OTA 1997 Posters - Femur Fractures

The Perioperative Pulmonary Effects of Intramedullary Rodding of the Femur

James A. Volglino, MD, Henry Marano, MD, Richard S. Collins, MD, Bernard Boal, MD

Woodmere, New York, USA

Purpose: To determine if there is a relationship between intramedullary rod fixation of adult femoral shaft fractures and the fat embolism or adult respiratory distress syndromes.

Methods: This prospective study was started in December 1994 and is ongoing. The study group includes adult patients with acute femoral fractures and those with impending pathologic fractures. Preoperative evaluation includes: a routine chest radiograph; mental status examination; notation of petechial rash; urine testing for fat; and a baseline arterial blood gas. Intraoperative studies are; serial arterial blood gas determinations during reaming and rod placement; an echocardiogram (transthoracic); and end-tidal CO2 determinations. Postoperative studies include: mental status examination; notation of petechial rash; urine testing for fat; and a pulmonary VQ scan. Any patient with evidence of preoperative fat embolism or respiratory distress syndrome is excluded from the study.

Results: Twenty-eight patients have been studied to date; all have undergone intramedullary rodding for femoral stabilization. Of the twenty-one patients with acute femoral fractures, ten involved multiple trauma. Seven patients had impending pathologic fractures. A total of twenty-three patients underwent traditional reamed intramedullary nailing, while five underwent 'unreamed' femoral nailing. Two patients had several days of postoperative hypoxia consistent with mild respiratory distress syndromes. One of these patients had concomitant chest trauma, while the other had perioperative anemia. Intraoperative blood gas data was analyzed from twenty-five patients. All patients demonstrated minor intraoperative alterations in pCO2 and HCO3, which resolved spontaneously and did not appear to be clinically significant. During reaming and rodding, echogenic 'emboli' were noted in the right ventricles in four of ten patients, but could not be associated with either postoperative hypoxia or pulmonary perfusion defects. None of twenty-three postop VQ scans revealed any perfusion defects that could be associated with observed emboli, perioperative hypoxia or ABG changes.

Discussion and Conclusions: This preliminary data supports earlier animal studies which indicate that echogenic emboli and nonsignificant arterial blood gas alterations do occur during intramedullary roddings. While fat embolism or adult respiratory distress syndromes are rare, a concomitant lung injury or perioperative anemia may place the patient at greater risk for pulmonary complications perioperatively. In a closely monitored and diverse group it was difficult to detect any consistent subclinical pulmonary changes from the intramedullary femoral procedure.