A Comparison of Sartorius Vs. Quadriceps Evoked Motor Response for Femoral Nerve to Prevent Secondary Catheter Failure

Objective: Continuous nerve block (freezing the nerve) is needed for knee replacement surgery to reduce pain, increase rehabilitation and discharge patients home fast. A lot of time, money and hospital resources are invested in inserting these catheters. The aim of this study is to compare two end points used for insertion of continuous femoral nerve block and to see which one results in fewer failures on the surgical ward. Methodology: Patients having total knee replacement surgery will be recruited in this study. Patients will be randomized into two groups. The continuous femoral nerve block catheter will be inserted using ultrasound and nerve stimulation with two different end points (certain muscle contraction). Patients will be followed on day 1 and 2 after surgery to observe which catheter fails, how much pain the patient suffers and how much painkiller the patients used.