Risk factors of blood transfusion in knee arthroplasty

OBJECTIVES: The amount of blood transfusion after knee arthroplasty seem to vary in different reported study. We carried out a retrospective study to analysis pre-operative risk factors for blood transfusion in patient whom underwent knee arthroplasty in our institution. METHODS: A retrospective study of 190 patients treated with 194 procedure (186 unilateral knee arthroplasty, 4 bilateral knee arthroplasty) from November 2014 to October 2015 was analyzed. A univariate analysis was performed to establish the relationship between all variables and the need for postoperative transfusion. Variables that were determined to have significant relationship were include in a multivariable analysis.. RESULTS: The univariate analysis revealed a significant relationship between need for postoperative blood transfusion and preoperative hemoglobin levels, surgical technique, arthrotomy approach, DVT prophylaxis, operative blood loss, surgical technique and surgeon experience. The multivariate analysis identified a significant relationship between need for transfusion and preoperative hemoglobin level, surgical technique and operative blood loss. Patients with a preoperative hemoglobin less than 12 g/dL had a 5.1 times greater risk of having a transfusion than those with a hemoglobin level ≥ 12 g/dL. The surgical technique with computer assisted surgery had a 0.15 times lesser risk of having a transfusion than those with the conventional technique. CONCLUSION: The preoperative hemoglobin level < 12 g/dL was shown to increase risk of the need for blood transfusion after knee arthroplasty, while computer assist surgery total knee arthroplasty was shown to decrease risk of blood transfusion. We suggest that patients with preoperative hemoglobin < 12 g/dL need to be crossmatching PRC in pre-operative steps.