Continuous Adductor Canal Blocks Are Superior to Continuous Femoral Nerve Blocks in Promoting Early Ambulation After TKA

Abstract

Background Femoral continuous peripheral nerve blocks (CPNBs) provide effective analgesia after TKA but have been associated with quadriceps weakness and delayed ambulation. A promising alternative is adductor canal CPNB that delivers a primarily sensory blockade; however, the differential effects of these two techniques on functional outcomes after TKA are not well established. Questions/purposes We determined whether, after TKA, patients with adductor canal CPNB versus patients with femoral CPNB demonstrated (1) greater total ambulation distance on Postoperative Day (POD) 1 and 2 and (2) decreased daily opioid consumption, pain scores, and hospital length of stay.Methods Between October 2011 and October 2012, 180 patients underwent primary TKA at our practice site, of whom 93% (n = 168) had CPNBs. In this sequential series, the first 102 patients had femoral CPNBs, and the next 66 had adductor canal CPNBs. The change resulted from a modification to our clinical pathway, which involved only a change to the block. An evaluator not involved in the patients' care reviewed their medical records to record the parameters noted above. Results Ambulation distances were higher in the adductor canal group than in the femoral group on POD 1 (median [10 Conclusions Adductor canal CPNB may promote greater early postoperative ambulation compared to femoral CPNB after TKA without a reduction in analgesia. Future randomized studies are needed to validate our major findings. Level of Evidence Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

The adductor canal block provides effective analgesia similar to a femoral nerve block in patients undergoing total knee arthroplasty—a retrospective study

“…In the current study, patients in the ACB group were significantly better participants in postoperative physical therapy vs patients who received FNB. This finding is consistent with previous studies that have demonstrated ACB preserves quadriceps strength [15,26,27] and that ACB enhances ambulation compared with FNB [19,25]. Adductor canal block preserves motor function, resulting in improved physical therapy after TKA.…”

“…Most of the literature comparing ACB to FNB has primarily focused on preserving quadriceps strength and participation in physical therapy as the primary outcome. Mudumbai et al [25] compared a continuous ACB to a continuous FNB in patients undergoing TKA, but the primary outcome for this study was postoperative gait distance, which was found to be greater in patients who received an ACB. Similarly, Jaeger et al [26] performed a prospective study comparing continuous ACB to continuous FNB after TKA and found that patients in the ACB group had more preserved quadriceps strength.…”

The Spread of Ultrasound-Guided Injectate From the Adductor Canal to the Genicular Branch of the Posterior Obturator Nerve and the Popliteal Plexus

“…24 The midpoint of the thigh was proximal to the AC in all cadaver sides, similar to the findings by Bendtsen et al 7 and Wong et al 14 Several studies have made the claim that the midpoint of the thigh-defined as the midpoint between the ASIS and the base of the patella-is within the AC. 8,9,[25][26][27][28][29][30][31][32][33][34] Thus, studies comparing the analgesic efficiency of a femoral triangle block with a nerve block technique where the local anesthetic is injected into the AC proper should be interesting for future research.…”

Integrated Care Pathways in Total Hip and Knee Arthroplasty

“…Adductor canal block showed better quadriceps muscle postoperative strength with respect to the FNB and therefore may promote an earlier ambulation without a significant difference in postoperative pain [67][68][69].…”