Bone Morphogenetic Protein in Anterior Lumbar Interbody Fusions: A Propensity-Matched Medicare Outcome Analysis

Bone morphogenetic protein (BMP) is a costly agent commonly used in spine surgery. Its effectiveness and complication profile have never been studied in a large, propensity-matched population following its approval by the Food and Drug Administration for use in single-level anterior lumbar interbody fusion (ALIF) surgeries.

To investigate the rate of symptomatic pseudarthrosis or need for revision surgery after single-level stand-alone ALIFs with and without the use of BMP.

Medicare Standard Analytic files derived from Medicare parts A and B were used to identify adult patients who underwent single-level ALIF procedures with and without use of BMP between 2004 and 2014. Patients were propensity matched based on their age, gender, and history of diabetes mellitus, hypertension, chronic kidney disease, body mass index greater than 30 kg/m², smoking, rheumatoid arthritis, and osteoporosis. Sensitivity analysis using adjusted multivariate logistic regression models was also performed. The primary outcomes were the rates of symptomatic pseudarthrosis or need for revision surgery.

The propensity-matched population analyzed in this study contained 22,380 patients undergoing single-level ALIF (8971 [40.6%] with BMP and 13,139 [59.4%] without BMP). Both patient groups were balanced at baseline. The rate of symptomatic pseudarthrosis in the propensity-matched analysis was higher in the BMP group (1.9% vs 1.4%, P < 0.05). BMP use during single-level ALIFs was associated with 44% increased odds of developing pseudarthrosis (OR 1.44, 95% CI 1.16-1.76). However, there was no statistically significant difference in the rate of revision surgery between groups (3.7% vs 3.5%, P = 0.49).

BMP use in single-level ALIFs may be associated with increased risk of symptomatic pseudarthrosis. Large prospective pragmatic trials are needed to corroborate our findings.