Evaluation of the Analgesic Benefit of Adding the Blocks of the Intermediate and Medial Femoral Cutaneous Nerves in Addition to the Femoral Triangle Block for Postoperative Analgesia After a Knee Replacement Surgery

"This intervention was selected because it has the potential to optimize analgesia by skin coverage of the upper third of the surgical incision. The intervention will be performed as follows:~* The intermediate femoral cutaneous nerve will be visualized at the supralateral level of the sartorius muscle, in a duplicature of the fascia lata.~* The needle will be inserted at the same puncture site as for the femoral triangle block, with a latero-medial orientation in the plane (intracanalar compartment).~* In addition to the injection performed in the femoral triangle, two injections of 5 mL of 0.5% ropivacaine + epi 1:400 000 will be performed in addition, below the sartorius muscle (subsartorial compartment) and above the sartorius muscle (suprasartorial compartment)."

"* The high frequency linear ultrasound probe will be positioned midway between the superior edge of the patella and the anterosuperior iliac spine. It will then be moved to visualize the apex of the femoral triangle, confirmed by visualization of the sartorius muscle laterally and the long adductor medially.~* The needle will be inserted with a latero-medial orientation in the plane.~* The initial injection will be a single injection of 15 ml of 0.5% ropivacaine + epi 1:400 000 under the sartorius muscle, lateral to the femoral artery, at the level of the apex of the femoral triangle."

It will be performed in order to block the sensory branches of the innervation posterior to the knee with 15 ml of ropivacaine 0.3% + epi 1:400 000.