Ultrasound Guided Obturator versus Sciatic Nerve Block in Addition to Continuous Femoral Nerve Block for Analgesia after Total Knee Arthroplasty

Abstract

Both obturator and sciatic nerve block in combination with femoral nerve block (FNB) have been suggested to be useful in relieving pain after total knee arthroplasty (TKA), compared with FNB alone. We compared their efficacy in this retrospective study. For six consecutive months, patients undergoing unilateral TKA under general anesthesia with continuous FNB plus obturator nerve block (n = 8) or continuous FNB plus sciatic nerve block (n = 8) were investigated. Knee pain was assessed using visual analogue scale (VAS) on the day of surgery and on postoperative days one to three. In addition, we also investigated intraoperative and postoperative morphine consumption. VAS scores and total morphine consumption were not different between the two groups, although patients in the FNB plus sciatic nerve block group were administered less morphine during surgery. Sciatic nerve block with continuous FNB may be superior to obturator nerve block with continuous FNB for analgesia during surgery for TKA.

Continuous Versus Single-Injection Sciatic Nerve Block Added to Continuous Femoral Nerve Block for Analgesia After Total Knee Arthroplasty

“…11 Thus, an equally divided sample of 50 was deemed sufficient for detection of a 50% reduction in morphine usage, with a 2-sided type 1 error of 5% and a power of at least 80%. A target sample size of 60 was established to increase the power.…”

The Analgesic Effect of Obturator Nerve Block Added to a Femoral Triangle Block After Total Knee Arthroplasty

“…The total intravenous morphine consumption during the first 24 postoperative hours was 2 mg (interquartile range [IQR], 0-15) in the combined ONB and FTB group, 20 mg (IQR, [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] in the FTB group (P = 0.0007), and 17 mg (IQR, in the LIA group (P = 0.002). The combined ONB and FTB group displayed reduced pain, nausea, and vomiting compared with the other groups.…”

“…[5][6][7] Pain and opioid consumption after TKA apparently can be reduced by adding obturator nerve block (ONB) to an FNB. [8][9][10] The analgesic effect of ONB and FTB, as part of a multimodal analgesia regimen after TKA, has not been tested previously.…”

Buprenorphine Added to Bupivacaine Prolongs Femoral Nerve Block Duration and Improves Analgesia in Patients Undergoing Primary Total Knee Arthroplasty—A Randomised Prospective Double-Blind Study

“…However, combined femoral/tibial nerve anaesthesia helped to avoid peroneal nerve anaesthesia, which presents as paralysis of the muscles of the anterior shin compartment and foot drop. A Japanese study [29] found no statistically significant differences in post-operative pain intensity and morphine consumption following combined femoral/sciatic vs. femoral/obturator nerve anaesthesia. However, that study involved smaller groups (8 patients in each).…”