We identified a total of 189 citations as potentially relevant. By screening the title and reading the abstract and the entire article, we found that three RCTs and two non-RCTs enrolling a total of 766 knees at a final follow-up were eligible for data extraction and meta-analysis [
9]-[
13]. The patients' characteristics were presented in Table
1. The sample size for each study ranged from 20 to 349. Jadad scale is used to evaluate the quality of RCTs while MINORS assessment is used for non-RCTs. The quality of the literature is relatively high. But there are still some methodological limitations in RCTs. All the RCTs [
9]-[
11] reported that randomization was conducted through a computer-assisted program. A double-blind methodology was reported in two RCTs [
10],[
11]. None of the RCTs suggest a methodology for the blinding assessors. All of the studies provided results for a minimum of 95% of the included patients. Most of the patients who managed to undergo primary TKA suffered from osteoarthritis. Kim and Comadoll [
11],[
13] reported that all TKA were accomplished by the same doctor. Cemented prosthesis was used in four studies [
10]-[
13]. The other one used an uncemented prosthesis. Electrocautery hemostasis combined with a thrombin-based hemostatic agent was used in the treatment group in all the studies except one [
12] which used an agent only. The control group received electrocautery hemostasis. Four literatures [
9]-[
12] mentioned volume of drainage in 24 h postoperatively. None of the studies reported whether drainage was clamped or not, while two studies [
10],[
11] stated the size and number of the drainage tube. Tourniquets were used in all the inclusive patients and were deflated after wound closure in three studies [
9]-[
11] and before wound closure in Comadoll's study. Helito did not provide this information while the pressure of the tourniquet was recorded (300 mmHg) [
12]. Two studies [
10],[
11] applied bandage after wound closure. Spinal anesthesia was performed in the study of Kim and Helito [
11],[
12]. Others did not mention an anesthesia method. The dosage of Floseal® ranged from 10 to 20 ml, 10 ml in three studies [
9]-[
11] and 20 ml in Comadoll's trial. None of the studies used placebo in a control group. Four studies [
9],[
10],[
12],[
13] provided the indications of blood transfusion, which based on postoperative hemoglobin level, signs and symptoms of anemia such as hypotension, paleness, and tachycardia. Perioperative antithromboembolic prophylaxis therapy was performed in all the patients as followed in Table
1. The duration of a follow-up ranged from discharge to 6 weeks.
Table 1
Cohort characteristics
| 97/99 | 72.7/70.1 | NS | 10 | Aspirin or warfarin, NS | RCT | 6 |
| 51/42 | 67.9/70.2 | 24/17 | 10 | LMWH 4,000 IU | RCT | 4 |
| 56/52 | 65.9/65.1 | 20/21 | 10 | Enoxaparin, NS | RCT | 6 |
| 10/10 | 67.8/66.6 | NS | NS | Enoxaparin 40 mg | PCT | 17 |
| 184/165 | NS | 64/54 | 20 | Warfarin 5 mg | CCT | 18 |