Purpose: In most studies, local infiltration analgesia (LIA) can provide better analgesic effect in the early postoperative period, but the optimal technique is unknown. Our study was designed to evaluated the early clinical efficacy and safety of periarticular analgesia versus intraarticular injection in Total knee arthroplasty (TKA). Design: A prospective study was conducted on 100 patients admitted for TKA. Subjects were divided into two groups: 50 in group A, 50 in Group B. Methods: Patients in group A received periarticular analgesia with ropivacaine 300 mg and morphine 5 mg (the drugs were diluted with saline to 50 ml) in the periosteal borders, posterior capsule and extensor apparatus and subcutaneous tissues during surgery. After stitching of joint capsule, tranexamic acid (TXA) 2 g (20 ml) was injected into the articular cavity. Group B patients had all of the 70 mL mixture (ropivacaine 300 mg, morphine 5 mg and TXA 2 g) injected intraarticularly after stitching of the joint capsule. We assessed postoperative length of stay (LOS), knee functional outcome, pain, and complications after surgery. Findings: There was no statistical difference in visual analog scale (VAS) scores for knee pain between the two groups on postoperative day (POD)1, 3, or 30 (P >.05). Mean postoperative LOS was 7.40 1.98 days in Group A, compared to 8.02 2.09 days in Group B (P >.05). No significant differences between groups were seen in the mean swelling ratio (P >.05), and no significant differences were found in the Hospital for Special Surgery (HSS) knee score and range of motion (ROM) at 30 days follow-up (P >.05). There was also no statistical difference in the incidence of complications (such as superficial wound infection, deep vein thrombosis (DVT) and nausea and vomiting) between the Group A and the Group B. Conclusions: In conclusion, it seems that intraarticular injection had a similar analgesic effect compared with periarticular injection when adopting a multi-modal analgesia regimen. Our results suggest that there is no obvious advantage with the use of periarticular injections compared to intraarticular injection. The authors believe that intraarticular injection may be a better technique compared with periarticular injections in the absence of a drainage tube because intraarticular injection can reduce the number of surgical steps and have similar postoperative outcomes. (c) 2022 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.