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Year : 2020  |  Volume : 4  |  Issue : 4  |  Page : 148-151

Effectiveness of continuous adductor canal block versus continuous epidural analgesia in patients with total knee arthroplasty: A systematic review

Department of Anesthesiology and Intensive Care, Faculty of Medicine, Udayana University, Bali, Indonesia

Date of Submission27-May-2020
Date of Decision01-Jul-2020
Date of Acceptance09-Jul-2020
Date of Web Publication3-Nov-2020

Correspondence Address:
Dr. Christopher Ryalino
Department of Anesthesiology and Intensive Care, Faculty of Medicine, Udayana University, Jl. PB Sudirman, Denpasar 80232, Bali
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/BJOA.BJOA_96_20

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Background: This systematic review aimed to summarize the evidence base on randomized controlled trials (RCTs) comparing the continuous adductor canal block (CACB) and continuous epidural analgesia (CEA) in total knee arthroplasty (TKA) surgery. Methods: We searched the Cochrane Library, PubMed, and EMBASE database from the beginning of 2016 until 2020 to find RCTs published in English language, which have investigated pain score, length of stay (LOS), ambulation distance, and total opioid consumption in TKA. Results: Three RCTs were included in the final analysis. All of them employed similar argument that CACB is better than CEA in pain score, but only two of three studies investigated the other parameters such as LOS, ambulation distance, and opioid consumption, with the result that CACB is better than CEA. Conclusion: It was found that CACB was better in pain control compared to CEA, but there are very few similar studies. Future research is required to establish the therapeutic efficiency of CACB than CEA in TKA surgery.

Keywords: Continuous adductor canal block, continuous epidural analgesia, pain, total knee arthroplasty

How to cite this article:
Agung Senapathi TG, Fajar Narakusuma I P, Tanggono A, Ryalino C, Pradhana AP. Effectiveness of continuous adductor canal block versus continuous epidural analgesia in patients with total knee arthroplasty: A systematic review. Bali J Anaesthesiol 2020;4:148-51

How to cite this URL:
Agung Senapathi TG, Fajar Narakusuma I P, Tanggono A, Ryalino C, Pradhana AP. Effectiveness of continuous adductor canal block versus continuous epidural analgesia in patients with total knee arthroplasty: A systematic review. Bali J Anaesthesiol [serial online] 2020 [cited 2023 Mar 22];4:148-51. Available from: https://www.bjoaonline.com/text.asp?2020/4/4/148/299804

  Introduction Top

Total knee arthroplasty (TKA) is associated with some degree of postoperative pain; some analgesia techniques have already been used. Almost 80% of the patients suffer from moderate, severe, or extreme pain after TKA surgery. Pain can result in joint swelling, delayed recovery of muscle strength, decreased joint range of motion (ROM), and reduced walking ability.[1] Opioid analgesics that are traditionally used via parenteral or epidural route for pain control following TKA surgery are usually insufficient and can have side effects. Peripheral nerve blocks (PNBs) have become more widely used in recent years as they have fewer side effects and provide a comparable level of pain control.[2]

Previously, there was a continuous epidural technique that was relatively easy to insert and was generally used as a postoperative analgesic technique. Compared with traditional analgesia methods such as continuous epidural analgesia (CEA) and intravenous analgesia pump, continuous adductor canal block (CACB) can provide satisfactory and effective analgesia for patients after TKA and reduce the use of opioids and complications such as nausea and vomiting, suggesting that the quadriceps muscle strength of the patients in the CACB group was better than other PNB, hence it is considered the gold standard for postoperative analgesia after TKA.[1]

The adductor canal block (ACB) technique is used several times to treat postoperative pain in TKA patients. The application of ACB can be as a single-shot injection or as a continuous infusion via a catheter.[2] However, besides pain, other things that need to be taken into account as parameters for the success of a TKA surgery are length of stay (LOS), ambulation distance, and opioid consumption. Postoperative problems in TKA are not only pain but also involve the LOS of the patient and the speed of the patient to be able to “ambulate.” It is hoped that the injection of the ACB will be superior to the continuous epidural technique used earlier. The ACB is considered superior in terms of handling postoperative TKA treatment because, in addition to overcoming pain, it does not influence the strength of the quadriceps femoral muscle, which affects the distance and the speed of the patient to start ambulation exercises. CACB draws attention because it helps early ambulation and shortens the LOS.

Besides that, opioid administration also affects postoperative TKA treatment, and the more the opioids are given, the higher the risk of complications. Based on the data above, the authors would like to do a systematic review to compare CACB with CEA in TKA patients.

  Methods Top

We searched for studies investigating the effect of CACB versus CEA for postoperative TKA. We decided to include randomized controlled trial (RCT) studies. The review accorded to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement standards.

