. When the C7 pedicle is used as a superior fixation point, it aligns with the thoracic pedicles below to create a streamlined posterior construct. In this study, patients undergoing posterior stabilization with C7 pedicle superior fixation were examined. One hundred and thirty-nine consecutive spinal operations at a National Cancer Institute designated cancer center were retrospectively reviewed to identify patients who underwent spinal stabilization for SMD with a C7 pedicle screw placed as the superior fixation point of a posterior construct. Patient age, the primary disease, and clinical and radiographic information were identified. Follow-up duration was noted, and follow-up outcomes were recorded on the basis of the clinical history and the findings on computed tomography (CT) spinal imaging. Three patients were identified who underwent separation surgery for SMD that included posterior spinal stabilization with C7 pedicle screws as the superior fixation point. The average patient age was 70 years and one patient was a woman. The average follow-up time was 20.7 months. There were no occurrences of hardware failure, neurologic deterioration, or protracted pain in the cases analyzed. Overall, there were good surgical outcomes with improvement in pain without neurovascular injury or evidence of hardware failure during follow-up evaluation. These findings add to a small but notable number of studies showing the effectiveness of C7 pedicle screws as a superior fixation point in spinal oncology, specifically in metastatic lesions. In our experience the C7 pedicle has provided a useful superior fixation point solution for the posterior stabilization of high thoracic vertebral body metastases. This surgical option may help spinal surgeons address the stabilization of SMD in the cervicothoracic region.