Background: Some surgeons release the tourniquet before closing the
wound to secure hemostasis during knee arthroplasty. We examined whether early
tourniquet release could reduce the perioperative blood loss and whether not
releasing the tourniquet until after wound closure would increase the risk of
early postoperative complications.
Methods:We searched electronic databases and reference lists of
relevant articles, retrieved all of the published randomized controlled trials
designed to address these issues, and performed a meta-analysis.
Results:Eleven studies involving a total of 872 patients and 893
primary knee arthroplasties were analyzed systematically. The studies showed
considerable clinical and methodological diversity. Early release of the
tourniquet increased the total measured blood loss (weighted mean difference =
228.7 mL; 95% confidence interval = 168.3 to 289.1; p < 0.00001). Early
release also increased blood loss as calculated on the basis of the maximum
decrease in hemoglobin concentration (weighted mean difference = 320.7 mL; 95%
confidence interval = 204.3 to 437.1; p < 0.00001). The rate of
reoperations due to postoperative complications was 3.1% (nine of 290) in the
group with late tourniquet release compared with 0.3% (one of 290) in the
group with early tourniquet release; the risk difference was 3% (95%
confidence interval, 0.1% to 5%), which was significant (p = 0.04).
Conclusions: Early tourniquet release for hemostasis increases the
blood loss associated with primary knee arthroplasty. However, tourniquet
release after wound closure can increase the risk of early postoperative
complications requiring another operation. Well-conducted large studies are
needed to further explore the risk of early postoperative complications
associated with late tourniquet release in knee arthroplasty.
Level of Evidence: Therapeutic Level II. See Instructions
to Authors for a complete description of levels of evidence.