Abstract
BACKGROUND: Bone marrow concentrate (BMC) is growing in popularity as an alternative treatment option in orthopaedics. The regenerative capacity of BMC has been linked to the number of mesenchymal stem cells (MSCs) present in the graft at the time of its clinical application. MSC counts in bone marrow aspirate (BMA) are affected by harvest technique, but controversy exists over which aspiration method optimizes cellular yield while taking patient comfort and risk into consideration. PURPOSE: To compare a single- versus multiple-site bone marrow aspiration technique to determine which would generate a sufficient volume of high-quality BMA for concentration into a BMC graft. The level of pain experienced by the patient was monitored, since patient comfort should be included in the determination of a safe and effective aspiration technique. STUDY DESIGN: Controlled laboratory study and cohort study; Level of evidence, 2. METHODS: BMC samples from 6 patients were sent to an outside source for laboratory analysis. All 6 participants underwent bilateral bone marrow aspiration. Each patient received both techniques at the posterior iliac crest: one side underwent a multiple-site aspiration technique, and the contralateral side underwent a single-site technique with needle redirection. BMA and BMC samples were analyzed for concentrations white blood cells, total nucleated cells, red blood cells, neutrophils, and hematopoietic stem cells. One BMC sample was cultured, and MSC analysis was performed via flow cytometry. All patients underwent monitoring of pain scores during and after the procedure through a visual analog pain scale at 24 hours, 72 hours, and 7 days after BMA. RESULTS: No significant difference was found between the cell ratios of the single- and multiple-site groups. Both aspiration techniques were found to provide ample colony-forming units without a marked difference in appearance. Additionally, no significant difference was found between groups with regard to MSC numbers. Pain during and 24 hours after the procedure was significantly greater with the multiple-site method than the single-insertion method. CONCLUSION: The single-insertion method produced final cellular concentrations and culture results that were not significantly different from those of a multiple-insertion method. Additionally, the single-insertion site technique was significantly less painful to the patient at the time of the procedure as well as 24 hours after aspiration. CLINICAL RELEVANCE: The results of this study indicated that a high-quality bone marrow aspirate is possible with a single-stick aspiration method.