BackgroundThe differences in clinical and radiographic outcomes between 3-dimensional computer navigation (NAV) and fluoroscopic-guided (FLUO) minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) are currently unclear, with different studies showing different advantages of each technique. This study aimed to compare the clinical and radiographic outcomes of NAV and FLUO MIS-TLIF. Furthermore, we determined the correlation between radiographic findings and predictable clinical outcomes.

Methods:

Between January 2016 and October 2018, 97 consecutive patients who had undergone MIS-TLIF with the lumbosacral degenerative disease in our institute were retrospectively reviewed. Radiographic outcomes (angle of screw convergence, screw-to-pedicle diameter ratio, %screw depth, screw penetration, %fusion, and facet joint violation) were analyzed by 2 independent orthopedists using thin-slice computed tomography. Clinical outcomes were assessed with Oswestry Disability Index (ODI), visual analog scale (VAS), and satisfaction score. The association between radiographic and clinical outcomes was then analyzed to determine the predictable variable outcomes.

Results:

Sixty-one patients (270 screws) in the FLUO group and 36 patients (172 screws) in the NAV group were compared. The NAV group showed a significantly higher %screw depth (89.04% ± 6.07% vs 85.18% ± 7.54%; P = 0.011), larger angle of screw convergence (27.7° ± 3.93° vs 18.44° ± 7.54°; P < 0.001), lower incidence of pedicle penetration (0% vs 3.7%; P = 0.016), and less facet joint violation (1.0% vs 8.1%; P = 0.003). The clinical results revealed a significantly better VAS and ODI in the NAV group at 6 and 12 months. The %screw depth correlated with the VAS back pain score at the 1-year follow-up.

Conclusions:

NAV MIS-TLIF showed superior screw placement accuracy, better screw convergence and depth, and lower cranial facet joint violation than FLUO MIS-TLIF. Furthermore, better clinical scores were revealed in the NAV group at the 6-month and 1-year follow-up.

Level of evidence:

3.