Continuous adductor canal block is superior to adductor canal block alone or adductor canal block combined with IPACK block (interspace between the popliteal artery and the posterior capsule of knee) in postoperative analgesia and ambulation following total knee arthroplasty: randomized control trial

Comparing Different Multimodal Analgesia Protocols for Primary Total Knee Arthroplasty-A Retrospective Cohort Analysis

Background: Several local regional anesthesia regimes have been described in the literature to reduce post-surgical pain following total knee arthroplasty (TKA), but it is unclear which regime has the best analgetic effect combined with the best motor function. The aim of this study was to determine if patients with infiltration between the popliteal artery and capsule of the posterior knee (IPACK) combined with an adductor canal block (SACB) had less pain, better motor function, and less opioid consumption after TKA than patients with a femoral nerve block (FNB) combined with a popliteal sciatic nerve block (PSB). Methods: In a retrospective cohort analysis, 342 patients following primary TKA were examined; 175 patients were treated with an IPACK combined with a SACB, and 167 patients with a femoral FNB combined with a PSB. The outcome parameters postoperative pain (visual analogue scale (VAS) for mobilization and at rest, functional recovery, opioid consumption, hospital discharge, and complications were analyzed and compared between both groups. Results: The IPACK/SACB group had a higher postoperative need for opioids despite higher doses of ropivacaine compared to the FNB/PSB group, accompanied by higher VAS scores. Patients' satisfaction was equal between the groups. Both groups showed comparable mobilization rates and walking distances following TKA. Conclusions: IPACK/SACB showed equal results compared to FNB/PSB for mobilization rates and patients' satisfaction following TKA without a reduction in opioid consumption.

IPACK Block Efficacy for Acute Pain Management after Total Knee Replacement: A Review

PURPOSE OF REVIEW

Patients often experience a significant degree of knee pain following total knee replacement (TKR). To alleviate this pain, nerve blocks may be performed such as the adductor canal block (ACB). However, ACBs are unable to relieve pain originating from the posterior region of the knee. A new type of nerve block known as the IPACK block may be used in conjunction with ACBs as it is designed to inhibit nerve branches innervating this area. In this article, we examine the rationale behind the IPACK procedure, how it is performed, and clinical trials examining its efficacy.

RECENT FINDINGS

5 of the 7 clinical trials examined in this article showed the IPACK + ACB block to show superior efficacy in treating pain following TKR compared to other blocks. These blocks included PMDI+ACB, SPANK+ACB, PAI+ACB, ACB alone, and SCAB. 2 of the 7 clinical trials showed the IPACK + ACB to be less effective in managing patients pain following TKR compared to other blocks which included the CACB and 4 in 1 block. In most instances, the IPACK + ACB showed superior efficacy in managing patients' pain following TKR when compared to other types of nerve blocks. This was determined by measuring usage of opioids, reported postoperative pain, and length of hospital stays following TKR. Thus, we suppose the IPACK block may be used in conjunction with the ACB to effectively reduce patient's pain following TKR.

Infiltration of local anesthetic in the Interspace between the popliteal artery and capsule of the posterior knee "IPACK block" versus adductor canal block "ACB" for pain relief after open wedge high tibial osteotomy: a randomized clinical trial

BACKGROUND

A high tibial osteotomy is usually associated with severe postoperative pain. Both adductor canal block (ACB) and interspace between the popliteal artery and capsule of the posterior knee (IPACK) have been described as effective block techniques for providing analgesia after knee surgeries, with few comparisons in wedge osteotomy cases. We aim to compare the postoperative analgesic profile of the previously mentioned two block techniques in patients undergoing tibial osteotomies.

METHODS

Sixty patients were enrolled in this randomized prospective trial (30 received IPACK and 30 received ACB). Both blocks were installed before the spinal anesthesia after infiltration of 2 mL lidocaine 2%. Twenty mL of bupivacaine 0.25% mixed with dexamethasone as anesthetic adjuvant were used for both blocks. The postoperative analgesic profiles were compared between the two groups.

RESULTS

Postoperative pain scores were lower in the IPACK group, and that decrease was evident throughout the first 10 hours postoperatively. Additionally, the duration of analgesia was much prolonged with the same block (487.50±82.39 vs. 301.93±92.06 minutes with ACB). There was a significant decline in postoperative analgesic consumption (1.27±0.45 vs. 1.8±0.61 gm, P=0.000), and a significant increase in the ambulation distance (19.10±0.60 vs. 17.73±0.45 m, P=0.000) with a significant decline in the duration of hospitalization (43.27±7.61 vs. 54±8.35 hours) in the IPACK group compared to the ACB group.

