In the United States 7.9 million fractures occur annually. Between 5% and 10% of these fractures result in delayed or impaired healing. More than 1.5 million bone-grafting procedures are performed each year. Iliac crest bone graft has long been considered the gold standard for autogenous bone graft because of its osteoconductive, osteoinductive, and osteogenic properties ; however, it is associated with significant donor site morbidity and increased operative time. The Reamer-Irrigator-Aspirator (RIA; Synthes, USA, Paoli, PA) was initially developed to potentially reduce the embolic load associated with reaming the femur for intramedullary nailing in trauma. Subsequently it has been noted that the reamings are biologically active and may provide a source of autogenous bone similar to iliac crest in efficacy, but with fewer donor site complications. The RIA system typically uses a single filter to capture the bony reaming debris from the RIA cutting head. Recently it has been noted that the irrigating fluid effluent may also contain significant amounts of growth factors and mesenchymal stem cells.

The purpose of this paper is twofold. First, we report on our novel technique of using a second filter containing beta-tricalcium phosphate (TCP) as a graft extender while using the RIA system. Second, we sought to identify whether growth factors known to be present in the bony reaming debris and fluid effluent are also present in the collections from the TCP filter.