Effect of Adductor Canal Nerve Block Compared to a Simulated Block on Quadriceps Strength Following Knee Arthroplasty

A 18 Gauge Tuohy needle will be inserted and its position will be confirmed using ultrasound guidance. Once the adequacy of the position is confirmed, the anesthesiologist will administer 15 mL of bupivacaine 0.25% with epinephrine in divided doses and examine the quality of its spread. A 20 Gauge polyamide catheter will be inserted at 2 cm in the space. The needle will then be withdrawn and the catheter will be fixed in place. Three mL of the same mixture of local anesthetics will be administered through the catheter and the anesthesiologist will observe the quality of its distribution. Bupivacaine 0.125% will be administered through the catheter using an infusion pump for 48 hours. Knee extensor muscle strength, pain and side-effects will be assessed at different time-points.

The insertion of the Tuohy needle and the injection of 15 mL of bupivacaine 0.25% with epinephrine will be simulated. The insertion of the polyamide catheter, the withdrawal of the needle and the injection of local anesthetics through the catheter will also be simulated. The infusion of bupivacaine 0.125% will also be simulated for 48 hours. Knee extensor muscle strength, pain and side-effects will be assessed at different time-points.