Bone marrow aspirate concentrate (BMAC) harvested in the axial and appendicular skeleton does not differ in progenitor cell count: A systematic review and meta-analysis.

Introduction: Bone marrow aspirate concentrate (BMAC) is a reliable source of progenitor cells that facilitate healing, and it is typically harvested from the iliac crest. The purpose of this systematic review and meta-analysis was to compare total nucleated cell (TNC) count and the presence of colony-forming units (CFUs) in BMAC harvested from axial versus appendicular harvest sites. Methods: In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, PubMed, Embase, and Cochrane Library databases were searched in August 2024 for studies published after 2004. Studies were included if they evaluated cell counts within BMAC samples harvested from males and females of any age and were prospective. Studies that had no reported cell count within BMAC samples, had evaluations of biologic material other than BMAC, or were translational or cadaveric studies, as well as review articles or technical notes, were excluded. Patients were divided into two cohorts based on whether BMAC was harvested from their axial or appendicular skeleton. Results: The initial search identified 2126 studies, of which 15 non-randomized prospective studies with a total of 583 patients were included. Each study had low risk of bias. In the axial skeleton, TNC counts ranged from 0.1-502 × 10 Conclusions: BMAC harvested from the axial and appendicular skeletons demonstrate significant variability in progenitor cell concentration. These findings suggest that harvesting at appendicular sites near the operative location allows the surgeon to extract sufficient quality BMAC as compared to harvest sites within the axial skeleton, such as the iliac crest. Level of evidence: Level II, systematic review of level II studies.