Management of complex cervical instability.

Purpose  Illustrative cases are presented to demonstrate the surgical management of complex instability of the cervical spine. Methods  Six patients with different underlying pathologies are presented along with their clinical and radiologic findings, surgical procedures, complications, and outcomes. Results  Five patients underwent anteroposterior (AP) decompression and stabilization, of which two required secondary posterior stabilization because of dislocation or subsidence of the anterior osteosynthesis. In another case, a patient with a two-level corpectomy, a stable situation was achieved with an anterior approach only. The outcomes, measured according to Odom's criteria, were excellent in one patient, good in three patients, and fair in two patients. Conclusions  In cases of complex cervical instability, combined AP decompression and stabilization minimizes the risk of anterior plate failure or dislocation of the vertebral body prosthesis. However, there may be increased risk of adjacent-level degeneration. Therefore, a combined procedure should be considered in selected patients. Not all patients with cervical instability require circumferential surgery. In two-level corpectomy cases, the decision between the less invasive anterior-only approach and the more stable combined approach can be difficult. However, in patients with proof of poor bone quality or with metabolic disorders, a more stable combined approach should be considered.