[Progress of injection sites of local infiltration analgesia in total knee arthroplasty].

Objective: To review the research progress of injection sites of local infiltration analgesia (LIA) in total knee arthroplasty (TKA). Methods: The relevant domestic and foreign literature in recent years was extensively reviewed. The neuroanatomy of the knee, and the research progress of the selection and the difference of effectiveness between different injection sites of LIA in clinical studies were summarized. Results: Large concentrations of nociceptors are present throughout the various tissues of the knee joint. Patellar tendon, subpatellar fat pad, lateral collateral ligament insertions, iliotibial band insertions, suprapatellar capsule, and posterior capsule were more sensitive to pain. Most current studies support injections into the lateral capsule, collateral ligament, retinaculum, quadriceps tendon, fat pad, and subcutaneous tissue. Whether to inject into the back of the knee and subperiosteum is controversial. Conclusion: The relative difference of knee tissue sensitivity to pain has guiding significance for the selection of LIA injection site after TKA. Although researchers have conducted clinical trials on injection site and technique of LIA in TKA, there are certain limitations. The optimal scheme has not been determined yet, and further studies are needed.