Fat Embolism Can Occur Simultaneously with BCIS
Yes, fat embolism can occur simultaneously with bone cement implantation syndrome (BCIS), as fat embolism is actually one of the primary pathophysiologic mechanisms underlying BCIS itself.
Understanding the Relationship
The evidence clearly demonstrates that BCIS and fat embolism are not separate entities but rather interconnected phenomena. BCIS is fundamentally caused by embolization of intramedullary contents—including fat and bone marrow—into the pulmonary circulation 1.
Pathophysiologic Mechanism
The 2015 Association of Anaesthetists guideline explicitly recommends using "a pressurised lavage system to clean the endosteal bone of fat and marrow contents" during femoral canal preparation, directly acknowledging that fat is a key component of the embolic material responsible for BCIS 1.
Historical research from 1980 established that BCIS "reveals itself as cardiorespiratory sequelae of a disseminated pulmonary embolism which is originating in intramedullary contents, squeezed intravasal" 2. Post-mortem findings in documented BCIS cases have shown "multiorgan disseminated microembolization of bone marrow and amorphous cement material" 3.
Key Clinical Points
Fat embolism is not a separate complication from BCIS—it is the mechanism: When femoral canal instrumentation occurs, intramedullary contents (fat, marrow, bone debris) are forced into the venous circulation, causing the cardiovascular collapse characteristic of BCIS 1, 2
BCIS occurs even without cement: Recent evidence shows BCIS can occur in uncemented arthroplasty with incidence ranging from 0.0% to 21.8%, confirming that the embolic material (fat and marrow), not cement itself, is the primary culprit 4, 5
The term "BCIS" may be misleading: The syndrome should perhaps be understood as "intramedullary embolization syndrome" since fat embolism occurs regardless of cement use 5
Clinical Implications
During any procedure breaching the femoral canal—cemented or uncemented hip arthroplasty, intramedullary nailing—clinicians should anticipate fat embolism as the underlying mechanism of cardiovascular compromise 1, 6. The surgical techniques recommended to prevent BCIS (pressurized lavage, distal suction catheter, avoiding excessive pressurization) are specifically designed to minimize fat and marrow embolization 1.
Common Pitfall: Attributing BCIS solely to cement toxicity when the primary mechanism is mechanical embolization of fat and marrow contents. This misconception can lead to inadequate preventive measures during uncemented procedures where fat embolism risk remains substantial.