Proximal Humerus and Ilium Are Reliable Sources of Bone Marrow Aspirates for Biologic Augmentation During Arthroscopic Surgery.

Purpose: The purpose of this study was to evaluate the number of colony-forming units (CFUs) derived from concentrated bone marrow aspirates (BMAs) that were processed following arthroscopic harvest from either the proximal humerus or the body of the ilium during biologic augmentation of the rotator cuff and acetabular labral repairs.

Methods: Between November 2014 and January 2019, BMA was harvested from the proximal humerus (n = 89) and the body of the ilium (n = 30) during arthroscopic surgery. Following concentration of the aspirate, a 0.5-mL aliquot was further processed and the number of nucleated cells (NC) was counted. Each aliquot was cultured until CFUs were quantifiable. Fluorescence-activated cell sorting analysis and quantitative polymerase chain reaction was performed to confirm presence of mesenchymal stem cells. BMA harvest sites were prospectively assessed and evaluated for differences in age, sex, volume of aspirated BM, and CFUs per milliliter of BMA.

Results: The prevalence (38.57 ± 27.92 vs. 56.00 ± 25.60 CFUs per 10 nucleated cells) and concentration (979.17 ± 740.31 vs. 1,516.62 ± 763.63 CFUs per 1.0 mL BMA) of CFUs was significantly higher (P < .001, respectively) for BMA harvested from the proximal humerus. Additionally, the estimated total number of cells was significantly higher (P = .013) in BMA from the proximal humerus (97,529.00 ± 91,064.01 vs. 130,552.4 ± 85,294.2). There was no significant difference between groups regarding BMA volume (91.67 ± 18.77 vs. 85.63 ± 35.61 mL; P = .286) and NC count (24.01 ± 5.13 vs. 27.07 ± 6.28 × 10 per mL BMA; P = .061). The mean age was significantly lower (P < .001) in patients with BMA being harvested from the ilium (30.18 ± 7.63 vs. 56.82 ± 7.08 years). Patient sex and age had no significant influence on cellular measures within groups (P > .05, respectively).

Conclusion: Both proximal humerus and the body of the ilium can be considered reliable sources of bone marrow aspirate for the use in biologic augmentation during their respective arthroscopic surgery. Samples of bone marrow aspirate from the proximal humerus yielded a significantly higher amount of CFUs when compared with samples of BMA obtained from the ilium.

Level Of Evidence: Level II- prospective laboratorial study.