Can Zero-Profile Cage Maintain the Cervical Curvature Similar to Plate-Cage Construct for Single-Level Anterior Cervical Diskectomy and Fusion?

OBJECTIVE: We sought to compare the clinical and radiologic outcomes after anterior cervical surgery between zero-profile (Zero-P) cage and plate-cage construct (PCC). METHODS: One-hundred and sixteen patients with single-level cervical disk herniation who underwent anterior cervical diskectomy and fusion between May 2015 and March 2017 were enrolled. They were divided into a Zero-P group (61 cases) and a PCC group (55 cases). At 1, 6,12, and 24 months after the operation, routine follow-up evaluation was recommended including visual analog scale score and Japanese Orthopaedic Association score. The lateral x-ray film was performed at 1 and 24 months postoperatively. RESULTS: All 116 patients successfully completed the operation and achieved bone fusion. While there was no significant difference in the amount of bleeding between the 2 groups, the operation time of the Zero-P group was significantly shorter than that of the PCC group with statistically difference. The visual analog scale score and Japanese Orthopaedic Association score of the 2 groups at each follow-up interval postoperatively were significantly improved compared with that before operation; the difference was statistically significant (P < 0.05, respectively). While all the C2-7 cervical curvature, segmental Cobb angle, and height of adjacent vertebral body were lost at the 24-month follow-up, the significant difference was observed in the Zero-P group (P < 0.05, respectively). CONCLUSIONS: Compared with the Zero-P system, the PCC system provides a comparable clinical outcome. Although it showed the disadvantages in controlling the operation time and surgical bleeding, the radiologic outcome was better at the 2-year follow-up.