High-dose local infiltration analgesia after hip and knee replacement—what is it, why does it work, and what are the future challenges?

In this issue of Acta Orthopaedica, 3 more randomized studies and results of the technique are presented. In a study on knee arthroplasty, Toftdahl et al. (2007) have compared the Local Infiltration Analgesia (LIA) technique to continuous femoral block. They found a significant reduction of opioid consumption and less pain during physiotherapy in the group receiving intraarticular infiltration. They also noted improved walking ability and better quadriceps function in the same group. Even though this study has some limitations (no blinding of patients, uneven distribution of NSAIDs), the authors conclude that the technique of local infiltration provides good analgesia after knee arthoplasty without increased risk. They also emphasize the need for further studies to optimize the technique.

Andersen and colleagues (2007a) have performed a study on this technique in hip arthroplasty, comparing LIA to continuous epidural infusion. Also in this study, the results are in favor of the local infiltration technique. Once again, it was found that narcotic consumption was significantly reduced. Pain relief at rest was good, but similar in the two groups in the immediate postoperative period, and significantly reduced in the LIA group from the second day when active treatment had ended. Furthermore, side effects were significantly lower due to avoidance of epidural analgesia, walking ability was better, and the hospital stay was reduced by 2 days in the LIA group. The authors conclude that this technique can be recommended for hip arthroplasty.

In a randomized, double-blinded, placebo-con-trolled study from Odense University Hospital (Andersen et al. 2007b) local infiltration analgesia was used in hip arthroplasty and compared to a control group receiving pure saline solutions. The patients treated with LIA experienced less pain up to 2 weeks postoperatively. They needed less additional analgesics and were more satisfied. Interestingly, this treatment regimen also resulted in less joint stiffness and better function 1 week postoperatively.