In the present study, TKA with IA-TXA plus drain clamping for 3 hours resulted in a significant blood loss reduction as compared with clamping for 2 hours or 30 minutes. No significant intergroup difference was observed for complication rates.
Blood loss is an important postoperative consideration that must be considered after TKA. Bleeding into soft tissues surrounding the knee increases pain, stiffness, and length of recovery following surgery.19 TXA application has recently become one of the most popular methods for reducing blood loss and transfusion requirements. TXA (tranexamic acid) is an antifibrinolytic agent and was discovered in 1962. It prevents the formation of plasmin, and thus inhibits the breakdown of fibrin clots and decreases bleeding. Although TXA has been administered intramuscularly, intravenously, and intraarticularly, it is being increasingly administered locally due to theoretically lower rates of systemic effects, including those related to thromboembolic disease. However, due to safety concerns regarding PTE, interest is growing interest in the use of TXA as an IA agent in TKR. In the present study, we decided to use IA-tranexamic acid to reduce blood loss after TKA.
IA-TXA with drain-clamping reduces blood loss in TKA as compared with IA-TXA without clamping. This method is considered effective for reducing bleeding by forming a tamponade before opening. Prior studies have examined many methods, such as the intermittent method and specific timed drain clamping after surgery to reduce blood loss postoperatively. However, no study has determined the optimum timing of drain clamp release after TKA with TXA. Liao et al.13 conducted a systematic review and meta-analysis on the efficacy of TXA plus drain-clamping in TKA and concluded that this technique reduced blood loss and the need for transfusion. However, the seven clinical studies8,20−25 included in their meta-analysis13 were conducted using different clamping times (from 1 to 3 hours) and TXA dosages (range 250 to 1000 mg). We tried to define an effective clamping time by injecting TXA at 3 g/30 cc + 70 cc of normal saline and found EBLs decreased and the percentage of patients with a drainage amount of < 300 mL increased as clamping time increased.
When clamping is released early, effective bleeding control cannot be achieved, that is, longer clamping times are required to form effective tamponades. Since the half-life of tranexamic acid is 3 hours, we examined the effects of clamping times up to 3 hours.26 Furthermore, it should be noted that complications such as hematoma can occur when clamping times are excessive (ca. > 4 hrs), as accumulations of blood in knee joints can lead to swelling, delayed wound healing, and increased risk of infection.11 We found no significant difference between the three groups in terms of complications such as DVT, superficial infections, and wound complications.
The cytotoxic effect of IA-TXA on cartilage should be considered when the surgical intention is to preserve native cartilage tissues; its cytotoxicity may not affect total joint arthroplasties involving removal of entire articular cartilage. Effective dosing for topical TXA ranges from 15 to 100 mg/ml. Increased exposure time to TXA at high concentrations is cytotoxic to cartilage. Because patients included in this study did not undergo patella resurfacing, we needed to minimize TXA exposure time and concentration on the articular surface, and thus, decided to use TXA at a concentration of 30 mg/ml and to limit the maximum exposure time to 3 hours.
The study has several limitations. First, a relatively small number of cases were included in each group because all operations were performed by one surgeon in a single center. Second, postoperative blood loss was low in some patients when the surgeon was able to well identify and cauterize bleeding vessels, though vessel bleeding was carefully cauterized in all cases. Third, individual bleeding tendencies differ, and numerous factors that influence blood loss should have been considered. However, given the size of our cohort, we included factors considered important and excluded factors that may have confounded results, such as a history of anticoagulant/antiplatelet medication, abnormal coagulation factors, and cases involving soft tissue release. Fourth, as blood loss could not be accurately measured, EBLs were calculated using Mercuriali’s and Nadler's formulae. However, Nadler's formula calculates blood volume based on weight and height, and thus, fluid-induced body changes preop to 5 days postop may have introduced errors. Despite these limitations, we believe our findings are meaningful as they provide evidence of the optimal duration of drain-clamp application after TKA with IA-TXA and provide a rationale how to minimize bleeding after TKA.