Allogeneic blood transfusion does not increase the risk of wound infection in total knee arthroplasty

Background and Objective Allogeneic blood transfusion has been reported to increase the risk of postoperative infection in arthroplasty though the results are inconclusive. Data from a previous clinical trial on antibiotic prophylaxis in knee arthroplasty were analysed to gain further insight into the relationship between wound infection and both blood transfusion and the storage time of transfused RBCs. Materials and Methods A total of 910 consecutive patients undergoing primary knee arthroplasty were prospectively followed for 12 months after surgery. The main outcome was wound infection, either superficial or deep-tissue. Possible predictors for wound infection included the patient's age and sex, preoperative physical status, time under leg ischaemia, postoperative fluid drainage, and the number and length of storage of transfused RBCs. Results Deep tissue infection was diagnosed in 28 (3%) patients, superficial infection in 25 (2 center dot 7%) and cellulitis in eight (0 center dot 8%) patients. Transfusion of at least one blood unit had been given to 22 (36%) of the 61 patients who later developed wound infection and 313 (36%) of those who did not (P > 0 center dot 05). Patients who developed wound infection had a significantly poorer physical status and longer time of leg ischaemia. There was no significant difference between both groups of patients in either the amount or the length of storage of transfused RBC units. Conclusion This study failed to find any association between the incidence of wound infection after knee arthroplasty and allogeneic transfusion.