PULMONARY FAT-EMBOLISM IN REVISION HIP-ARTHROPLASTY

Unilateral cemented hip hemiarthroplasty was done on 16 dogs who subse quently had revision arthroplasty and who were divided into 1 control and 3 experimental groups: The first group had cement extraction using osteotomes; the second, using a high speed burr; the third, an ultras onic tool. Hemodynamic and transesophageal echocardiographic monitorin g were done. Postmortem pulmonary specimens were examined for differen ces in the quantity of fat emboli, There was a significant increase in emboli with the ultrasonic tool as compared with osteotomes and high speed burr, There was no significant difference in emboli between the osteotomes and high speed burr. Fat emboli syndrome is related to mech anical compression of the femoral canal. The ultrasonic instrument was unique in its tendency to cause large embolic showers, especially dur ing extraction of the distal cement plug, In these young dogs, minimal hemodynamic changes and no cardiac dysrhythmias occurred, which in pa rt may be attributed to their good health. These changes may remain su bclinical for patients with good cardiorespiratory reserve, or may bec ome life threatening for those with poor reserve, By outlining the mec hanisms of fat embolism in revision total hip arthroplasty, it may be possible to decrease future morbidity, especially in patients who freq uently have cardiopulmonary disease.