Comparison of Zero-profile Anchored Spacer Versus Plate-and-Cage After 1-Level ACDF With Complete Uncinate Process Resection : A 3-Year Assessment of Radiographic and Clinical Outcomes

Abstract

Study Design: This is a retrospective study.

Objective: The purpose of this study is to compare the zero-profile anchored spacer device (Zero-p) and traditional plate-and-cage implant (plate-and-cage) in anterior cervical discectomy and fusion (ACDF) with complete uncinate process resection (UPR) to treat 1-level cervical degenerative disk disease.

Summary of Background Data: We retrospectively surveyed the data from all patients who underwent single-level ACDF with complete UPR between 2009 and 2013.

Patients and Methods: In total, 80 patients participated in 3 years of follow-up. Among them, Zero-p (38 patients) and plate-and-cage (42 patients) approaches were used in ACDF with complete UPR. Clinical outcomes and radiographic results were compared between 2 groups and they were followed for 39.1±2.2 months.

Results: Duration of operation, intraoperative blood loss, and length of hospitalization were significantly lower in the Zero-p group than the plate-and-cage group (P<0.001). The clinical outcomes of visual analog scale, neck disability index, and the Odom criteria were improved after operation in both groups. The fusion rates, C2–C7 lordosis, T1 slope, C2–C7 sagittal vertical axis, sellar turcica–C7 sagittal vertical axis, and spinocranial angle after single-level ACDF were not significantly different between the 2 groups. Subsidence occurred in 5 cases (13%) in the Zero-p group and 10 cases (37%) in the plate-and-cage group (P<0.05). The horizontal length of the Zero-p implant was longer than that of allograft bone. Fusion occurred in 37 cases (95%) of the Zero-p group and 40 cases (94%) in the plate-and-cage group.

Conclusions: The Zero-p and plate-and-cage are effective when single-level ACDF with complete UPR was performed. Both groups showed good clinical outcomes, but Zero-p has more benefits than plate-and-cage such as lower duration of operation, intraoperative blood loss, length of hospitalization, and rate of subsidence compared with plate-and-cage. Surgeons should be aware of these results so that postoperative complications such as subsidence can be avoided.