Pro and Con: How Important Is the Exact Location of Adductor Canal and Femoral Triangle Blocks?

Motor-sparing regional anaesthesia for total knee arthroplasty: a narrative and systematic literature review

Total knee arthroplasty is a life-changing surgical procedure that is associated with a high incidence of severe postoperative pain. Key to enhancing recovery after surgery is effective analgesia and early mobilisation. Innovations in motor-sparing regional anaesthesia techniques that have improved recovery include targeted surgical local infiltration analgesia, adductor canal blockade, genicular nerve blocks, and the infiltration between the popliteal artery and posterior capsule of the knee (iPACK) block. This narrative review discusses the current available motor-sparing regional anaesthetic techniques and assesses the evidence supporting each.

Standardizing nomenclature in regional anesthesia: an ASRA-ESRA Delphi consensus study of upper and lower limb nerve blocks

BACKGROUND

Inconsistent nomenclature and anatomical descriptions of regional anesthetic techniques hinder scientific communication and engender confusion; this in turn has implications for research, education and clinical implementation of regional anesthesia. Having produced standardized nomenclature for abdominal wall, paraspinal and chest wall regional anesthetic techniques, we aimed to similarly do so for upper and lower limb peripheral nerve blocks.

METHODS

We performed a three-round Delphi international consensus study to generate standardized names and anatomical descriptions of upper and lower limb regional anesthetic techniques. A long list of names and anatomical description of blocks of upper and lower extremities was produced by the members of the steering committee. Subsequently, two rounds of anonymized voting and commenting were followed by a third virtual round table to secure consensus for items that remained outstanding after the first and second rounds. As with previous methodology, strong consensus was defined as ≥75% agreement and weak consensus as 50%-74% agreement.

RESULTS

A total of 94, 91 and 65 collaborators participated in the first, second and third rounds, respectively. We achieved strong consensus for 38 names and 33 anatomical descriptions, and weak consensus for five anatomical descriptions. We agreed on a template for naming peripheral nerve blocks based on the name of the nerve and the anatomical location of the blockade and identified several areas for future research.

CONCLUSIONS

We achieved consensus on nomenclature and anatomical descriptions of regional anesthetic techniques for upper and lower limb nerve blocks, and recommend using this framework in clinical and academic practice. This should improve research, teaching and learning of regional anesthesia to eventually improve patient care.

Effects of popliteal plexus block after total knee arthroplasty: a randomized clinical trial

BACKGROUND AND OBJECTIVES

Motor-sparing peripheral nerve blocks enhance multimodal opioid-sparing strategies after total knee arthroplasty. We hypothesized that adding a popliteal plexus block to a femoral triangle block could reduce 24-hour opioid consumption after total knee arthroplasty, compared with standalone femoral triangle block or adductor canal block.

METHODS

This patient- and assessor-blinded, randomized controlled trial allocated 165 patients into three equally sized parallel groups, receiving either 1) popliteal plexus block+femoral triangle block, 2) femoral triangle block, or 3) adductor canal block. Intravenous oxycodone was administered via patient-controlled analgesia pumps. The primary outcome was 24-hour postoperative opioid consumption. Secondary outcomes were preoperative maximum voluntary isometric contraction and manual muscle tests of knee and ankle movement assessed before and after the nerve block procedure together with postoperative pain scores, mobilization, and 12-hour opioid consumption.

RESULTS

24-hour postoperative intravenous oxycodone consumption varied significantly between groups (p<0.01), with medians (IQR) of 6 mg (2-12) in the popliteal plexus block+femoral triangle block group, 10 mg (8-16) in the femoral triangle block group, and 12 mg (6-18) in the adductor canal block group. Median consumption in the popliteal plexus block+femoral triangle block group was reduced by -4 mg (95% CI -7.4 to -1.0, p<0.01) and -6 mg (95% CI -8.3 to -1.3, p=0.01) compared with groups of femoral triangle block and adductor canal block, respectively. No differences were found in pain scores, mobilization, or changes in preoperative muscle strength. Post hoc analysis revealed successful 24-hour opioid-free postoperative care among 12 patients with popliteal plexus block+femoral triangle block, as compared with two with femoral triangle block and six with adductor canal block.

CONCLUSION

Adding a popliteal plexus block to a femoral triangle block resulted in a statistically significant reduction of 24-hour postoperative opioid consumption after total knee arthroplasty. However, no differences were found in pain scores. Popliteal plexus block did not impair the lower leg muscles.

