Adductor Canal Block versus Femoral Nerve Block for Total Knee Arthroplasty: A Prospective, Randomized, Controlled Trial

• Published in: Anesthesiology (Philadelphia) Vol. 120; no. 3; pp. 540 - 550
• Main Authors: Kim, David H, Lin, Yi, Goytizolo, Enrique A, Kahn, Richard L, Maalouf, Daniel B, Manohar, Asha, Patt, Minda L, Goon, Amanda K, Lee, Yuo-yu, Ma, Yan, YaDeau, Jacques T
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD American Society of Anesthesiologists, Inc 01-03-2014; Lippincott Williams & Wilkins
• Subjects: Aged; Analgesia, Patient-Controlled - methods; Analgesics, Opioid - therapeutic use; Anesthesia; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Anesthetics, Local - administration & dosage; Arthroplasty, Replacement, Knee; Biological and medical sciences; Bupivacaine - administration & dosage; Double-Blind Method; Female; Femoral Nerve - drug effects; Humans; Hydromorphone - therapeutic use; Male; Medical sciences; Muscle Weakness - chemically induced; Nerve Block - methods; Oxycodone - therapeutic use; Pain Measurement - methods; Pain, Postoperative - drug therapy; Postoperative Complications - chemically induced; Prospective Studies; Quadriceps Muscle - drug effects; Treatment Outcome; Knee; Prospective; Femoral nerve; Randomization; Prosthesis; Anesthesia; Block; Clinical trial; Randomized controlled trial; Comparative study
• ISSN: 0003-3022; 1528-1175
• DOI: 10.1097/ALN.0000000000000119

BACKGROUND:This prospective double-blinded, randomized controlled trial compared adductor canal block (ACB) with femoral nerve block (FNB) in patients undergoing total knee arthroplasty. The authors hypothesized that ACB, compared with FNB, would exhibit less quadriceps weakness and demonstrate noninferior pain score and opioid consumption at 6 to 8 h postanesthesia.
METHODS:Patients received an ACB or FNB as a component of a multimodal analgesic. Quadriceps strength, pain score, and opioid consumption were assessed on both legs preoperatively and at 6 to 8, 24, and 48 h postanesthesia administration. In a joint hypothesis test, noninferiority was first evaluated on the primary outcomes of strength, pain score, and opioid consumption at 6 to 8 h; superiority on each outcome at 6 to 8 h was then assessed only if noninferiority was established.
RESULTS:Forty-six patients received ACB; 47 patients received FNB. At 6 to 8 h postanesthesia, ACB patients had significantly higher median dynamometer readings versus FNB patients (median [interquartile range], 6.1 kgf [3.5, 10.9] (ACB) vs. 0 kgf [0.0, 3.9] (FNB); P < 0.0001), but was not inferior to FNB with regard to Numeric Rating Scale pain scores (1.0 [0.0, 3.5] ACB vs. 0.0 [0.0, 1.0] FNB; P = 0.019), or to opioid consumption (32.2 [22.4, 47.5] ACB vs. 26.6 [19.6, 49.0]; P = 0.0115). At 24 and 48 h postanesthesia, there was no significant statistical difference in dynamometer results, pain scores, or opioid use between the two groups.
CONCLUSION:At 6 to 8 h postanesthesia, the ACB, compared with the FNB, exhibited early relative sparing of quadriceps strength and was not inferior in both providing analgesia or opioid intake.