CONCLUSIONS

IPACK is a superior block technique compared to ACB in patients undergoing high tibial osteotomy regarding postoperative analgesia, ambulation distance, and patient satisfaction with little rate of adverse events in both groups.

Adductor Canal Block Versus Femoral Nerve Block in Total Knee Arthroplasty: Network Meta-Analysis

OBJECTIVES

The quality of postoperative analgesia in total knee arthroplasty is crucial for patient recovery, rehabilitation, and hospital stay duration. In line with the above, а single-shot adductor canal block has been considered as an improved method over continuous femoral nerve block. However, continuous adductor canal block and single-shot femoral nerve block have been not adequately addressed in the discussion. This study aimed to compare the effectiveness of various types of adductor and femoral nerve blocks on clinically relevant outcomes in patients following total knee arthroplasty.

METHODS

A systematic review and network meta-analysis were conducted following "PRISMA-NMA" and Cochrane Handbook guidelines. The eligibility criteria included randomized trials and, where these were lacking for a comparison, nonrandomized studies involving adults undergoing primary total knee arthroplasty, comparing single-shot adductor canal block, continuous adductor canal block, single-shot femoral nerve block, and continuous femoral nerve block.

RESULTS

A total of 36 studies involving 3308 patients were included. Single-shot adductor canal block showed higher pain scores and opioid consumption but better functional recovery at 24 h compared with continuous femoral nerve block. However, this trend vanishes by the 48 h assessment postsurgery. Continuous adductor canal block required higher opioid consumption but better functional recovery and shorter hospital stay compared with continuous femoral nerve block. Single-shot adductor canal block showed higher pain scores but comparable opioid consumption and functional recovery to continuous adductor canal block.

DISCUSSION

The shift from continuous femoral nerve block to single-shot adductor canal block as the preferred method for pain relief after total knee arthroplasty may be premature. While the latter improves mobility, it falls short in pain control and does not shorten hospital stays. Continuous adductor canal block shows promise but is currently underappreciated, and single-shot femoral nerve block is often overshadowed by other techniques in regional anesthesia. Further high-quality, multicenter randomized controlled trials are needed to validate these findings.

Systematic reviews and meta-analyses in regional anesthesia and pain medicine (Part II): guidelines for performing the systematic review

In Part I of this series, we provide guidance for preparing a systematic review protocol. In this article, we highlight important steps and supplement with exemplars on conducting and reporting the results of a systematic review. We suggest how authors can manage protocol violations, multiplicity of outcomes and analyses, and heterogeneity. The quality (certainty) of the evidence and strength of recommendations should follow the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. It is our goal that Part II of this series provides valid guidance to authors and peer reviewers who conduct systematic reviews to adhere to important constructs of transparency, structure, reproducibility, and accountability. This will likely result in more rigorous systematic reviews being submitted for publication to the journals like Regional Anesthesia & Pain Medicine and Anesthesia & Analgesia.

Efficacy of adding infiltration between the popliteal artery and the capsule of the posterior knee (IPACK) to adductor canal block and local infiltration analgesia in total knee arthroplasty: A retrospective cohort study

OBJECTIVE

Local infiltration analgesia (LIA), adductor canal block (ACB), and infiltration between the popliteal artery and the capsule of the posterior knee (IPACK) are popular multimodal analgesia techniques used during total knee arthroplasty (TKA). This study aimed to explore the efficacy of adding the IPACK technique to ACB and LIA in patients undergoing TKA.

METHODS

In this retrospective cohort study, patients who underwent primary unilateral TKA were divided into two groups based on their date of admission. Sixty-three patients underwent IPACK, ACB and LIA (IPACK group) during surgery, while 60 patients underwent ACB and LIA (control group). The primary outcome was the postoperative administration of morphine hydrochloride as a rescue analgesic. Secondary outcomes included time to first rescue analgesia, postoperative pain assessed using the visual analog scale (VAS), functional recovery assessed by knee range of motion and ambulation distance, time until hospital discharge, and complication rates.

RESULTS

The two groups were similar in average postoperative 0-to-24-h morphine consumption (11.8 mg for the control group vs 12.7 mg for the IPACK group, p = .428) and average total morphine consumption (18.2 mg vs 18.0 mg, p = .983) during hospitalization. There were also no significant differences in the secondary outcomes.

