Patients were randomly allocated to receive either an ACB followed by catheter placement (n=20) or an adductor canal block followed by sham catheter placement (n=20). The sham catheter was placed on the surface of the leg and covered by an opaque dressing to conceal the insertion site. (A similar dressing was placed on real catheter insertions to conceal group assignment from both patient and assessor.) All patients had the proximal end of their catheter attached to a Pajunk 350 ml FuserPump (FuserPumps are portable elastomeric infusion pumps) concealed in opaque bags to prevent patients and assessors from determining which pumps were actually functioning. These pumps function without a motor and so make no sound. Computer generated randomization was performed for patient group assignment at the time of enrolment in the study. Randomization assignments were done in blocks of 10 in a 1:1 ratio with assignments placed in sealed numbered opaque envelopes. Only the anesthesiologist responsible for performing the block was aware of the group to which a given patient was assigned. The researchers responsible for data collection were unaware of the group to which each patient was assigned .