Intravenous tranexamic acid (TXA) has been shown
to be effective in reducing blood loss and the need for transfusion
after joint replacement. Recently, there has been interest in applying
it topically before the closure of surgical wounds. This has the
advantages of ease of application, maximum concentration at the
site of bleeding, minimising its systemic absorption and, consequently,
concerns about possible side-effects. We conducted a systematic review and meta-analysis which included
14 randomised controlled trials (11 in knee replacement, two in
hip replacement and one in both) which investigated the effect of
topical TXA on blood loss and rates of transfusion. Topical TXA
significantly reduced the rate of blood transfusion (total knee
replacement: risk ratio (RR) 4.51; 95% confidence interval (CI):
3.02 to 6.72; p <
0.001 (nine trials, I2 = 0%); total
hip replacement: RR 2.56; 95% CI: 1.32 to 4.97, p = 0.004 (one trial)).
The rate of thromboembolic events with topical TXA were similar
to those found with a placebo. Indirect comparison of placebo-controlled
trials of topical and intravenous TXA indicates that topical administration
is superior to the intravenous route. In conclusion, topical TXA is an effective and safe method of
reducing the need for blood transfusion after total knee and hip
replacement. Further research is required to find its optimum dose
for topical use. Cite this article:
We conducted a systematic review and meta-analysis
of randomised controlled trials evaluating the effect of tranexamic
acid (TXA) upon blood loss and transfusion in primary total knee
replacement. The review used the generic evaluation tool designed
by the Cochrane Bone, Joint and Muscle Trauma Group. A total of
19 trials were eligible: 18 used intravenous administration, one
also evaluated oral dosing and one trial evaluated topical use.
TXA led to a significant reduction in the proportion of patients
requiring blood transfusion (risk ratio (RR) 2.56, 95% confidence
interval (CI) 2.1 to 3.1, p <
0.001; heterogeneity I2 =
75%; 14 trials, 824 patients). Using TXA also reduced total blood
loss by a mean of 591 ml (95% CI 536 to 647, p <
0.001; I2 =
78%; nine trials, 763 patients). The clinical interpretation of
these findings is limited by substantial heterogeneity. However,
subgroup analysis of high-dose (>
4 g) TXA showed a plausible consistent
reduction in blood transfusion requirements (RR 5.33; 95% CI 2.44
to 11.65, p <
0.001; I2 = 0%), a finding that should
be confirmed by a further well-designed trial. The current evidence
from trials does not support an increased risk of deep-vein thrombosis
(13 trials, 801 patients) or pulmonary embolism (18 trials, 971
patients) due to TXA administration.