Comparison of the Fusion Rates between 3D-Printed Porous Titanium Alloy Cage and Titanium-Coated PEEK Cage in Lumber Interbody Fusion

• Published in: Journal of Spine Research Vol. 14; no. 9; pp. 1219 - 1224
• Main Authors: Hatano, Masaru, Maruo, Keishi, Nishio, Shoji, Nakamura, Yoshiteru, Nakamura, Yoshihiro, Tachibana, Toshiya
• Format: Journal Article
• Language: Japanese
• Published: The Japanese Society for Spine Surgery and Related Research 20.09.2023
• Subjects: Bony union; Cage; Lumber interbody fusion
• ISSN: 1884-7137; 2435-1563
• DOI: 10.34371/jspineres.2022-0058

Introduction: Our previous study has demonstrated that polyetheretherketone (PEEK) cages and titanium-coated PEEK (TCP) cages exhibit similar fusion rates at 3 and 12 months. Thus, a three-dimensional (3D)-printed porous titanium alloy (PTA) cage has been introduced as a new interbody cage material. The aim of this study was to compare radiographic outcomes between the TCP and PTA cages.Methods: A total of 97 patients, who underwent 1- or 2- level transforaminal lumbar interbody fusion between October 2015 and July 2020, were enrolled. A total of 97 cases (TCP: 37 cases and PTA: 60 cases) and 121 levels (TCP: 50 levels and PTA: 71 levels) were studied. Patient and surgical factors included age, sex, number of levels, operative time, and estimated blood loss. Moreover, radiographic outcomes including endplate cyst, pedicle screw (PS) loosening, cage subsidence (>2 mm), and trabecular bone remodeling (TBR) were assessed by computed tomography (CT) at 3 months after surgery. Bony union was assessed by CT at 12 months after surgery.Results: There was no significant difference observed in patients and surgical factors between the two groups. Furthermore, positive cyst sign was significantly less in the PTA group than in the TCP group (30% vs. 54%, p = 0.01). The TBR was significantly more in the PTA group than in the TCP group (52% vs. 72%, p = 0.03). The fusion rate was equivalent between the two groups at 12-months postoperatively (TCP: 86% vs. PTA: 87.3%, p = 0.83). The incidence of PS loosening was also similar between the two groups.Conclusions: This study revealed that the fusion rate was similar between the two groups at 12 months. However, endplate cyst signs were significantly less in the PTA group and TBR was significantly more in the PTA group at 3 months after surgery. These results suggest that the PTA cages may have an advantage due to the initial fixation strength.