Concentrated Bone Marrow Aspirate is More Cellular and Proliferative when Harvested from the PSIS than the Proximal Humerus.

PURPOSE The purpose of this study is to determine whether cBMA from the posterior superior iliac spine (PSIS) or proximal humerus (PH) produces a more productive cellular harvest in patients undergoing arthroscopic rotator cuff repair. METHODS Patients under 80 years old undergoing surgery for arthroscopic rotator cuff repair were enrolled. Two sixty mL aliquots of BMA were harvested from each subject, one from the PSIS and one from the PH. Each aliquot was processed independently to create cBMA. Cellular composition was determined using an automated hemocytometer and proliferative potential was studied with colony forming unit (CFU) assays. RESULTS Twelve patients were recruited (7 male, 5 female). The average age was 64.3 years (range 46.1-77.25 years) with BMI 26.8 (range 20.0-34.3). The average TNC from PH was 18.7 x 106 cells/mL (95% CI: 4.4-33.0, SD: 24.8) with 3.9 CFU/mL (95% CI: 0.3-7.5, SD: 5.7). The average TNC count from the PSIS was 55.9 x 106 cells/mL (95% CI: 25.3-86.4, SD: 52.9) with 32.5 CFU/mL (95% CI:11.5-53.5, SD: 33.1). The PSIS had a 3.0 times greater total nucleated cell yield (p=0.014) and 8.3 times greater number of CFU/mL (p=0.024) when compared to the PH. The average harvest time from the PSIS was 5.6 min and from the PH was 11.0 min (p=0.043); harvest time did not account for additional time to prep and drape the PSIS. CONCLUSIONS CBMA harvested from the PSIS resulted in a 3.0 times greater cellular yield and an 8.3 times greater proliferative product than cBMA from the PH. CLINICAL RELEVANCE When a more cellular cBMA product is sought to augment RTC repair surgery, the PSIS is the preferred site for harvest.