Comparison of Clinical and Radiological Outcomes of Oblique Lateral Interbody Fusion With and Without rhBMP-2 at 1 Year Postoperatively

Study Design: Retrospective case series.Objectives: This study aimed to compare fusion rates and clinical outcomes in patients undergoing oblique lateral interbody fusion (OLIF) with and without the use of Escherichia coli-derived recombinant human bone morphogenetic protein-2 (rhBMP-2), and to evaluate the association between fusion status and clinical outcomes.Summary of Literature Review: rhBMP-2 has been widely studied in lumbar interbody fusion because of its strong osteoinductive properties.However, comparative data specific to OLIF (with vs without rhBMP-2) remain limited, and the optimal dosing strategy has not been clearly established.Furthermore, fusion rates do not consistently correspond to patient-reported outcomes, such as pain and quality of life, and studies examining these relationships in OLIF are scarce.Although computed tomography (CT) is considered the standard modality for assessing bony bridging, its association with clinical outcomes in OLIF has not been clearly established.Materials and Methods: This retrospective study was conducted at a single tertiary center and included patients who underwent oneor two-level OLIF.Fusion (interbody and facet) and segmental stabilization were assessed using 1-year postoperative CT and flexionextension dynamic radiographs.Clinical outcomes, including the visual analog scale (VAS) for low back pain, VAS for radiating pain, Oswestry Disability Index (ODI), and EuroQol-5 Dimensions (EQ-5D), were evaluated preoperatively and at 1 year postoperatively.Results: A total of 66 patients with 88 fusion levels were included in the study.Regarding interbody graft materials, demineralized bone matrix (DBM) alone was used in 70 levels, whereas DBM combined with rhBMP-2 was used in 18 levels.Radiologic assessment at the 1-year follow-up demonstrated complete bony fusion in 50 of 88 levels (55.1%) on CT and stabilization in 82 of 88 levels (93.2%) on dynamic radiographs.Although the overall fusion rate was higher in the rhBMP-2 group (72.2% vs 52.9%), this difference was not statistically significant.However, interbody fusion rates were significantly higher in the rhBMP-2 group (61.1% vs 25.7%, p=0.004).No significant differences in clinical outcomes were observed between the two groups at the 1-year follow-up.However, improvement in EQ-5D scores was significantly greater in the stabilized group than in the non-stabilized group (3.0 vs 1.4, p=0.04).Conclusions: In patients undergoing OLIF, the use of rhBMP-2 was associated with higher interbody fusion rates at 1 year