Impact of Navigation Modality on Radiographic Parameters Following Minimally Invasive Transforaminal Lumbar Interbody Fusion

Study Design Single-center, retrospective cohort review. Objective This study aims to compare the impact of robotic and imaging-only navigation modalities on radiographic parameters following minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). Methods Patients with degenerative spondylolisthesis who underwent one-level MI-TLIF using navigation or robotic modalities were included and divided into two groups: robotic-assisted (Robo) or imaging-only navigation (Nav). Radiographic parameters were assessed preoperatively and 6 months postoperatively. Outcome measures were screw and cage characteristics, postoperative disc height (DH) improvements, lumbar lordosis (LL), and slip reduction rates. Statistical analyses included paired and independent samples t-tests and multivariable linear regression analysis. Results The Robo group often used larger screw diameters, deeper cages, and more expandable cages, while the Nav group used wider cages. The Robo group demonstrated significantly greater DH improvement compared to the Nav group (average improvement: 71.6% vs 22.5%, P = 0.002). However, the Nav group showed significantly greater LL restoration than the Robo group ( P = 0.006), and preoperative LL was independently associated with postoperative LL (β = 0.64, P < 0.001). No clear differences in slip reduction or cage subsidence were observed. Conclusions In MI-TLIF, robotic guidance was associated with greater DH restoration and the use of larger screws, whereas LL restoration appeared to depend mainly on preoperative sagittal alignment and was greater with image-guided navigation. These findings suggest that each modality can be leveraged to optimize different radiographic goals and underscore the need for studies integrating implant strategies with clinical outcomes.