Anterior Cervical Discectomy And Fusion (ACDF): Comparison Between Zero Profile Implants And Anterior Cervical Plate And Spacer

Presented at SMISS Annual Forum 2014
By Marjan Alimi MD
With Christoph P. Hofstetter MD, PhD, Roger Haortl MD, Apostolos J. Tsiouris MD, Innocent Njoku BS, Kartik Kesavabhotla MD, John Boockvar MD,

Disclosures: Marjan Alimi MD None. Christoph Hofstetter MD, PhD , Roger Haortl MD B; Brainlab, DePuy-Synthes, Ulrich, Apostolos Tsiouris MD None, Innocent Njoku BS None, Kartik Kesavabhotla MD None, John Boockvar MD None,

Introduction:
Interposition grafts combined with anterior plating currently remain the gold standard for anterior cervical discetomy and fusion. The use of anterior plates increases fusion rates, but may be associated with higher rates of postoperative dysphagia.

Aims/Objectives:
To determine the clinical and radiological outcomes following anterior cervical discectomy and fusion (ACDF) using zero-profile anchored spacers versus standard interposition grafts with anterior plating.

Methods:
This was a retrospective cohort of 104 patients. A total of 53 male and 51 female consecutive patients (164 total operated levels) who underwent ACDF between 2007 and 2011 were included. The mean clinical follow-up was 15.7 ± 1.2 (SEM) months for patient with zero-profile implants and 14.8 ± 2.1 months for patients with conventional ACDF with anterior plating. Patient demographics, operative details, clinical outcome, complications and radiographic imaging were reviewed. Dysphagia was determined using Bazaz criteria.

Results:
Clinical outcome scores were similar between both groups as measured by the modified JOA and Nurick scores. Zero-profile constructs gave rise to significantly less prevertebral soft tissue swelling compared to constructs with anterior plates postoperatively (15.74 ± 0.52 as compared to 20.48 ± 0.85 mm, p < 0.001) and at the lastest follow-up (10.88 ± 0.39 mm vs. 13.72 ± 0.67 mm, p < 0.001). There was a significant difference in the incidence of dysphagia at latest follow-up between cohorts (1.5% vs. 20%, p=0.001, zero-profile vs. anterior plate respectively).

Conclusions:
Zero-profile implants lead to functional outcomes similar to standard anterior plate constructs. Absence of an anterior locking plate may decrease the risk of postoperative dysphagia. Further studies are required to delineate the pathophysiological mechanisms underlying postoperative dysphagia after ACDF.