Yoeri Bemelmans

Local infiltration analgesia in knee arthroplasty 47 4 Introduction Early mobilization after TKA can be delayed due to severe high intense pain 3 to 6 h postoperative [6, 11]. Recent literature supports the use of LIA to challenge with direct postoperative pain after TKA [17]. LIA with ropivacaine in joint replacement surgery was first described in 2003 after which the technique was further developed [4, 19, 31]. The literature shows progressive results in terms of pain control, early mobilization and discharge fromhospital and reduced opiate use [1, 3, 11, 30, 31]. Several results are attribut- able to different analgesic infusion techniques after TKA, all with positive and negative side effects [11, 30]. This technique involves intra-operative infiltration of an analge-sic mixture. The combination of ropivacaine with adrena-line is most common used and described in the literature to deal with postoperative pain [17]. During surgery, the use of locally administered adrenaline reduces potentially toxic blood concentrations of ropivacaine [4, 6, 17, 22, 24], decreases the clearance and distribution processes into the blood flow [29], and it may also reduce the risk of bleeding into the knee [7]. However, there are also some potential local and systemic adverse effects such as tissue necrosis and increased risk of infections [12, 21, 22, 29, 30]. The data are limited to support the role of adrenaline during intra-operative single-shot LIA in combination with ropiv-acaine in patients undergoingTKA [17, 18, 23, 27, 28, 30, 34]. The theoretical advantage of adrenaline is the vaso-constrictive effect. On the other hand, ropivacaine itself is a long-acting analgesic with vasoconstrictive properties to reduce local absorption [4, 5, 22, 24]. There are no data to support the effect of ropivacaine alone for single-shot LIAon postoperative pain relief after TKAcomparedwithLIA, consisting a ropivacaine and adrenalinemixture. This study hypothesized that LIA with only ropivacaine is at least as effective in short terms as the widely used current method, LIA procedure with mixture of ropivacaine and adrenaline. This prospective, randomized, double-blind controlled trial examines the effect of adrenaline in the LIA mixture in patients undergoing TKA. Materials andmethods Fifty patients with a painful and disabled knee joint result-ing from osteoarthritis, a high need to obtain pain relief and improve function, able and willing to follow instruc- tions were included after informed consent. Patients with a general or an active knee infection, failure of previous joint replacement of the knee to be operated on, pregnancy, con-traindication for ropivacaine and/or adrenaline, and patients who were not able to understand and complete the proce-dure due to cognitive dysfunction or language barrier were not included in this pilot study.