Increased osteogenic capacity of Reamer/Irrigator/Aspirator derived mesenchymal stem cells.

INTRODUCTION: Donor-site morbidity, complications and availability remain concerns in autologous bone grafting today. The Reamer/Irrigator/Aspirator system (RIA) provides an alternative method to overcome these problems. According to literature, RIA graft possesses a higher osteogenic potency. This study compares iliac crest and RIA graft performance by determining their in vitro osteogenic capacity in a porcine model.

METHODS: Osteogenic capacity and cell content was determined in RIA and iliac crest bone grafts harvested from six female domestic white pigs. Cells initially washed off, and cells harvested with collagenase were analysed separately and in combination. Alkaline phosphatase expression (ALP) and cell numbers were evaluated after 7 and 14 days of culture. Matrix mineralisation was quantified after 14 days.

RESULTS: Cell cultures showed a significant increase of matrix mineralisation by RIA-derived cells compared to iliac crest bone graft (p = 0.0313). The yield of collagenase derived cells was increased in the RIA group and a synergy between washed off and collagenase derived cells was observed. Cell proliferation was similar in both groups.

DISCUSSION: The osteogenic differentiation capacity of cell populations isolated from the RIA derived bone graft surpasses that of iliac crest derived cells. It is proposed that the observed effect can be attributed to the origin of the cells and to the specific action of the RIA system. This study provides further evidence indicating that RIA bone graft provides superior osteogenic properties compared to iliac crest bone graft.