Preparation of femoral medullary canal induces fat embolism during total hip replacement: an experimental study / 中华骨科杂志

ABSTRACT

Objective To investigate the effects of medullary reaming on respiratory and circulatory system in dog model during total hip replacement. Methods Twelve mongrels were randomly divided into two groups. In control group, femoral necks were cut while femoral canals were not disturbed. In experimental group, femoral canals were reamed with femoral rasps as done in total hip replacement. The changes of hemodynamics and pulmonary function were monitored during perioperative period. The postmortem pulmonary tissues were studied by pathological examination. Results No fat embolus was found in any lung sections of control group. Meanwhile, pulmonary fat emboli were found in all of experimental group. After fat embolism happened, cardiopulmonary effects included increased pulmonary artery pressure, pulmonary shunt and pulmonary vascular resistance accompanying a decrease in partial pressure of oxygen and cardiac output. There is statistically significant difference in response between the two groups. Conclusion The present study showed that embolic events and intraoperative pulmonary impairment are common during reaming of femoral medullary canal in total hip replacements. Further research can be made with this model in order to reduce the risk of fat embolism syndrome.