Comparison of Two Techniques of Locoregional Analgesia in Total Knee Prosthesis Surgery : Block to the Adductor Channel Versus Peri-articular Local Infiltrations

"The block at the adductor channel will be realized under echo guidance, before the spinal anesthesia, by puncture at the upper 1/3 of the thigh. It will be used echogenic needle adapted to the morphotype of each patient, of varying length from 50mm to 100mm. A single injection of 20mL of ROPIVACAINE 2mg / ml, the efficacy of which should be checked before spinal anesthesia is performed by a cold test.~Knee analgesia will be supplemented by per-operative infiltration of 50mL of ROPIVACAINE 2mg / ml at the posterior capsule, once the surfaces joints prepared to accommodate the prosthesis and by two placebo infiltrations of 50mL each of physiological saline in the medial and lateral ligaments and in the edges of the incision."

"A placebo injection to the adductor channel of 20 mL of physiological serum will be performed in the pre-induction room before surgery, according to the same procedures as the patients of the ACB group.~During the surgical procedure, patients in the ILA group will receive a total dose of 300mg of ROPIVACAINE 2mg / ml in the form of 3 periarticular injections. The first injection of 50mL of ROPIVACAINE 2mg / ml will be made once the articular surfaces are prepared to receive the prosthesis, at the level of the posterior capsule. The second injection of 50mL of ROPIVACAINE 2mg / ml will be performed once the total knee prosthesis is installed, in the medial and lateral ligaments. Finally, the last injection will also include 50mL of ROPIVACAINE 2mg / ml and will be made in the edges of the incision at the time of closure."