Search strategy

Databases including the Cochrane Library, PubMed, and EMBASE were searched with the following terms: (((adult) and ((adductor canal block) or (ACB))) and ((((total knee arthroplasty) or (TKA)) or ((total knee replacement) or (TKR)) and ((continuous epidural analgesia) or (CEA)) and (pain) to identify potentially eligible studies evaluating the efficacy of CACB versus CEA in postoperative TKA patients until May 2020 without language limitation, according to the search strategy recommended by the Cochrane Collaboration. The inclusion was determined using the following criteria:

  1. Study type: Clinical RCTs
  2. Population: Adult patients undergoing TKA without race, age, sex, weight, or limitations on the primary disease
  3. Intervention: The administration of CACB as an analgesia
  4. Comparator: The administration of CEA
  5. Outcome: Pain score, LOS, postoperative nausea and vomiting, and total opioid consumption. Disagreements within the selection of studies were discussed by the two authors or prosecuted by a third reviewer.

Literature screening and quality evaluation

The literature was filtered by two reviewers (FN and AT) based on the inclusion and exclusion criteria, independently. Each study title and abstract were reviewed. It was submitted to a third reviewer (TJ) if there was conflict appraisal. The data extracted from the studies included characteristics of the included studies, such as author, region, publication year, sample size, primary and secondary outcomes, as well as baseline characteristics of the included patients. The methodological quality of the included RCTs was evaluated according to the RCT evaluation criteria recommended by the Cochrane Handbook 5.1.0. There are five main aspects to be assessed, including randomization, concealment, blinding, selective reporting, and other source biases. The third reviewer resolves methodological quality disagreements.

Publication bias

Two authors independently assessed the risk of bias using Cochrane's “risk of bias 2 tool” [Figure 1], a system that establishes the risks of “high,” “low,” or “some concerns” bias in six domains, according to predetermined criteria [Figure 2].
Figure 1: Risk-of-bias graph

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Figure 2: Risk-of-bias summary

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  Results Top

After a preliminary search, a total of 21 articles were obtained. After reading the title, abstract, and full text, three repeated RCTs were potentially eligible for inclusion. A total of 428 patients were included in this study, including 202 patients with CACB and 226 patients with CEA. Baseline comparisons were performed in each included study, and the differences were not statistically significant as the included studies indicated [Table 1], [Figure 3].
Table 1: Characteristics of the included studies

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Figure 3: Process of identifying eligible studies for systematic review (Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram)

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Pain score

Based on three journals that include the inclusion and exclusion criteria, all of them discussed regarding postoperative pain. Two of the three journals calculated the postoperative visual analog scale (VAS) in the ward between the first 12–24 h after surgery.[3],[4] Meanwhile, according to Ortiz-Gomez et al., pain was assessed based on VRS-11 in the recovery room with the following four classifications: no pain = 0, mild = 1–3, moderate = 4–6, and severe = 7–10. In a study, on analyzing a total of 270 patients who underwent VAS assessments between the first 12 and 24 h after surgery, it was revealed that patients who received CACB were superior in terms of pain score than those who received CEA. While according to Ortiz-Gomezet al., patients who get CACB relatively do not feel pain or experience mild pain in the recovery room and so they do not need rescue analgesia in the recovery room.[5]

Postoperative opioid consumption

In their study, Ortiz-Gomez et al. did not measure total opioid consumption in the ward. They only measured the opioids used as rescue analgesic in the postanesthesia care unit.[5] According to Leung et al. and Kayupov et al., the CACB group gets fewer opioid rescue than the CEA group until they arrive at the ward.[3],[4]

Length of stay

Two of the three studies have reported about the duration of LOS. In a study by Kayupov et al. on a total of 270 patients to assess the outcome of LOS, it was found that groups that received ACB had shorter LOS than those who received CEA. Leung et al. disagreed, where Leung's results do not find a significant LOS difference between the CACB group and the CEA group. Meanwhile, according to Kayupovet al., LOS is combined with discharge day or postoperative day (POD). LOS is expressed in hours and minutes, whereas POD is assessed in days. The highest results are found on POD day 2 (POD#2) in CACB compared to the CEA group.

Ambulation distance

Leung et al. assessed that ambulation distance and knee ROM were not significantly affected in both CACB and CEA groups, and Leung et al. added a Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaire to assess functional outcome at weeks 3 and 6 postoperatively. The WOMAC score was superior in CACB groups at week 3 postoperatively, but not significant at week 6.[4]

  Discussion Top

The early postoperative period of TKA is associated with severe pain. In a systematic review, pain scales, total opioid used, and postoperative LOS were assessed in patients with TKA between the CACB group and CEA group. Patients' pain scale was evaluated using VAS 12 h postoperatively, and the results were lower in the CACB group compared to the CEA group.

