Abstract: Objective To investigate the effect of ulinastatin (Urinary Trypsin Inhibitor, UTI) on patients’ perioperative inflammatory response, postoperative acute and chronic pain, and the rehabilitation of knee joint after bilateral total knee arthroplasty (TKA) under pneumatic tourniquet. Methods 40 patients scheduled for bilateral TKA under thigh tourniquet, were enrolled and randomly assigned to trial group (U group) and control group (C group). U group received intravenous ulinastatin and C group received saline at identical time points. All patients received the same general anesthesia, postoperative analgesia and rehabilitation protocols. The plasma concentration of inflammatory cytokines, such as IL-6, TNF-α, and IL-10, were recorded at different time points. The patient's VAS at rest and activity, the opioid consumption, the range of active knee flexion and continuous passive motion, and the time of walking 30 meters were observed and compared. Results No significant differences were found between two groups regarding the demographic data. The inflammatory response of U group was lower than C group. The VAS at rest and activity and sufentanil consumption at 4 hours after the surgery of U group were significantly lower than C group. No statistically significant difference was found in postoperative functional rehabilitation parameters at all time points. Conclusions Ulinastatin can alleviate perioperative inflammatory response, decrease early postoperative resting pain scores and reduce opioid consumption.

Key words: total knee arthroplasty, ulinastatin, inflammatory response, postoperative acute pain, rehabilitation.