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.

Material and method: In a randomized study in 19 Nor-wegian landrace pigs reamed intramedullary nailing was performed with two different reamer devices. Nine animals were operated with a traditional reamer and ten animals with RIA. One animal in the RIA group was excluded due to a perioperative femoral fracture, and three animals in the traditional group 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: The highest intramedullary pressure during reaming was mean 33 mm Hg in the RIA group and 188 mm Hg in the traditional reamer group. This difference was significant (P < 0.05). 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 ten minutes 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.