Lytle EJ, Lawless MH, Paik G, et al. - A systematic review and meta-analysis were conducted to ascertain the minimally effective dose (MED) of bone morphogenetic protein-2 (BMP) which results in optimal fusion rates while minimizing complications; to determine the impacts of the location of BMP placement has on fusion rates and complications. Researchers applied PubMed, Embase, and Cochrane Database to distinguish studies published between 1/1/2011-8/1/2019 reporting BMP usage in adult patients who had undergone posterior lumbar interbody fusion/transforaminal lumbar interbody fusion degenerative indications. Performing a qualitative and quantitative synthesis, the minimally effective dose of BMP and the effect of location of BMP placement on fusion and complications were analyzed. This study included 22 articles, involving a total of 2,729 patients. There was no significant difference of fusion and complication rates between different doses of BMP with the lowest MED for fusion as low as 1.28 mg/level. Fusion or complication rates were not significantly influenced by the location of BMP placement.