The treatment of femoral shaft fractures using intramedullary interlocked nails with and without intramedullary reaming: a preliminary report

Effect of femoral fracture and intramedullary fixation on lung capillary leak

BACKGROUND

Pulmonary injury is an important complication in the trauma patient with long-bone fractures. The purpose of this study was to determine the effect of femoral fracture or fracture and intramedullary fixation on lung capillary leak. The contribution of leukocytes to lung injury in this model was also determined.

METHODS

The pulmonary capillary filtration coefficient was determined in lungs of rats after femur fracture or fracture and reamed or unreamed intramedullary fixation. Pulmonary arterial vascular resistance and lung neutrophil content were also determined.

RESULTS

Fracture alone did not cause lung injury, whereas fracture and intramedullary fixation elicited lung capillary leak. Fracture alone and intramedullary fixation increased pulmonary vascular resistance, whereas unreamed intramedullary fixation caused lung leukosequestration.

CONCLUSION

Femoral fracture alone does not cause an increase in pulmonary microvascular permeability. Femoral fracture and intramedullary fixation causes lung capillary leak, which is not increased by reaming the femoral canal.

The effect of reamed and nonreamed intramedullary nailing on fracture healing

Intramedullary nailing has revolutionized the treatment of fractures. It is important to be aware of the biological and mechanical effects of reaming and nailing on bone. Most nails are substantially stiffer than bone, but because of their location in the medullary canal do not have nearly as adverse an effect on callus strength as plates. Reaming and nailing embolizes marrow contents into the systemic circulation and reduces blood flow to the total bone and cortex by 30% to 80%. This results in a hyperemic reaction that revascularizes the cortex depending on the type of nail used. Preservation of the soft tissue envelope around the fracture enhances this response resulting in fracture healing ratio of 98% when closed nailing techniques are used. The primary advantage of nonreamed nailing is better preservation of the blood supply to the cortex whereas the major advantage of reamed nailing is a more rigid construction, stronger implants, and earlier fracture union.