Single-Level Anterior Cervical Discectomy and Interbody Fusion: A Comparison between Porous Tantalum and Polyetheretherketone Cages

Background: Anterior cervical discectomy and interbody fusion (ACDF) may be performed with different kinds of stand-alone cages. Tantalum and polyetheretherketone (PEEK) are two of the most commonly used materials in this procedure. Few comparisons between different stand-alone implants for ACDF have been reported in the literature. Methods: We performed a comparison between patients who underwent ACDF with either a porous tantalum or a PEEK stand-alone cage, in two spine surgery units for single-level disc herniation. Clinical outcome [Neck Disability Index (NDI), Visual Analog Scale (VAS) for pain, Short Form-36 (SF-36)] and radiological outcome (lordosis, fusion and subsidence) were measured before surgery and at least one year after surgery in both groups. Results: Thirty-eight patients underwent ACDF with a porous tantalum cage, and thirty-one with a PEEK cage. The improvement of NDI and SF-36 was significantly superior in the PEEK group (p = 0.002 and p = 0.049 respectively). Moreover, the variation of the Cobb angle for the cervical spine was significantly higher in the PEEK group (p < 0.001). Conclusions: In a retrospective analysis of two groups of patients with at least one year of follow-up, a stand-alone PEEK cage showed superior clinical results, with improved cervical lordosis, compared to a stand-alone porous tantalum cage. Further studies are needed to confirm these data.