Evaluation of 3d-printed Porous Titanium Alloy versus Polyetheretherketone (PEEK) Cages in the Surgical Treatment of Multilevel Cervical Degenerative Disease

Introduction: Anterior cervical discectomy and fusion (ACDF) with 3D-printed titanium (3D-TTN) or polyetheretherketone (PEEK) cages is an effective surgical approach for treating cervical radiculopathy and myelopathy. However, there is a paucity of literature examining level-specific analysis and long-term outcomes of 3D-TTN and PEEK cages in multilevel ACDF procedures. This study aims to compare the 2-year postoperative clinical and radiographic outcomes of PEEK and 3D-TTN implants, focusing on level-specific outcomes.

Methods: A single-center retrospective study was conducted on patients with multilevel cervical radiculopathy and/or myelopathy treated with ACDF. Radiographic outcomes, including level-specific fusion, cage migration, and subsidence, were assessed using flexion-extension cervical x-rays. Fusion was defined as less than 2 mm of spinous process motion. Statistical analyses included the two-sample t-test and χ² test. Clinical outcomes were evaluated using the Visual Analog Scale (VAS) and Neck Disability Index (NDI), with repeated measures analysis of variance for statistical assessment.

Results: A total of 96 patients met the inclusion criteria, with 69% in the PEEK group and 31% in the 3D-TTN group. At the 1-year postoperative visit, the 3D-TTN group had a significantly lower NDI score (6.74 ± 5.58 vs. 11.29 ± 8.67, p = 0.017). Additionally, the 3D-TTN group exhibited a significantly shorter time to fusion at the distal levels in 3-level procedures. Pseudoarthrosis occurred more frequently distally at C6-C7 and C5-C6. No reoperations were required.

Conclusion : 3D-TTN cages demonstrated a shorter time to bony fusion at distal levels during 3-level procedures and improved NDI scores at 1 year postoperatively compared to PEEK cages. These findings suggest that 3D-TTN implants may improve both clinical and radiographic outcomes for patients undergoing multilevel ACDF, highlighting important differences between PEEK and 3D-TTN cages that should be considered when selecting the most optimal implant for these procedures.