Continuous adductor-canal-blockade for adjuvant post-operative analgesia after major knee surgery: preliminary results

Abstract

Because both the saphenous nerve and in part the obturator nerve are traversing the adductor canal of the thigh, we hypothesised that repeated administration of a local anaesthetic (LA) into this aponeurotic space could be a useful option for post-operative analgesia after knee replacement surgery. A systematic search of the literature pertinent to the blockade of the saphenous and/or obturator nerves for pain relief after knee surgery was conducted. Further, pain and opioid requirements were evaluated in eight patients receiving a continuous blockade of the saphenous and obturator nerve (adductor-canal-blockade) after total knee arthroplasty (TKA). Finally, we performed cross-sectional MR scans of the adductor canal after injection of ropivacaine 30ml in one patient. The systematic literature search revealed only one controlled study, where selective blockade of the saphenous nerve was investigated for the purpose of clinical pain relief after knee arthroscopy. We located no studies reporting on saphenous and/or obturator nerve block for pain relief after TKA. Preliminary findings in eight patients demonstrated that a continuous adductor-canal-blockade for 48h after TKA was associated with low mean pain scores at rest and low mean requirements for supplemental morphine. MR scans in one patient demonstrated that 30ml of LA filled the adductor canal, including the distal part, where the posterior branch of the obturator nerve joins the vessels and the saphenous nerve. Continuous adductor-canal-blockade may be a valuable adjunct for post-operative analgesia after major knee surgery. These preliminary results should be confirmed in randomised, controlled trials.

Ultrasound-guided adductor canal block for arthroscopic medial meniscectomy: a randomized, double-blind trial

“…The primary benefit of an adductor canal block is to provide analgesia while limiting loss of quadriceps strength, presumably by blocking only the saphenous nerve, the nerve to the vastus medialis, and potentially the articular contribution of the obturator nerve to the knee joint. [10][11][12] We did not objectively measure quadriceps strength due to the outpatient nature of the primary surgical procedure. Indirectly, all patients were able to stand in the PACU, and no study participant mentioned subjective leg weakness or reported falls at the 24-hr follow-up interview.…”

“…9 The adductor canal block may provide superior analgesia over traditional distal saphenous nerve blocks for surgical procedures of the knee because this block includes the saphenous nerve, the nerve to the vastus medialis, and potentially the articular contribution of the obturator nerve to the knee joint. [10][11][12][13] Our primary hypothesis was that performing an adductor canal block as part of a multimodal analgesic regimen would result in improved analgesia immediately following arthroscopic medial meniscectomy.…”

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

“…The adductor canal is found in the middle 1/3 of the thigh and runs from the apex of the femoral triangle proximally to the adductor hiatus distally. Because the adductor canal consistently encloses the saphenous nerve and the nerve to the vastus medialis, placement of a catheter within the canal can potentially spare the major motor branches of the femoral nerve while still providing effective pain relief [19,22]. While the adductor canal technique may preserve quadriceps muscle strength compared to the femoral nerve block in volunteers, the effects, if any, on postoperative rehabilitation and discharge eligibility for actual patients undergoing TKA still remain to be studied [19].…”

The Comparing of Ultrasound-guided Techniques: Sciatic Block with Continuous Lumbar Plexus Block or Continuous Femoral Nerve Block for Anesthesia and Analgesia of Total knee Replacement

“…In agreement with our trial, Kaloul et al [8] suggest that obturator nerve involvement does not improve postoperative pain scores after TKR; Morin et al [9] come to the same conclusion. Preliminary results by Lund et al go in the opposite direction: continuous adductor-canal-blockade may be a valuable adjunct for post-operative analgesia after major knee surgery [12]. With this scenario we can affirm that, both for the intraoperative and postoperative period after TKR, the role of obturator nerve block remains unclear and further trials are therefore necessary to clarify this aspect.…”