Outcomes of 2-Level Versus 3- or 4-Level Anterior Cervical Discectomy and Fusion Using a Biomimetic Surface Titanium Cage: Multicenter Experience

Objective: Interbody cages for spinal fusions are primarily constructed from polyetheretherketone or titanium compositions. However, these crude macroscopic materials pose limitations for improving the rates of bony fusions. The authors aimed to compare the fusion rates and postoperative complications in patients who underwent 2-level or 3-or 4-level anterior cervical discectomy and fusion (ACDF) performed with the use of a novel biomimetic surface titanium cage. Methods: A retrospective multicenter study was conducted that included all patients who underwent multilevel ACDF with this cage between January 2017 and April 2021. Patient demographics and procedure-related, radiographic, and postoperative complication data were collected. Results: A total of 124 patients were identified; 69 (55.6%) had a 3-or 4-level fusion and 55 (44.4%) had a 2-level fusion. The demographics of the 2 groups differed significantly only in terms of age (P = 0.01). At 3 months, a significantly higher solid fusion rate was found for 2-level fusions than 3-or 4-level fusions (83.7% vs. 56.3%, P = 0.004); however, significance was lost at 6-months (98.2% vs. 88.4%, respectively; P = 0.08). No patients required posterior supplemental fixation. Transient dysphagia was the only postoperative complication that was significantly increased in the 3-or 4-level fusion group compared to the 2-level group (27.5% vs. 9.1%, P = 0.02). Conclusions: Radiographic and clinical outcomes were equivalent in 3-or 4-level and 2-level ACDFs in which these biomimetic surface titanium cages were used. Furthermore, the use of this technology led to high fusion rates with no requirement for posterior supplemental fusions.