No benefit of using pneumatic tourniquet in reducing blood loss after total knee replacement: a randomized controlled trial

Background
The use of a pneumatic tourniquet in Total knee Arthroplasty (TKA) has always been a controversial issue with several reports of significant blood loss following TKA without tourniquet use that can sometimes require transfusion.
Purpose
To examine whether tourniquet use during TKA has reduced total measured blood loss, altered postoperative hemoglobin concentration and operative time, improved postoperative limb swelling, or decreased the postoperative pain and complication rate.
Methods
It is a single-center randomized controlled trial in which 90 patients, who underwent primary TKA and met the inclusion criteria, were enrolled with 45 patients were operated on with the use of pneumatic tourniquet and 45 patients without the use of tourniquet in a random allocation. Afterward, patients were assessed for total perioperative measured blood loss, operative time, postoperative limb swelling, postoperative pain, and complication.
Results
No statistically significant difference was found between the two groups regarding total perioperative measured blood loss (P=0.107), the need for blood transfusion (P=1), and the 6M walking test (P=0.324). However, there was a significant difference between patients with and without a tourniquet in terms of operating time with lower operative time with using tourniquet (P=0.007), hospital stay with shorter hospital stay in patients without tourniquet (P=0.023), postoperative knee pain visual analog scale with lower perception of pain in patients without tourniquet (P=<0.001), and modifications in limb circumference after 48 h with significantly less limb swelling in patients without tourniquet (P=<0.001).
Conclusion
The use of a tourniquet was associated with higher postoperative loss of blood, postoperative knee pain, lower limb swelling, and consequently a prolonged hospital stay, but it took a shorter operative time and was associated with lower intraoperative loss of blood. However, the total measured perioperative blood loss was the same without the need for blood transfusion in any group. Not using a tourniquet seems to be associated with a better functional outcome, less perception of pain and less swollen limb.