The role of timing of tourniquet release and cementing on perioperative blood loss in total knee replacement.

The purpose of our study is to estimate the effect of tourniquet release and cementing in perioperative blood loss associated with total knee arthroplasty. Eighty patients were randomly allocated into two equal groups concerning the timing of tourniquet release. Group A: patients with tourniquet release and haemostasis before wound closure and group B: patients with tourniquet release after skin closure and compressive bandaging. These groups were further subdivided in two subgroups (+ and -) depending on cementing or not of the tibial tray only. The total blood loss averaged 961 ml in group A and 692 ml in group B, while it was estimated 763 ml in the cemented group and 890 ml in the non-cemented group. The total blood loss within subgroups was Group A+ 904 ml, Group A- 1017 ml, Group B+ 622 ml and Group B- 762 ml. The mean number of blood units transfused per patient was 4.7 in Group A and 4.0 in Group B, while the mean operating time was 79 min and 66 min, respectively. Complications such as deep vein thrombosis, haematomata and minor wound complications occurred in patients of Group A and Group B, 0 and 2, 0 and 2, 8 and 11, respectively. Intraoperative tourniquet release seems to be related with significantly greater blood loss (P<0.001) and demands in blood transfusion P<0.05 as well as a longer operating time (P<0.001). Cementing of total knee replacements has a better haemostatic role compared to non-cemented prosthesis (P<0.05). Even though complications were more in postoperative tourniquet release group, no statistically significant difference was found between group A and B. Postoperative tourniquet release seems to offer better conditions of haemostasis probably due to the better controlled fibrolytic activity.