Gene-Activated Octacalcium Phosphate (OCP/VEGF) Versus Autologous Bone Graft for Single-Level TLIF in Degenerative Lumbar Stenosis

Background: Autologous bone graft is widely used for lumbar interbody fusion but may increase operative time and donor-site morbidity. Gene-activated grafts combining an osteoconductive scaffold with pro-angiogenic signaling may provide comparable fusion without graft harvesting. The aim of this paper is to compare radiographic fusion and health-related quality of life after single-level transforaminal lumbar interbody fusion (TLIF) using a gene-activated octacalcium phosphate graft containing plasmid DNA encoding vascular endothelial growth factor (OCP/VEGF) versus an autologous bone graft. Methods: 200 adults undergoing first-time single-level TLIF for degenerative lumbar stenosis were allocated 1:1 to OCP/VEGF (n = 100) or autograft (n = 100), prospectively. CT-based fusion assessment and SF-36 outcomes were evaluated at 6 and 12 months follow-up. Results: At 12 months after surgery, mean fusion-zone density was 617.6 ± 180.9 HU in the OCP/VEGF group versus 599.8 ± 181.9 HU in the autograft group (mean difference 17.8 HU; p = 0.484). Complete fusion on qualitative CT grading occurred in 77% versus 73%, respectively (risk difference 4%; p = 0.583). SF-36 Physical Component Summary (PCS) and Mental Component Summary (MCS) improved significantly from baseline in both groups (p < 0.001), without clinically meaningful between-group differences at follow-up. Revision surgery occurred in 3% versus 5%. Conclusions: In single-level TLIF for degenerative lumbar stenosis, OCP/VEGF produced radiographic fusion and patient-reported outcomes comparable to autograft at 12 months, supporting its use as an autograft-sparing alternative.