Osteogenic Cell Viability in Bone Graft

Although iliac crest bone grafting is the gold standard for autogenous bone grafting
procedures, limited quantity in some individuals and donor site morbidity have lead surgeons
to look for alternative harvest sites or sources such as allograft or osteobiologics. Of
these alternative harvest sites is the femoral shaft. Intramedullary contents from reaming
are composed of bone marrow, and blood and bone spicules. In this respect, the reamed
contents are similar to the bone routinely harvested from the iliac crest. Studies have
shown that despite the reaming process using standard reamers, cells maintain their
viability and are able to produce new bone. However, the addition of aspiration and
irrigation used in the RIA system could potentially compromise the harvested cell viability
and limit their osteogenic potential. In addition, Wenisch et al. have concluded that the
harvested cells using standard intramedullary reamers not only proceed toward osteogenic
differentiation, but also can be directed toward neurogenic differentiation. This suggests
that reaming debris is a viable source of stem cells as well. RIA allows for these cells to
be harvested. It is our hypothesis that the intramedullary contents harvested using the RIA
system is similar to ICBG in cell viability and osteogenic potential.

Inclusion Criteria:

- Subjects age 18 years or older

- Subjects undergoing a bone grafting procedure, either using an iliac crest or RIA
system harvesting technique, or

- Subjects undergoing reamed femoral intramedullary nailing using the RIA reaming
technique

Exclusion Criteria:

- Subjects under age 18

- Subjects with a history of: leukemia; cancer with bone metastases; renal failure,
receiving dialysis; or on immunosuppressive medications