RESUMEN
PURPOSE: The purpose of this study was to analyze the clinical and radiological outcomes of two different zero-profile spacers (ROI-C and anchor-C) in contiguous two-level ACDF for CDDD patients. METHODS: We retrospectively analyzed patients who underwent contiguous two-level ACDF due to CDDD between January 2015 and December 2020 in our hospital. Patients who received ROI-C and anchor-C were included as the study groups, and those who underwent plate-cage construct (PCC) were included as the control group. The primary outcome measures were radiographical parameters, and the secondary outcome measures were dysphagia, JOA scores and VAS scores for these patients. RESULTS: A total of 91 patients were enrolled in the study; there were 31, 21 and 39 patients in the ROI-C, anchor-C and PCC groups, respectively. The mean follow-up duration was 24.52 months (range, 18-48 months) in the ROI-C group, 24.38 months (range, 16-52 months) in the anchor-C group and 25.18 months (range, 15-54 months) in the PCC group. The loss of the intervertebral space height and cage subsidence rate in the ROI-C group were significantly higher than those in the anchor-C group and PCC group at the final follow-up (P < 0.05). The ROI-C group showed a lower incidence of adjacent segment degeneration than the anchor-C group and PCC group, but the difference was not significant. The fusion rates were not different among these three groups. The early dysphagia rate was significantly lower in the patients with zero-profile spacers than in the PCC group (P < 0.05), but the difference was not significant at the last follow-up. No relevant differences were found in the JOA scores and VAS scores. CONCLUSIONS: Zero-profile spacers showed promising clinical outcomes in CDDD patients having contiguous two-level ACDF. However, ROI-C resulted in a higher intervertebral space height loss and a higher cage subsidence rate than anchor-C during the follow-up.