Comparison between Combination of Proximal Adductor Canal Block and Infiltration between Popliteal Artery and Capsule of Knee (iPACK) with Large-Volume Distal Adductor Canal Block in Facilitating Early Mobilization after Total Knee Replacement: A Randomized, Single-Blind Study

Background:

Adductor canal block (ACB) and infiltration between popliteal artery and capsule of knee (iPACK) are popular block methods for analgesia after total knee replacement (TKR), covering both the anterior and posterior knee. This study aimed to compare the performance of the combination of ACB and iPACK with large-volume distal ACB in facilitating early mobilization after TKR.

Patients and Methods:

This study was a single-blind, randomized, controlled trial of 30 subjects who underwent TKR. Subjects were randomly assigned to either Group A (the large-volume distal ACB) or Group B (the combination of proximal ACB and iPACK). Outcome variables included postoperative time up and go (TUG) test, numeric rating scale (NRS), postoperative morphine consumption, block-performing time, time to first opioid rescue analgesia, and side effects.

Results:

This study found that the block-performing time was significantly shorter in Group A compared to Group B (230.67 vs. 509.67, P < 0.001). The mean postoperative TUG test (67 vs. 64, P = 0.78), NRS at all-time points, and postoperative morphine consumption (3 vs. 3 mg, P = 0.85) did not differ significantly. No block-related side effects were found in either group.

Conclusion:

Large-volume distal ACB is not superior to the combination of proximal ACB and iPACK in facilitating early mobilization after TKR. Block-performing time of distal ACB was shorter compared to the combination of proximal ACB and iPACK.

Comparison of migration rates between traditional and tunneled adductor canal block catheters: a randomized controlled trial

INTRODUCTION

Total knee arthroplasty is associated with significant postoperative pain. Continuous adductor canal blocks via an inserted adductor canal catheter are effective analgesia interventions with the advantage of decreasing quadriceps weakness and the potential of extending the analgesic effect. The classical adductor canal catheter insertion technique may have a high likelihood of catheter dislodgement out of the canal. The interfascial plane between the sartorius muscle and femoral artery (ISAFE) approach has the potential of decreasing the adductor canal catheter migration. The purpose of this study was to evaluate the incidence of catheter dislodgment to outside the adductor canal, for ISAFE and classical approaches. We hypothesized that ISAFE approach would result in a lower dislodgment rate.

METHODS

Ninety-seven patients for unilateral total knee arthroplasty were included and randomized to either ISAFE intervention group or conventional group. The primary outcome was the incidence of adductor canal catheter dislodged to outside the adductor canal, on ultrasound evaluation, 24 hours after the surgery. Secondary outcomes were pain scores, opioid consumption and continuous adductor canal block related complications for the first 48 hours after surgery.

RESULTS

The catheters placed using ISAFE approach had a lower rate of dislodgement in comparison to the control group (18.6% vs 44.9%, respectively, p=0.01), at 24 hours after surgery; and lower pain scores for rest, on the first two postoperative days.

CONCLUSIONS

ISAFE group had a significantly lower rate of dislodgement at 24 hours. The continuous adductor canal block analgesic benefit for knee arthroplasty depends on the position of the tip of the catheter inside the adductor canal.

Comparison of Analgesic Effects of Continuous Femoral Nerve Block, Femoral Triangle Block, and Adductor Block After Total Knee Arthroplasty: A Randomized Clinical Trial

OBJECTIVES

This study aimed to compare the analgesic effects of continuous femoral nerve block (FNB), femoral triangle block (FTB), and adductor canal block (ACB) following total knee arthroplasty (TKA). The goal was to identify the most effective nerve block technique among these.

METHODS

Patients undergoing TKA were randomly assigned to 1 of 3 groups: FNB, FTB, or ACB. Nerve blocks were administered preoperatively, with catheters placed for patient-controlled nerve analgesia (PCNA). The primary end point was the Numeric Rating Scale (NRS) score at movement at 24 hours postsurgery. Secondary end points included NRS scores at rest and movement, quadriceps strength, Timed Up and Go (TUG) test performance, range of motion, effective PCNA utilization, and opioid consumption at various postsurgery time points.

RESULTS

Of the 94 valid data sets analyzed (FNB: 31, FTB: 31, ACB: 32), significant differences were observed in the primary end point (H=7.003, P =0.03). Post hoc analysis with Bonferroni correction showed that the FNB group had a significantly lower median pain score (3 [2 to 4]) compared with the ACB group (4 [3 to 5], Bonferroni-adjusted P =0.03). Regarding secondary end points, both the FNB and FTB groups had significantly lower NRS scores than the ACB group at various time points after surgery. Quadriceps strength and TUG completion were better in the FTB and ACB groups. There were no statistically significant differences among the groups for the other end points.

