The influence of a one-step reamer-irrigator-aspirator technique on the intramedullary pressure in the pig femur

SummaryBackgroundIncreased 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 methodIn 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.ResultsThere 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.ConclusionThe 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.