WHAT IS THE IMPORTANCE OF CFU-F COUNTS COMPARED TO NUCLEATED CELL COUNTS?

There is no constant ratio between average marrow cellularity as measured by number of total nucleated cells per mL and the number of cfu-f. Hernigou et al in several authoritative studies linked clinical outcomes in non-union and osteonecrosis to the number of cfu-f cells in the graft. Controlling for volume, Hernigou et al noted that 70% of the variation in cfu-f from patient to patient was due to variations in the quality of the marrow aspirate or idiosyncratic to the patient with the remaining variation being due to the  number of nucleated cells per mL in the aspirate. Statistically, the only variable Hernigou reported to be significant was cfu-f and not nucleated cells per mL. Interestingly, cfu-f is found frequently in marrow and very rarely in peripheral blood. From Hernigou “Therefore, it seems reasonable to suggest that a graft needs to contain greater than 1000 progenitors / cm ^3” 

Hernigou et al Treatment of Osteonecrosis with autologous bone marrow grafting Clinical Orthopaedics and Realted Research number 405, pp 14-23 

Hernigou P, et al Percutaneous Autologous Bone-Marrow Grafting for Nonunions – Influence of the Number and Concentration of Progenitor Cells The Journal of Bone and Joint” Volume 87-A No 7 July 2005