Unreamed or RIA reamed nailing: an experimental sheep study using comparative histological assessment of affected...

The purpose of the present study was to evaluate the Reamer/Irrigator/Aspirator (RIA), a reaming system designed to incorporate the advantages of irrigation and suction for every day clinical use. The evaluation process was focused on the displacement of the medullary content and its impact on cortical perfusion. The results of the RIA reamed nailing were compared to conventional non-reamed nailing (NRN). The tibia of the sheep was used as an acute fracture model. The fracture and nailing procedure was followed by intravital staining with Procion red. The effects on cortical perfusion (Procion red staining) were addressed in polymer embedded sections and cryosections. Sudan III stained cryosections were evaluated with respect to the cortical fat distribution. After irrigation and suction minute amounts of fat were observed in the cortex, whereas after non-reamed nailing the endosteal third of the cortical bone was penetrated with fat. Non-reamed nailing acutely showed better perfusion in the endosteal tenth and periosteal third of the cortical bone, after irrigation and suction reaming perfusion was preserved to a lesser degree. Irrigation and suction significantly reduces fat intravasation, and thus the danger of system-wide damage. Therefore, the Reamer/Irrigator/Aspirator is as efficient as its experimental predecessors.