[Effectiveness of peri-articular infiltration with local anesthetic and adjuvants for post-surgical pain control in total knee replacement].

INTRODUCTION Total knee arthroplasty (TKA) is one of the most successful orthopedic treatments, however, it has been associated with severe postsurgical pain in 30-60% of patients. We propose that infiltration of the articular capsule of the knee during surgery will decrease postsurgical pain. MATERIAL AND METHODS Experimental, randomized, double-blind study in patients undergoing unilateral TKA between April 2018 and January 2019. Patients were divided into two groups, the first infiltration with placebo and the second with anesthetic solution and adjuvants (fentanyl, epinephrine and ketorolac). Pain was measured with the visual analog scale (VAS) at 4, 6, 8, 12, 18, 24, 36 and 48 hours postsurgical, as well as the consumption of opioid analgesics and antiemetics. RESULTS 20 patients in each group, with a follow-up of 4 weeks. There were no significant differences in demographic characteristics between the two groups. Better control of postsurgical pain was observed in the group that received infiltration with anesthetic and adjuvant, as well as a decrease in the consumption of opioid analgesics and antiemetics. There was no difference in bleeding or in the incidence of infections between the two groups. CONCLUSION Peri-capsular infiltration is a safe and effective method, as part of multimodal analgesia in total knee arthroplasty, as it decreases postsurgical pain, opioid and antiemetic use and does not increase postsurgical bleeding.