<![CDATA[Lumbar spinal fusion (LSF) is widely used for degenerative lumbar disorders, but pseudarthrosis remains a clinically relevant complication. Bone marrow–based augmentation has been proposed to enhance fusion while reducing reliance on conventional grafting. However, its comparative efficacy and safety remain uncertain. To evaluate the effects of bone marrow–based augmentation on radiographic fusion, clinical outcomes, perioperative outcomes, and safety following LSF. This systematic review followed PRISMA guidelines. PubMed/MEDLINE, Embase, Scopus, Web of Science, and Cochrane CENTRAL were searched without publication-year restrictions for randomized controlled trials (RCTs) evaluating bone marrow aspirate, bone marrow concentrate, or bone marrow-derived mesenchymal stromal cells in adults undergoing lumbar spinal fusion for degenerative lumbar disorders. Of 366 records identified, seven RCTs published between 2008 and 2023, involving 367 participants, met the eligibility criteria. Data on radiographic fusion, clinical and functional outcomes, perioperative outcomes, and safety were extracted and synthesized narratively because of substantial clinical and methodological heterogeneity. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool. Seven RCTs involving 367 participants demonstrated heterogeneous effects on radiographic fusion. Higher fusion rates were observed with selected constructs, including bone marrow-derived mesenchymal stromal cells plus allograft, bone marrow concentrate plus allograft, and bone marrow aspirate plus local bone and hydroxyapatite, whereas other studies showed no significant benefit or lower fusion rates with specific graft combinations. Clinical outcomes generally improved in both groups without consistent between-group differences. Perioperative outcomes and reported safety events were broadly comparable, although safety reporting was inconsistent. Four studies had some concerns, and three had a high overall risk of bias. Bone marrow–based augmentation showed variable effects on fusion, with benefits observed only in selected graft constructs. Current evidence does not establish consistent superiority over conventional grafting for LSF.]]>
