Quantitative analysis of growth factors from a second filter using the Reamer-Irrigator-Aspirator system: description of a novel technique.

Use of the Reamer-Irrigator-Aspirator (RIA) as a source of autogenous bone graft in the treatment of nonunions is increasing. 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. We also quantify growth factor concentrations in the collections from the TCP filter. A second filter attached in series with the standard RIA filtration system yields TCP with substantial concentrations of bioactive proteins that are equal to those seen in the bone graft that is harvested in the first filter.