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Updated: May 8, 2025

Anterior Cervical Discectomy and Fusion in the Ovine Model
Published on: October 5, 2009
Three-Level Anterior Cervical Discectomy and Fusion With or Without an Investigational Posterior Stabilization System
K Brandon Strenge1, Joshua E Heller2, Daniel M Williams3
1Strenge Spine Center, Paducah, KY.
Study Design:
Prospective randomized controlled trial.
Objective:
This trial was designed to understand safety and effectiveness outcomes in subjects with three-level cervical degenerative disc disease treated with anterior cervical discectomy and fusion (ACDF) alone or supplemented with a posterior cervical fusion (PCF) performed using an investigational posterior cervical stabilization system (PCSS).
Background:
ACDF remains the most common surgical treatment for cervical disc disease. Long-segment (3+ disc levels) procedures are associated with increased risk of complications including symptomatic nonunion. Supplementing ACDF with PCF to form a circumferential cervical fusion (CCF) improves biomechanical stability but increases the surgical burden for the patient.
Materials And Methods:
This multicenter study compared outcomes in participants with three-level symptomatic cervical disc degeneration treated with either ACDF or CCF. The CCF procedure incorporated PCF with PCSS. The primary endpoint was 12-month fusion success, defined by bridging bone across the interbody and range of motion <2° across all treated disc levels. The 24-month secondary endpoint was a composite of fusion success, neck disability index (NDI) improvement, neurological status success, and freedom from surgical revision.
Results:
This protocol-defined interim analysis included 202 participants with 12-month outcomes and 116 participants with 24-month outcomes. Twelve-month fusion success was higher for CCF (61/100, 61%) compared with ACDF (17/102, 17%) ( P <0.001). The 24-month secondary endpoint was also improved with CCF compared with ACDF [51% (30/59) vs. 23% (13/57); P =0.002]. Revision rates were lower for CCF (1/59, 2%) compared with ACDF (13/57, 23%) ( P <0.001), with 11 of 13 ACDF revisions addressing symptomatic nonunion. Adding supplemental PCF with PCSS did not increase the rates of adverse events (ACDF=65%, CCF=46%, P =0.005).
Conclusions:
This study represents the first randomized controlled trial assessing treatment of three-level cervical disc disease. Long-segment ACDF demonstrated low fusion rates and high rates of revision. Adding supplemental PCF with PCSS improved fusion without increasing the risk of surgical complications.

