Objective      To investigate the effect of 2 postoperative analgesia methods on blood coagulation in the patients after total knee arthroplasty (TKA) with thrombelastography (TEG).       Methods      Totally 60 patients (18 years old) scheduled for elective unilateral TKA (ASA Ⅰ～Ⅱ) in our department from December 2014 to May 2015 were enrolled in this study. They were randomly divided into continuous femoral nerve block (CFNB) group and patient-controlled intravenous analgesia (PCIA) group

with 30 cases in each group. Analgesia was maintained for 2 d. The visual analogue scale (VAS) scores were recorded at 6

12

24

and 48 h after surgery. The TEG parameters were measured at the time before anesthesia (T0)

the time when loosening the tourniquet (T1)

the end of surgery (T2)

and in 1 d (T3) and 2 d (T4) after operation. The VAS scores and TEG parameters at different times were compared between the 2 groups.       Results      The VAS scores were significantly lower after TKA at all time points in the CFNB group than the PCIA group (P0.05). Compared with T0 in CFNB group

the K values at T4 was significantly longer and the α-angle and MA values at T3 and T4 were significantly smaller (P0.05). However

in the PCIA group

the R and K values were significantly shorter and the α-angle and MA values were significantly bigger at T3 and T4 than those at T0 (P0.05). Compared with PCIA group at T3 and T4

the R and K values were significantly prolonged and the α-angle and MA values were significantly smaller in the CFNB group (P0.05).       Conclusion      The patients receiving CFNB after TKA have better pain relief than those of PCIA

and may improve their hypercoagulability.