DISCUSSION

Continuous FTB provides postoperative analgesia comparable to FNB but with the advantage of significantly less impact on quadriceps muscle strength, a benefit not seen with FNB. Both FTB and ACB are effective in preserving quadriceps strength postoperatively.

Application of ultrasound-guided single femoral triangle and adductor canal block in arthroscopic knee surgery: a prospective, double-blind, randomized clinical study

PURPOSE

To compare the difference in analgesic effect between femoral triangle block (FTB) and adductor canal block (ACB) during arthroscopic knee surgery.

METHODS

Patients who underwent arthroscopic knee surgery were randomized preoperatively to FTB group or ACB group. For each group, 20 mL of 0.1% ropivacaine was injected.

PRIMARY OUTCOMES

The numeric rating score (NRS) at 12 h after surgery at rest and during movement.

SECONDARY OUTCOME

(1) The NRS at post anesthesia care unit (PACU) and 2, 24 h after surgery at rest and during movement; (2) The quadriceps muscle strength at PACU and 2, 12, 24 h after surgery; (3) Consumption of Rescue analgesia; (4) Incidence of adverse reactions.

RESULTS

The NRS at 12 h after surgery at rest and during movement of ACB group were higher than FTB group. Among secondary outcomes, the NRS at PACU at rest and during movement, 2 h after surgery during movement of FTB group lower than ACB group; the quadriceps muscle strength at 2 h after surgery of FTB group stronger than ACB group. After multiple linear regression model analysis, the data showed additional statistically significant reduction NRS at 24 h after surgery at rest (0.757, p = 0.037) in FTB group. Other outcomes were similar between two groups.

CONCLUSIONS

The FTB appears to provide superior pain control after knee arthroscopy than ACB, the FTB is superior to the ACB in quadriceps muscle strength at 2 h after surgery.

TRIAL REGISTRATION

The trial was registered in the Chinese Clinical Trial Registry (ChiCTR2300068765). Registration date: 28/02/2023.

Bibliometric and visual analysis of research on analgesia and total knee arthroplasty from 1990 to 2022

Background

In recent decades, there have been notable advancements in the field of analgesia and total knee arthroplasty (TKA). This study aims to employ bibliometric analysis to elucidate the prevailing research focal points and trends within analgesia and TKA from 1990 to 2022.

Material and methods

Relevant publications were retrieved from the Web of Science Core Collection. CiteSpace, VOSviewer, and Scimago Graphica were used for visualization and bibliometric analysis of countries, institutions, authors, journals, references, and keywords.

Results

A total of 2776 publications on analgesia and TKA were identified, with the United States having the highest number of publications. The University of Copenhagen was the most productive institution, and Kehlet, Henrik was the most prolific author. The Journal of Arthroplasty had the most publications and citations. The most common keywords were "TKA," "pain management," "postoperative pain," "Total hip arthroplasty (THA)," and "postoperative management." Keyword burst detection demonstrated that adductor canal block (ACB) was a recent research hotspot.

Conclusion

Our study revealed a sharp increase in global publications on analgesia and TKA, and this trend is expected to continue. Further research is necessary to determine the optimal regimen for multimodal analgesia, the ideal location and volume of ACB, and their clinical significance.

Comparative Efficacy of iPACK vs Popliteal Sciatic Nerve Block for Pain Management Following Total Knee Arthroplasty: A Retrospective Analysis

Introduction Total knee arthroplasty (TKA) is associated with severe acute postoperative pain. The use of tourniquets and drains (T/D) is common in TKA but may have an influence on postoperative pain and muscular strength. The infiltration of local anesthetic between the popliteal artery and capsule of the knee (iPACK block) is a motor-sparing block that provides analgesia to the posterior aspect of the knee. However, evidence regarding its efficacy is scarce. This study aims to assess the effectiveness of iPACK block and the impact of T/D use on pain and muscular strength after TKA. Material and methods A retrospective study was carried out including patients who underwent TKA from January 2020 to April 2023. Patients were allocated into groups according to the peripheral nerve block performed and T/D use. Results We included 415 patients in this study. No differences were found in pain at rest or the need for rescue analgesia between patients who received an iPACK block or sciatic nerve block (SNB) with T/D applied. Patients who received a SNB reported lower pain scores on movement (p = 0.019), but with a higher prevalence of motor block (p < 0.001). Patients who underwent surgery without using T/D reported lower pain scores on movement (p = 0.021) and reduced need for rescue analgesia (p = 0.041). Conclusion These findings indicate that iPACK block can facilitate early mobilization after TKA without significant impact on postoperative muscle strength. Furthermore, the use of a T/D may be a source of postoperative pain that could compromise early rehabilitation.