The pathophysiology of opioid-induced nausea and vomiting is complex. Although a dose-dependent relationship exists, the concentration at which opioids produce adverse events is patient specific. Thus, even though total opioid consumption was significantly reduced with CACB, it may not have been reduced enough to minimize adverse events.[3]

ACBs cannot provide total analgesia around the knee after TKA because the knee is innervated by both the lumbar plexus (femoral and obturator nerve) and the sacral plexus (sciatic nerve). After all, the VAS in the CACB group is more controlled, so the total use of opioids is less than that of the CEA group, and this result proves that CACB is better at controlling pain compared to CEA.[2]

The adductor canal is located at the center of the thigh. The canal is roughly triangular in cross-section and is bounded by three muscles, namely quadriceps anterolaterally (specifically vastus medialis), sartorius medially, and adductor magnus posteriorly. It is formed by the upper boundary bordering the femoral triangle, with the lower limit being opened to the upper corner of the popliteal fossa. In the adductor canal, there is the femoral artery, the femoral vein, the posterior branch of the obturator nerve, and the branches of the femoral nerve, specifically the saphenous nerve in the medial ligaments in this canal. The articular ramus of obturatorius nerves enters the distal of the adductor canal. Most nerves are sensory nerves that regulate the knee joints.[6]

The ambulation distance of patients who received CACB was longer and farther than patients in the CEA group; this shows that patients who received CACB were relatively quick to recover and mobilize. Hence, the patient's time to be discharged from the hospital (POD) is also faster. We can conclude that CACB is superior to CEA. Leung et al., in their study, found that there was no clinical relevancy of the motor weakness, as seen by the equivalent of ambulation distance. The lack of discrete sensory motor testing was a limitation of this study. Given that up to 64% loss of quadriceps strength has been reported after TKA, even without a femoral nerve block, it is important not to further inhibit lower extremity motor function via motor nerve blockade.[4]

From journals that meet the inclusion and exclusion criteria, it is found that the sample population of patients who all underwent TKA operations with the following patient characteristics was enrolled from America and Europe. In contrast, no similar studies have been carried out in the Asian region. Here, we do not know if race and region affect pain. In these studies, it was not explained whether the operation was carried out unilaterally or bilaterally. There is no information whether the insertion of CACB and CEA is done via ultrasound guidance or not.

  Conclusion Top

We found that CACB is better in pain control and ambulatory capacity compared to CEA, but very few similar studies are available to review that the same. Future research is needed to establish the efficiency of CACB over CEA in TKA surgery.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Zhang Z, Wang Y, Liu Y. Effectiveness of continuous adductor canal block versus continuous femoral nerve block in patients with total knee arthroplasty: A PRISMA guided systematic review and meta-analysis. Medicine (Baltimore) 2019;98:e18056.  Back to cited text no. 1
Canbek U, Akgun U, Aydogan NH, Kilinc CY, Uysal AI. Continuous adductor canal block following total knee arthroplasty provides a better analgesia compared to single shot: A prospective randomized controlled trial. Acta Orthop Traumatol Turc 2019;53:334-9.  Back to cited text no. 2
Kayupov E, Okroj K, Young AC, Moric M, Luchetti TJ, Zisman G, et al. Continuous adductor canal blocks provide superior ambulation and pain control compared to epidural analgesia for primary knee arthroplasty: A randomized, controlled trial. J Arthroplasty 2017;33:1040-44. e1.  Back to cited text no. 3
Leung P, Dickerson DM, Denduluri SK, Mohammed MK, Lu M, Anitescu M, et al. Postoperative continuous adductor canal block for total knee arthroplasty improves pain and functional recovery: A randomized controlled clinical trial. J Clin Anesth 2018;49:46-52.  Back to cited text no. 4
Ortiz-Gomez JR, Pereperez-Candel M, Vazquez-Torres JM, Rodriguez-Delrio JM, Torron-Abad B, Fornet-Ruiz I, et al. Postoperative analgesia for elective total knee arthroplasty under subarachnoid anesthesia with opioids: Comparison between epidural, femoral block and adductor canal block techniques (with and without perineural adjuvants). A prospective, randomized, clinical trial. Minerva Anestesiol 2017;83:50-8.  Back to cited text no. 5
Zhang W, Hu Y, Tao Y, Liu X, Wang G. Ultrasound-guided continuous adductor canal block for analgesia after total knee replacement. Chin Med J (Engl) 2014;127:4077-81.  Back to cited text no. 6


  [Figure 1], [Figure 2], [Figure 3]

  [Table 1]


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