Stand-Alone Lateral Lumbar Interbody Fusion at L3-L4 with 3D-Printed Porous Titanium Cages: A Safe and Effective Alternative in the Treatment of Degenerative Disc Disease (DDD).

Stand-alone lateral lumbar interbody fusion (LLIF) remains a debated approach in spinal surgery, with limited published evidence supporting its efficacy without supplemental fixation. This prospective study presents the institutional case series on single-level L3-L4 stand-alone LLIF, using next-generation 3D-printed titanium cages, as treatment for degenerative disc disease (DDD). A cohort of 49 patients with symptomatic DDD, unresponsive to conservative therapy, underwent stand-alone LLIF at L3-L4 (neither posterior pedicle screws nor lateral plating). Clinical outcomes (VAS and ODI) and radiological parameters (disc height, segmental/lumbar lordosis) were collected preoperatively and at 1, 6, and 12 months. Repeated-measures ANOVA with Bonferroni correction was adopted for statistical analysis. Significant improvements were observed in pain and disability scores at all time points, with the mean VAS score decreasing from 6.53 to 0.29, and ODI from 27.6% to 3.84% at one year ( < 0.001). Radiographic analysis confirmed durable increases in disc height and segmental lordosis. Solid fusion was achieved in 97.9% of cases. No patient required posterior revision; transient neurological symptoms were mild and self-limiting. This study demonstrates that stand-alone LLIF at L3-L4 is safe and effective in achieving stable fusion and clinical-radiological improvement. These results challenge the necessity of supplemental fixation and support the broader adoption of a less invasive fusion paradigm.