Technical issues in harvesting and concentrating stem cells (bone marrow and adipose).

The area of regenerative medicine, through the use of cell-based or biologic therapies, affords various options even with the choice of autologous stem cells and requires the clinician to use the currently evolving science along with the art of medicine. Potential sources for stem cells are embryos, fetuses, and adults (adipose tissue or adult cells, usually from skin [induced pluripotent], amniotic fluid, cartilage, bone marrow, menstrual blood, peripheral blood, placenta, skin, teeth, synovium, or umbilical cord blood). Issues regarding the source of stem cells include ethical and political/regulatory concerns, cell frequency, ease/difficulty of extraction, ease/difficulty of graft preparation, and host reaction to the implant. The most common sources of stem cells for orthopedic conditions are adipose tissue and bone marrow. Various opinions are expressed within the medical literature for and against both of these stem cell sources. This article will review patient concerns and preparation for obtaining cells; equipment, supplies, and staffing for the procedures; techniques, pearls, pitfalls, and risks of the procedures; and the manner of/options for processing the cells.