Analysis of lower extremity embolic material after total knee arthroplasty in a canine model.

Emboli assumed to consist of fat, marrow, cement, and bone are generated during total knee arthroplasty. This study collected and identified the constituents of the embolic debris and assessed the effects of intramedullary cutting guides in a canine model. During cemented knee arthroplasties with or without the use of intramedullary guides, all embolic debris was collected in a single lobe of lung. In dogs using intramedullary guides, transesophageal echocardiography revealed a sustained embolic shower, and histologically marked amounts of emboli obstructed the pulmonary vasculature. The emboli were composed of fat cells and hematopoietic cells (marrow elements) interspersed with free fat globules. Marrow elements are the primary constituents of the emboli generated during total knee arthroplasty. Intramedullary guides increased debris generation.