Intramedullary pressure and bone marrow fat intravasation in unreamed femoral nailing

Objective: To investigate whether intramedullary pressure and bone marrow fat embolization are different in unreamed compared with conventional reamed femoral nailing, The null hypothesis is that there is no difference between the two techniques, Design: A prospective consecutive nonrandomized clinical trial. Methods: Intramedullary pressure was measured in the distal femoral fracture fragment at the supracondylar region, Bone marrow fat intravasation was measured bg means of the modified Gurd-test, Monitoring was carried out in 31 unreamed and eight reamed intramedullary femoral nailing procedures, Results: Intramedullary pressure increased in the unreamed group to 82 +/- 11 mm Hg during the insertion of 9-mm and 10-mm nails and in the reamed group to 396 +/- 85 nun Hg during reaming of the medullary cavity, Insertion of nails after reaming Bed to an increase in intramedullary pressure of 79 +/- 13 mm Hg, A positive correlation between fat intravasation and intramedullary pressure was found in each group (r(s) = 0.73), resulting in less liberation of hone marrow fat in the unreamed group than in the seamed. group, Conclusions: Intramedullary pressure increased significantly in the reamed more than in the unreamed group, Bone marrow fat intravasation depended on the rise in intramedullary pressure, and occurred less frequently in unreamed than in reamed intramedullary femoral fracture stabilization.