Comparison of different local analgesia protocols in postoperative pain management after total knee arthroplasty

OBJECTIVES: This study was to compare the effects of different local analgesia protocols on osteoarthritis patients undergoing total knee arthroplasty (TKA). METHODS: Medical records of 148 osteoarthritis patients who underwent unilateral TKA between October 2016 and October 2017 in our hospital were retrospectively analyzed. All these patients were divided into three groups according to the pain management protocol (morphine, morphine + cocktail [100 mg ropivacaine, 10 mg morphine, and 30 mL 0.9% sodium chloride solution containing 2 mL betamethasone (4 mg)], or cocktail). The postoperative visual analog scale (VAS) score, muscle strength, and complications were compared between the groups. RESULTS: At 6 and 12 hours post-operation, the VAS score in group C was significantly higher than that in group A or group B. In addition, the muscle (quadriceps femoris) strength score of group C (3.7 ± 2.8) was significantly higher than that in groups A and B at 6 and 12 hours post-operation. The VAS score and muscle strength score showed no significant differences among the three groups at 24 and 36 hours post-operation. The time of postoperative first void of group C was significantly shorter than that of groups A and B. Groups A or B had a significantly higher incidence of nausea and emesis compared with group C. The incidence of pruritus was higher in groups A or B than that in group C. CONCLUSION: Epidural anesthesia combined with local analgesic cocktail injection is a preferable effective multimodal analgesia for TKA.