Comparative Analysis of Different Needle Techniques for Bone Marrow Harvest

Background: Biologic therapies, including the use of autologous bone marrow-based preparations, have demonstrated promise for the treatment of painful musculoskeletal pathologies. Historically, the primary therapeutic cell of interest within bone for musculoskeletal applications is the Mesenchymal Signaling Cell (MSC). As interest in these treatments has increased, further study of harvest techniques and laboratory quantification of aspirates is needed. The aim of this pilot study was to quantify and Compare Total Nucleated Cell Counts (TNCs), MSCs (as measured by fibroblast colony-forming units, CFU-fs), and CD34+ cells in small-volume aspirates using two different commercially available bone marrow harvesting needles in the same patient. Methods: Twenty-nine patients undergoing elective bone-marrow-based procedures had a bone marrow aspiration of 5 cc using a single port 11-gauge bone marrow biopsy needle (SP side) on one posterior superior iliac crest (PSIS) and another 5 cc aspiration on the contralateral side using a multi-port 11 gauge bone marrow biopsy (MP side). Small samples from these aspirations were sent to an independent lab for TNC, CFU, and CD34+ cell comparative analysis. Wilcoxon matched-pairs signed rank tests were used for comparison of differences between groups. Results: Of the 29 patients included in this pilot study, 7 patients were female and 22 were male and the mean age of the patients was 57.9 years with a range from 24 to 81 years. Mean age was 57.9 years (range 24 to 81 years). The mean TNC count for the MP side, 46.4 x 106 ± 4.6 x 106 per mL, was significantly higher (p < 0.001) than the mean TNC count for the SP side, 33.8 x 106 ± 4.51 x 106 per mL. In addition, the mean CFU-f count for the MP side, 4469 ± 583 per mL, was significantly higher (p < 0.0001) than the mean CFU-f count for the SP side, 2676 ± 626 per mL. Of the 29 patients studied, 23 (79.3%) had higher CFU-f levels in the MP aspirate as compared with the SP aspirate. CFU-fs for both the SP and MP sides demonstrated a strong correlation with TNC, with Spearman’s Correlation Coefficient of 0.718 and 0.749, respectively. The levels of CD34+ cells were analyzed in 21 of the 29 patients and no significant difference (p = 0.1193) was seen between the two aspiration techniques. Conclusions: In this pilot study, two thirds of patients had a substantially higher CFU-fs/mL yield from a MP aspiration when compared to the SP side. This suggests that using a multiport bone marrow biopsy needle may provide an increased yield of MSCs present within an initial, small volume, 5 cc bone marrow aspiration from the PSIS when compared with a SP low volume aspiration. This could have clinical implications for targets requiring only a small volume of bone marrow for treatment and may eliminate the need for concentration of aspirate for these applications, thereby potentially decreasing procedural time and risk of contamination. In addition, the mean CFU-f/mL levels of both aspirates were higher than previously reported minimal CFU-f/mL levels associated for clinical efficacy in prior studies. Further study is needed to validate these findings and determine clinical significance. Keywords: Bone Marrow Aspirates (BMAs), Orthobiologics, Regenerative, Harvest