Length of storage of transfused red blood cells and risk of prosthetic joint infection after primary knee arthroplasty.

The aim of our study was to determine the potential influence of blood transfusion and the length of storage of packed red blood cells (RBC) on prosthetic joint infection after primary knee arthroplasty. From November 2007 to November 2009, all variables potentially associated with deep infection were registered in 1331 consecutive patients who underwent total knee arthroplasty. Infection was diagnosed in 32 (2.4%) patients. After adjusting for important variables, blood transfusion with RBCs stored >14days was the strongest predictive factor for prosthetic joint infection within 90days after primary knee arthroplasty (OR: 5.9, 95% CI: 2.6-13.2, P < 0.001). Blood saving techniques are desirable to reduce perioperative blood transfusion.