METASTATIC DISEASE AS A RISK FACTOR FOR ADVERSE EVENTS DURING CEMENTED LONG-STEM FEMORAL ARTHROPLASTY

Herrenbruck T, Erickson EW, Damron TA, Heiner J, SUNY HSC at Syracuse and University of Wisconsin

INTRODUCTION: The hypothesis examined was that the incidence of fat embolization is more frequent among those patients who undergo long-stem cemented femoral arthroplasty in the setting of metastatic disease.

METHODS: Anesthesia, clinical, and operative notes for all cases of cemented long-stem femoral arthroplasty performed were reviewed for predisposing factors and evidence of adverse clinical events including fat embolization. The study group was comprised of 60 patients, including 19 revision cases and 41 metastatic cases. Significant events were defined as including intraoperative or perioperative drops in systolic blood pressure of at least 30 points or mean arterial pressure of 15 points, mean arterial pressure less than 70, oxygen saturation of less than 95%, or administration of sympathomimmetics.

RESULTS: Significant events occurred intraoperatively or early postoperatively in 30/60 patients (50%) overall. These adverse events were no more common in the metastatic group (20/41, 48%) than the revision cases (10/19, 52%). However, these events were more likely to occur following cementation in the metastatic cases ( 20/41, 48.8%) than in the revision cases (2/19, 10.5%). Administration of sympathomimmetics was necessary intraoperatively or immediately postoperatively in 15/60 cases (25%). The percentage of patients requiring such treatment did not differ between the metastatic cases (10/41, 24%) and the revision cases (5/19, 26%). In three cases, patients experienced profound hypotension and desaturation immediately following cementation and were comatose post-operatively. One of these patients died, while the others remained comatose up to 12 days postoperatively. Such catastrophic embolization and coma was only observed in the metastatic cases (3/41, 7%). There were no cases of cardiac arrest. Only one mortality occurred during hospitalization (1.6%).

CONCLUSIONS: The overall frequency of significant perioperative adverse clinical events does not appear to differ between those patients who undergo this procedure for metastatic disease versus those for arthroplasty revision. However, the patients with metastatic disease are more likely to experience these events immediately following cementation, supporting fat embolization as the specific cause. In addition, catastrophic hypotension, desaturation, and coma were only observed in the metasatic patients in this study, emphasizing the need for appropriate education during preoperative informed consent.