Analgesic Effects of Different Local Infiltration Anesthesia Techniques Combined with Femoral Nerve Block in Patients Undergoing Total Knee Arthroplasty: A Randomized Controlled Clinical Trial.

Objective: Pain after total knee arthroplasty (TKA) remains an unresolved problem. Femoral nerve block (FNB) could relieve pain; however, it alone is insufficient. The local infiltration anesthesia technique (LIA) has been suggested as a supplement to FNB. This study aimed to evaluate the analgesic effects of different LIA combined with FNB in TKA patients. Methods: The femoral nerve was blocked with 0.375% ropivacaine 20mL, and all patients routinely received general anesthesia. The primary indicator was the proportion of patients who did not receive post-operative remedial analgesia. Seventy-eight patients were randomly assigned to PAI (periarticular injection combined with FNB), IAI (intra-articular injection combined with FNB), or control (FNB alone) groups. All patients underwent FNB under general anesthesia. The primary outcome was the proportion of patients who did not receive additional postoperative analgesia within the first 48 h after surgery. Results: Compared with the PAI and control groups, the IAI group had a higher proportion (69.23%) of patients who did not receive remedial analgesia within 48 hours after surgery ( Conclusion: When combined with FNB, intra-articular injection offers a superior analgesic effect and favorable recovery compared to periarticular injection and separate application of FNB.