Purpose: TKR is a frequent surgical procedure with significant post-operative pain, requiring lot of opiates. Side effects are frequent and can modify post-operative rehabilitation. The goal of the study is to determine if the adjunction to a femoral block of intra-articular ropivacaïne can diminish the use of opiates and then gives better clinical results. The main clinical outcome is the opiate consumption at 48 h.

Method: 80 consecutive patients admitted for TKR were randomized in the 2 groups (ropivacaïne vs control), surgeon, patient and clinical evaluator are blinded. Femoral block was performed and controlled for efficacy before surgery. Intra-articular injection of ropivacaïne or saline was delivered prior to wound closure with a catheter. Opiates were delivered with an ACP for 48 h. Rehabilitation was the same in the 2 groups.

Results: We found no differences between the 2 groups in the opiate consumption at 24 and 48 h (p> 0,5). There was even an increase in opiate use in the experimental group, that couldn’t be explained by other factors (age, weight, surgical time, surgical tourniquet time, sex). There was no differences in ROM, hospital stay, side effects and EVA.

Conclusion: There is no indication for the adjunction of intra-articular ropivacaïne to a femoral block after TKR. Other issues as combined blocks or other types of infiltrations (posterior capsule for example) could be considered in new trials to diminish pain after TKR.