CONCLUSIONS

The addition of IPACK to ACB and LIA did not provide any clinical analgesic benefits. Orthopedic surgeons and anesthesiologists are justified in using ACB and LIA without IPACK for TKA.

Systematic Reviews and Meta-analyses in Regional Anesthesia and Pain Medicine (Part II): Guidelines for Performing the Systematic Review

In Part I of this series, we provide guidance for preparing a systematic review protocol. In this article, we highlight important steps and supplement with exemplars on conducting and reporting the results of a systematic review. We suggest how authors can manage protocol violations, multiplicity of outcomes and analyses, and heterogeneity. The quality (certainty) of the evidence and strength of recommendations should follow the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. It is our goal that Part II of this series provides valid guidance to authors and peer reviewers who conduct systematic reviews to adhere to important constructs of transparency, structure, reproducibility, and accountability. This will likely result in more rigorous systematic reviews being submitted for publication to the journals like Regional Anesthesia & Pain Medicine and Anesthesia & Analgesia .

Periarticular injection, iPACK block, and peripheral nerve block in pain management after total knee arthroplasty: a structured narrative review

INTRODUCTION

Total knee arthroplasty (TKA) is commonly performed in patients with end-stage osteoarthritis or rheumatoid arthritis of the knee to reduce joint pain, increase mobility, and improve quality of life. However, TKA is associated with moderate to severe postoperative pain, which remains a significant clinical challenge. Surgeon-administered PAI and anesthesiologist-administered iPACK have proven viable alternatives to conventional peripheral nerve blocks. This review aims to discuss which IPACK block or periarticular injection, combined or not with different peripheral nerve blocks, has better effects on postoperative rehabilitation, patient satisfaction, and overall outcome.

MATERIAL AND METHODS

The literature review was performed on standards of care, current therapeutic options, a pain management protocol, and innovative treatment options for patients undergoing total knee arthroplasty. The literature was reviewed through four electronic databases: PubMed, Cochrane Library, Google Scholar, and Embase.

RESULTS

The initial search yielded 694 articles. Fifty relevant articles were selected based on relevance, recentness, search quality, and citations. Six studies compared PAI to peripheral nerve block (PNB), and eight studies checked the effectiveness of adding PNB to PAI. Three studies compared iPACK to PNB, and ten reviewed the point of adding PNB to iPACK.

CONCLUSIONS

The literature review indicates that the best analgesic effect is obtained by combining PAI or iPACK with a peripheral nerve block, particularly with ACB, due to its analgesic, motor-sparing effect, and satisfactory analgesia.

Comparison of Different Concentrations of Ropivacaine Used for Ultrasound-Guided Adductor Canal Block + IPACK Block in Total Knee Arthroplasty

This study aimed to compare the analgesic efficacy of different concentrations of ropivacaine used for the combination of ultrasound-guided adductor canal block (ACB) and infiltration between the popliteal artery and capsule of the posterior knee (IPACK) block in total knee arthroplasty (TKA). Before general anesthesia, 90 patients undergoing TKA were randomized to receive ACB + IPACK block with ropivacaine 0.2, 0.25, or 0.3% (defined as group A, B, and C, respectively). Primary outcome was the reported visual analog scale (VAS) pain scores at rest 30 minutes following arrival to the postanesthesia care unit (PACU). Secondary outcomes were postoperative VAS pain scores, postoperative morphine consumption, the time to first rescue analgesia, functional recovery of knee (including the range of motion and quadriceps strength), and postoperative complications. Compared with group A, group B and group C had significantly lower VAS scores 30 minutes following arrival to the PACU (p < 0.001 and p < 0.001, respectively). These two groups also had significantly lower VAS pain scores at postoperative 2 hours (at rest: p = 0.037 and 0.002; during motion: p = 0.035 and 0.001, respectively) and 6 hour (at rest: p = 0.033 and 0.002; during motion: p < 0.001 and p < 0.001, respectively), lower postoperative morphine consumption (p = 0.001 and 0.002, respectively), longer time to first rescue analgesia (p = 0.010 and 0.009, respectively), and better range of knee motion on the day of surgery (p = 0.008 and 0.002, respectively). Group B and group C showed no significant differences in these outcomes between each other (p > 0.05). The three groups did not show a significant difference in postoperative quadriceps strength and complication rates (p > 0.05). Compared with ropivacaine 0.2%, ropivacaine 0.25 and 0.3% can provide early pain relief in the first 6 hours after surgery. Ropivacaine 0.25 and 0.3% may provide more clinical benefits for patients undergoing outpatient TKA.

