Evaluation of 3D-printed Porous titanium alloy versus Polyetheretherketone (PEEK) cages in the surgical treatment of multilevel cervical degenerative disease

Study Design - Single-center retrospective cohort study. Purpose - To compare the long-term clinical and radiographic outcomes of patients who have undergone multilevel anterior cervical discectomy and fusion (ACDF) with either 3D-printed titanium (TTN) or polyetheretherketone (PEEK) cages. Overview of Literature - ACDF with 3D-printed TTN or polyetheretherketone (PEEK) cages is an effective surgery for patients with cervical radiculopathy/myelopathy. The advent of 3D-printed porous TTN cages and its microporous structure has contributed to diminished subsidence and improved osseointegration compared to PEEK. This study compares the long-term outcomes of both implants among patients who underwent a multi-level ACDF procedure. Methods – 96 patients underwent multilevel (2, 3, 4) ACDF surgery, of whom 66 and 30 received a PEEK and 3D-printed TTN interbody cage, respectively. Radiographic outcomes for fusion, cage migration, and subsidence were determined with cervical x-rays and analyzed with independent 2-sample T-test and χ2 test. Visual analog score (VAS) and Neck Disability Index (NDI) score were examined with repeated measure analysis of variance. Results - The TTN group reported diminished NDI scores compared to the PEEK group (6.74 ± 5.58 vs 11.29 ± 8.67, p = 0.017) 2 years postoperatively. Furthermore, patients with 3D-printed TTN implants had a significantly shorter duration to fusion at the distal operated level in 3-level ACDF procedures (12.0 ± 5.20 vs 19.1 ± 5.91) (p = .011). The two cohorts reported no statistically significant difference in fusion rates. Conclusions – 3D-printed TTN implants enhanced the time to bony fusion at distal levels relative to PEEK cages. Clinically, patients with 3D-printed TTN implants reported diminished NDI scores at 2 years postoperatively. Such findings highlight the difference in outcomes clinically and radiographically for PEEK and 3D-printed TTN implants that need to be considered in optimizing multilevel ACDF procedures.