Blood management protocols attempt to reduce blood loss by strategies including autologous blood donation, red cell salvage, normovolaemic haemodilution and haemostatic agents such as tranexamic acid (TXA). TXA usage in particular has become increasingly commonplace with numerous studies demonstrating a significant reduction in peri-operative blood loss and proportion of patients requiring transfusion, without increasing the risk of venous thromboembolism. Tourniquet usage has now become ubiquitous in TKA operations with reported benefits of improved visualization, shorter operative time and decreased intra-operative bleeding. However, its use is not without considerable complications including wounding dehiscence, increased venous thromboembolism, superficial wound infection and skin blistering. It is therefore imperative that we review tourniquet usage in light of ever evolving blood management strategies. The aim of this study was to evaluate the effect of stopping tourniquet usage in primary TKRs, performed by an experienced surgeon, in light of new blood reduction measures, such as a TXA.

A retrospective analysis identified a total of 31 patients who underwent primary TKR without the use of a tourniquet from January 2018 to March 2019. This was compared to an earlier group of patients from the same surgeon undergoing TKR with the use of a tourniquet; dating from July 2016 to November 2017. All surgeries were performed within the same hospital (CXH). Peri-operative factors and outcome measures were collected for analysis.

There was no significant difference in post-operative haemoglobin drop (Tourniquet, 23.1 g/L; No Tourniquet, 24.4 g/: p=0.604) and fall in haematocrit (Tourniquet, 0.082; No Tourniquet, 0.087: p=0.604). Allogenic blood transfusion rates were the same in both groups at 12.9% (2 patients) and blood loss was not found to be significantly different (Tourniquet, 1067ml; No tourniquet, 1058mls). No significant difference was found in operative time (Tourniquet, 103 minutes; No Tourniquet, 111.7 minutes: p=0.152) or length of stay (Tourniquet, 5.5 days; No Tourniquet, 5.2 days: p=0.516). Tranexamic acid usage was not found to be significant (p=1.000). ROM of motion and analgesia requirement was significantly better in the no tourniquet group on one post-operative day out of five analysed (p=0.025, p=00.011). No post-operative thromboembolic events were reported in either group. There was no significant difference in readmission rates (p=0.492) or complications (p=0.238).

The increase in minor complications and potential increased VTE risk with tourniquet usage must be balanced against an improved visual field and reduced blood loss in TKR patients. Our study found no difference in post-operative blood loss and transfusion rates between tourniquet and no tourniquet groups. With ever evolving and improving blood loss management strategies, including the use of TXA, the application of tourniquet may not be needed. Further prospective RCTs are needed to assess the impact of tourniquet usage in light of this.