Background: Pulmonary damage after reamed or unreamed femoral nailing has been controversial in clinical and experimental studies. We investigated changes in pulmonary function and coagulatory response in normal lungs of sheep after reamed or unreamed intramedullary nailing of an unfractured femur.

Methods: We used three groups of sheep (each group, n = 6): reamed femoral nailing (RFN); unreamed femoral nailing (UFN); and sham control group. Femoral osteotomies and lung contusions were not made. Hemodynamic monitoring data and blood gas data (BGD) were recorded, and blood samples for biochemistry (antithrombin III, lipid peroxidase and fibrinogen) were collected 0 to 6 hours after nailing. Bronchoalveolar lavage fluid (BALF) and myeloperoxidase (MPO) activity in pulmonary tissue were analyzed 6 hours after nailing.

Results: There were no significant differences in time course of hemodynamic monitoring data, BGD, or biochemical data among the three groups. In BALF analysis, the lipid-laden cell count in the RFN group was higher than those of the other groups, and MPO activity was highest in the RFN group.

Conclusion: RFN did not affect pulmonary function at the physiologic level or affect the coagulatory system at the acute stage, but RFN under non-damaged conditions could lead to leukocyte activation in lung tissue without worse alteration of alveolar permeability in the acute post-operative course.