Does a zero-profile anchored cage offer additional stabilization as anterior cervical plate?

Abstract

Study design: Retrospective cohort study.

Objective: This study aimed to compare 3 different surgical methods of single-level anterior cervical interbody fusion consisting of stand-alone cages (SCs), cages with plates (CPs), and anchored cages (ACs) (zero-profile). It focused on postoperative retention and motion stabilization.

Summary of background data: Several authors reported the radiological and clinical results of ACs, which seem similar to plates. However, it remains unclear whether ACs offer additional stabilization like plates.

Methods: Between 2005 and 2011, SCs (n=60) and CPs (n=18) were used to surgically treat patients with single-level cervical degenerative diseases. From January 2012 to June 2013, ACs were used (n=23). We compared retention (cervical alignment, segmental angle, and segmental height) and motion stabilization (change of segmental angle and distance of interspinous process in flexion/extension). We also investigated subsidence, fusion rates, and clinical outcomes. The mean follow-up period was 19.9 months.

Results: The CP and AC groups showed significantly more retention at 12 months after surgery than the SC group (P<0.05). The CP group had significantly greater motion stabilization than the SC group (P<0.05). However, there was no statistically significant difference between the AC and SC groups. The subsidence rates of the SC, AC, and CP groups were 40.0%, 21.7%, and 11.1%, whereas the fusion rates were 83.3%, 87.0%, and 100.0%, respectively. Arm and neck visual analogue scale scores and Odom criteria showed superior results in the CP and AC groups than in the SC group (P<0.05).

Conclusion: The AC displayed similar retention and clinical outcomes to those of the CP. However, the AC was inferior to the CP in motion stabilization, subsidence prevention, and fusion rate. Therefore, for patients who require strong postoperative motion stabilization, CPs rather than ACs should be used.

Level of evidence: 4.