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. 2018 Sep 26;6(9):2325967118797990.
doi: 10.1177/2325967118797990. eCollection 2018 Sep.

Quadriceps Strength Deficits After a Femoral Nerve Block Versus Adductor Canal Block for Anterior Cruciate Ligament Reconstruction: A Prospective, Single-Blinded, Randomized Trial

Robert P Runner  1 , Stephanie A Boden  1 , William S Godfrey  1 , Ajay Premkumar  2 , Heather Samady  3 , Michael B Gottschalk  1 , John W Xerogeanes  1
Affiliations

Quadriceps Strength Deficits After a Femoral Nerve Block Versus Adductor Canal Block for Anterior Cruciate Ligament Reconstruction: A Prospective, Single-Blinded, Randomized Trial

Robert P Runner et al. Orthop J Sports Med. .

Abstract

Background: Peripheral nerve blocks, particularly femoral nerve blocks (FNBs), are commonly performed for anterior cruciate ligament (ACL) reconstruction. However, associated quadriceps muscle weakness after FNBs is well described and may occur for up to 6 months postoperatively. The adductor canal block (ACB) has emerged as a viable alternative to the FNB, theoretically causing less quadriceps weakness during the immediate postoperative period, as it bypasses the majority of the motor fibers of the femoral nerve that branch off proximal to the adductor canal.

Purpose/hypothesis: This study sought to identify if a difference in quadriceps strength exists after an ACB or FNB for ACL reconstruction beyond the immediate postoperative period. Beyond the immediate postoperative period, we anticipated no difference in quadriceps strength between patients who received ACBs or FNBs for ACL reconstruction.

Study design: Randomized controlled trial; Level of evidence, 1.

Methods: A total of 102 patients undergoing primary ACL reconstruction using a variety of graft types were enrolled between November 2015 and April 2016. All patients were randomized to receive an ACB or FNB before surgery, and the surgeon was blinded to the block type. All patients underwent aggressive rehabilitation without functional bracing postoperatively. The time to the first straight-leg raise was reported by the patient. Isokinetic strength testing was performed at 3 and 6 months postoperatively.

Results: Data for 73 patients were analyzed. There was no significant difference in patient demographics of age, body mass index, sex, or tourniquet time between the FNB (n = 35) and ACB (n = 38) groups. The mean time to the first straight-leg raise was similar, at 13.1 ± 1.0 hours for the FNB group and 15.5 ± 1.2 hours for the ACB group (P = .134). The mean extension torque at 60 deg/s increased significantly for both the ACB (53.7% ± 3.4% to 68.3% ± 2.9%; P = .008) and the FNB (53.3% ± 3.3% to 68.5% ± 4.1%; P = .006) groups from 3 to 6 months postoperatively. There was also no significant difference in mean extension torque at 60 deg/s or 180 deg/s between the FNB and ACB groups at 3 and 6 months. There were no significant differences in postoperative complications (infection, arthrofibrosis, retear) between groups.

Conclusion: Although prior studies have shown immediate postoperative benefits of ACBs compared with FNBs, with a faster return of quadriceps strength, in the current study there was no statistically or clinically significant difference in quadriceps strength at 3 and 6 months postoperatively in patients who received ACBs or FNBs for ACL reconstruction.

Keywords: ACL; adductor canal; anterior cruciate ligament reconstruction; lower extremity; nerve block; quadriceps strength.

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Conflict of interest statement

One or more of the authors has declared the following potential conflict of interest or source of funding: J.W.X. is a consultant for Arthrex, Mye-Eye, Linvatec, and VisionScope and has received educational support from Linvatec. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Figures

Figure 1.
Figure 1.
CONSORT (Consolidated Standards of Reporting Trials) flow diagram of patient enrollment, treatment allocation, and follow-up. ACB, adductor canal block; FNB, femoral nerve block.
Figure 2.
Figure 2.
Graph displaying overall significant improvement in mean extension torque at 60 deg/s at 3 and 6 months postoperatively for both the adductor canal block (ACB) and the femoral nerve block (FNB) groups.
Figure 3.
Figure 3.
Graph displaying no significant differences in mean extension torque at 60 deg/s or 180 deg/s between the adductor canal block (ACB) and femoral nerve block (FNB) groups at 3 and 6 months postoperatively.
See this image and copyright information in PMC

References

    1. Abdallah FW, Whelan DB, Chan VW, et al. Adductor canal block provides noninferior analgesia and superior quadriceps strength compared with femoral nerve block in anterior cruciate ligament reconstruction. Anesthesiology. 2016;124(5):1053–1064. - PubMed
    1. Cohen J. Statistical Power Analysis for the Behavioral Sciences. 2nd ed Hillsdale, New Jersey: Lawrence Earlbaum Associates; 1988.
    1. Dauri M, Fabbi E, Mariani P, et al. Continuous femoral nerve block provides superior analgesia compared with continuous intra-articular and wound infusion after anterior cruciate ligament reconstruction. Reg Anesth Pain Med. 2009;34(2):95–99. - PubMed
    1. Dauri M, Polzoni M, Fabbi E, et al. Comparison of epidural, continuous femoral block and intraarticular analgesia after anterior cruciate ligament reconstruction. Acta Anaesthesiol Scand. 2003;47(1):20–25. - PubMed
    1. Ebell MH, Siwek J, Weiss BD, et al. Strength of Recommendation Taxonomy (SORT): a patient-centered approach to grading evidence in the medical literature. J Am Board Fam Pract. 2004;17(1):59–67. - PubMed

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