Introduction: Knee replacement surgery is associated with minimal intraoperative blood loss, but marked postoperativelloss.

Allogenic blood transfusions are associated with known risks.

The need to establish programmes of blood conservation in knee replacement surgery becomes evident.

We present a retrospective comparative study of 3 blood salvage methods used in TKR: autologous blood donation, cell saver and tranexamico acid.

The purpose of this study is to asses the results of tranexamic acid compared with other used methods.

Material and methods: We reviewed 90 TKR operated during 2002–2003 with the same technique and by the same surgical team.

3 patients cohorts have been done based on the blood saving method used,

Patients and surgical variables were recorded, to confirm the homogeneity of the groups.

Haemoglobin and hematocrit levels in preoperative, early postoperative and late postoperative were collected, as well as blood loss and the number of blood units transfused.

Results: The statistic analysis of the 3 groups didn’t show any differences between them, assuring the homogeneity.

ANOVA statistical analysis was done, showing significative differences in the early postoperative Hb and HTC, 9.4 g/dL −28.1% in autologous group, 9.6g/dL−28.5% in cell saver group and 10.8g/dl−31.4% in the tranexamic acid group.

Total blood loss was 1088.5 mL in the autologous group, 1080mL in the cell saver group and 690.3 mL in the tranexamic acid group, showing significant differences (p.< 0.001).

The autologous group received 1.4 units of blood per patient, compared with 0.6 in the cell saver group and 0.2 in the tranexamic acid group (p< 0.05).

Conclusions: We conclude that the use of tranexamic acid in total knee replacement reduces postoperative blood loss, keeps Hb and HTC during the postoperative and significatively reduces the need of blood transfusion compared with other systems.