Concentration Effect of Local Anesthetics on Femoral Nerve Block Efficiency

US-guided femoral nerve block is used effectively in post-operative pain management in the surgical treatment of the lower extremity. However, the volume and concentration of the local anesthetic drug to be administered remains controversial. In this prospective, randomized, double-blinded study, patients who underwent unilateral primary total knee arthroplasty and successfully performed spinal anesthesia with standard method and dosage, will be selected for US-guided femoral nerve block after the operation. Patients will be divided into three groups with simple randomization. The First group will be determined as the control group (GCont) and only dressing will be applied to the patients. For second group(G125), 0,125% 20 ml local anesthetic and for the third group (G25), 0,25% 10 ml local anesthetic will be administered to the femoral nerve without changing the drug dose (25 mg bupivacaine). Whether there is a difference between post-op analgesia durations, motor block formation, mobilization time and 90° flexion time between the groups will be investigated.