Background: Increased intramedullary pressure in the femoral cavity causes intravasation of bone marrow content to the circulation which may lead to occlusion of pulmonary vessels and cardiorespiratory dysfunction. A one-step reamer-irrigator-aspirator (RIA) technique has been developed to reduce the intramedullary pressure (IMP) during the reaming procedure. This study was design to compare IMP with a standard reaming technique with IMP during reaming with the RIA system with a hypothesis that the RIA system would involve lower pressures.
Material and method: In a randomised study in 19 Norwegian landrace pigs reamed intramedullary nailing was performed with two different reamer devices. Nine animals were operated with a traditional reamer and 10 animals with RIA. One animal in the RIA group was excluded due to a perioperative femoral fracture, and three animals in the traditional group were excluded due to a perforation of the distal medial femoral cortex. The intramedullary pressure was registrated with a transducer-tipped pressure monitoring catheter during reaming.
Results: There was a significantly higher intramedullary pressure (P<0.05) during reaming in the traditional reamer group (mean 188+/-38 mmHg) than in the RIA group (mean 33+/-8 mmHg). Intramedullary pressures recorded before surgery, at the opening of the femoral cavity with an awl, by insertion of a guide wire, at insertion of the intramedullary nail, and 10 min after nail insertion showed no significant differences between the groups.
Conclusion: The use of a one-step reamer-irrigator-aspirator technique in the pig femur induced less intramedullary pressure increase than the use of a traditional reamer.