Clamping drainage is unnecessary after minimally invasive total knee arthroplasty in patients with tranexamic acid

BACKGROUND Drainage and tranexamic acid (TXA) have been widely used in total knee arthroplasty (TKA). However, it remains unclear whether it is necessary to clamp the drain after minimally invasive TKA (MIS-TKA) when TXA is used. We therefore conducted a randomized controlled trial to compare the effects of clamping versus not clamping drainage following MIS-TKA in patients in whom TXA was used. METHODS From January 2015 to December 2015, 121 patients undergoing unilateral primary MIS-TKA were enrolled and randomly divided into 2 groups. In the clamping group (N = 60), drainage was clamped for the 1st 4 postoperative hours. In the nonclamping group (N = 61), drainage was not clamped. All patients underwent a minimidvastus approach and received 10 mg/kg TXA intravenously before tourniquet deflation. We recorded the total blood loss, drainage volume, and transfusion requirements in the postoperative period. We also measured the hemoglobin (Hb) and hematocrit (Hct) levels on postoperative days 1, 3, and 5. Other factors, including range of motion (ROM), visual analog scale (VAS), and occurrence of wound-related complications, deep vein thrombosis (DVT), and pulmonary embolism (PE) were recorded at the time of discharge and 1 and 6 months postoperatively. No statistically significant differences were found between the 2 groups with regard to age, gender, weight, BMI, preoperative Hb and Hct levels, preoperative ROM, VAS, duration of surgery, anesthesia method, and the American Society of Anesthesiologists classification. RESULTS The clamping group experienced better drainage volume results than the nonclamping group (P < 0.001). There were no statistically significant differences in TBL and transfusion requirements (P = 0.105 and 0.276, respectively); Hb and Hct levels on postoperative days 1, 3, and 5 were similar between the 2 groups. No significant differences were found for ROM, VAS, DVT, PE, wound-related complications, and hospital length of stay in the postoperative follow-up. CONCLUSION Based on our findings, clamping drainage is unnecessary after routine MIS-TKA using TXA.