Comparison between effects of adductor canal block and femoral nerve block on early postoperative course in total knee arthroplasty: a prospective double-blind, randomized controlled study

Context Femoral nerve block ( FNB) provides effective analgesia after total knee arthroplasty ( TKA) but has been associated with delayed ambulation due to quadriceps muscle weakness. Adductor canal block ( ACB) may be a promising alternative, with less effect on the quadriceps muscle and comparable analgesic efficacy. Aim The aim of the study was to compare ACB with FNB regarding the quadriceps muscle strength and its analgesic efficacy in patients following TKA. Settings and design This was a prospective, randomized, controlled, double-blinded study. Patients and methods The patients were randomized to receive either ACB or FNB. The primary outcome was the effect on quadriceps muscle and early ambulation as determined by the timed up and go test and 10-min walk test. The secondary outcome was to compare the analgesic efficacy as determined by numeric rating scale, opioid consumption, and hospital length of stay. Results We enrolled 110 patients, of whom 107 were analyzed. The timed up and go test and the 10-m walk test were significantly shorter in the ACB group than in the FNB group on the postoperative day 1 with P-value of 0.002 and 0.005, respectively, whereas the difference between both study groups was statistically nonsignificant on the postoperative day 2. There was no significant difference between the study groups regarding the numeric rating scale, morphine consumption, or length of stay. Conclusion ACB may promote early ambulation after TKA without a reduction in analgesia when compared with FNB.