Lumbar Fusion With Micro- & Nano-Textured, 3D Printed Porous Titanium Versus PEEK Interbody Cages in TLIF: A Single-Blinded, Randomized Controlled Trial

Study Design Prospective, randomized controlled study. Objective Assess early radiological outcomes in transforaminal lumbar interbody fusion (TLIF) with 3D-printed porous titanium (3DPPT) compared to PEEK. Methods Single-blinded prospective, randomized controlled trial comparing 1-2 level TLIF with micro- & nano-textured, 3DPPT vs PEEK cages from 11/2021 to 5/2023. Interbody fusion was assessed on CT at 6 months according to Brantigan and Steffee method, modified to describe the Fraser definition of locked pseudoarthrosis [(BSF) scale]. Primary outcome was radiographic fusion at 6 months. Results Initial study protocol included 70 total patients but was ended early given the significance on interim analysis. Amongst 17 patients with 25 interbody levels implanted, 10 3DPPT and 15 PEEK cages were implanted. 3DPPT levels had a significantly higher rate of successful fusion (BSF-3) at 6 months compared with PEEK (100% vs 0.0%, P < 0.001). The posterior probability that 3DPPT increased the odds of fusion versus PEEK was > 99.9%, indicating a near-certain beneficial effect. Using a Bayesian mixed-effects model, the predicted probability of 6-month BSF-3 fusion was 9.0% for PEEK and 91.2% for 3DPPT. There were no significant differences in lumbar pathologies, level of fusion, number of fused levels, cage height, length of hospital stay, surgery duration, postoperative complications, subsidence, or reoperations. Conclusions The rate of successful lumbar interbody fusion at 6 months was significantly higher in 3DPPT levels compared to PEEK. 3DPPT may accelerate the rate and quality of bony fusion. Additional studies are needed to further delineate the impact of these radiographical findings on long-term clinical outcomes.