This study is aimed to determine the efficacy and the safety of the tourniquet reinflation after early tourniquet release in total knee arthroplasty, compared to the method of early deflation without reinflation. The investigators hypothesized that the reinflation after early release of the tourniquet would be effective in terms of improved visualization of the surgical field and decreased operation time and blood loss, whereas it would increase tourniquet-related complication due to longer tourniquet-use time.

Total knee arthroplasty(TKA) is mostly performed with tourniquet applied, because it allows decreased intraoperative blood loss, better visualization of surgical field and better cement fixation of the implants, compared to the TKA without using tourniquet. However, there remains a controversy about the timing of tourniquet release, so the tourniquet may be unreleased throughout the whole operation time or released early just after cement fixation of the implants, atc. Early tourniquet release is generally aimed to control hidden arterial bleeding which would not be revealed if the tourniquet was unreleased. This method was reported to reduce arterial bleeding and its related complications, but it was also known that increase intraoperative bleeding, incidence of transfusion, and operation time. On the other hand, late tourniquet release, which the tourniquet is unreleased until the wound is closed, is reported to increase tourniquet-use time and related complications owing to longer tourniquet time, although it gives shorter operation time. The investigators have been used a way of reinflation of tourniquet after early release, once the arterial bleeding was controlled sufficiently, to balance the advantages and disadvantages of the early tourniquet release. The investigators were able to control arterial bleeding during the time the tourniquet was released, and the remained procedures were performed conveniently with good visualization of the surgical field after the tourniquet was reinflated again. However, there was no previous studies about the efficacy and the safety of the way of reinflation after early release of the tourniquet in the literature. Therefore, the investigators ask in this study whether the reinflation after early tourniquet release has advantages over the method of early tourniquet release without reinflation, in terms of efficacy and safety.

Inclusion Criteria:

• Diagnosis of primary osteoarthritis of the knee
• Scheduled for elective total knee arthroplasty
• Written signed consent

Exclusion Criteria:

• Revision TKA
• Diagnosis other than primary osteoarthritis
• Intra-articular indwelling drainage
• Refusing participate