Motor-sparing peripheral nerve blocks for hip and knee surgery

PURPOSE OF REVIEW

To summarize the recent literature describing and comparing novel motor-sparing peripheral nerve block techniques for hip and knee surgery. This topic is relevant because the number of patients undergoing same day discharge after hip and knee surgery is increasing. Preserving lower extremity muscle function is essential to facilitate early physical therapy for these patients.

RECENT FINDINGS

Distal peripheral nerve blocks may allow for preserved quadriceps motor strength and comparable analgesia to traditional techniques. However, few studies in hip and knee populations include strength or function as primary outcomes. For hip surgeries, studies have failed to show analgesic differences between regional blocks and periarticular infiltration. Similarly for knee arthroplasty in the absence of periarticular infiltration, recent evidence suggests adding combinations of blocks (ACB plus iPACK or genicular nerve blocks) may balance pain control and early ambulation.

SUMMARY

The use of motor-sparing peripheral nerve block techniques enables early ambulation, adequate pain control, and avoidance of opioid-related side effects facilitating outpatient/ambulatory lower extremity surgery. Further studies of these techniques for continuous peripheral nerve block catheters are needed to assess if extended blockade continues to provide motor-sparing and opioid-sparing benefits.

Evaluation of Postoperative Analgesic Efficacy of Ultrasound-Guided Suprainguinal Fascia Iliaca Block in Knee Arthroplasty: Prospective, Randomized, Feasibility Study

BACKGROUND

Total Knee Arthroplasty (TKA) is one of the most commonly performed orthopedic procedures, and patients complain of severe pain in the postoperative period. The supra-inguinal fascia iliaca block (SIFIB) works as an anteriorly applied lumbar plexus block and is frequently used in hip surgeries. In this study, we evaluated the effect of SIFIB in patients undergoing TKA under spinal anesthesia.

METHODS

This study is a prospective, randomized, assessor-blinded feasibility study conducted in a tertiary hospital. Eighty-six patients with ASA I-III were initially enrolled, and after exclusions, 80 patients were randomized into two equal groups (SIFIB and control groups). The standard multimodal analgesia was applied to the control group, while SIFIB was additionally applied to the block group. The study measured the morphine requirement in PCA and pain intensity using Numeric Rating Scores between the two groups.

RESULTS

the 24-h cumulative morphine consumption was lower in Group SIFIB. Although there was a decrease in NRS at rest scores in the SIFIB group during some time periods, pain was moderate, and no differences in pain scores were recorded during exercise in all patients.

CONCLUSIONS

In patients undergoing TKA under spinal anesthesia, a single shot of SIFIB results in a significant reduction in the amount of morphine consumed in hours. This effect was most likely related to a decrease in pain at rest in the SIFIF group.

Clinical effects of interspace between the popliteal artery and capsule of the posterior knee block with multimodal analgesia for total knee arthroplasty: a systematic review and meta-analysis

PURPOSE

Combination of regional anaesthesia technique that is most effective in analgesia and postoperative functional outcome with the fewest complications needs investigation. Interspace between the popliteal artery and the capsule of the posterior knee block (IPACK) has been introduced clinically. We evaluated the efficacy of IPACK in combination with other nerve blocks after total knee arthroplasty.

METHODS

Data were obtained from PubMed, Cochrane Library, Web of Science, and Sciencedirect. Studies that compared outcomes using IPACK combined with other regional nerve blocks after total knee arthroplasty with other analgesic modalities and those which used pain scores or opioid consumption as primary or secondary outcomes were included.

RESULTS

Seventeen articles (20 trials, 1652 patients) were included. IPACK supplementation significantly reduced rest pain scores after total knee arthroplasty at postoperative hours 8-12(95%CI - 0.85 [- 1.36, - 0.34], I2 = 94%, p = 0.001), postoperative day 1 (95% CI - 0.49 [- 0.85, - 0.14], I2 = 87%, p = 0.006), and postoperative day 2 (95% CI - 0.28 [- 0.51, -0.05], I2 = 72%, p = 0.02); there was no significant difference at postoperative day 3 or discharge (95% CI - 0.14 [- 0.33, 0.05], I2 = 0%, p = 0.14). Combination treatment resulted in reduced dynamic pain scores at postoperative hours 8-12 (95%CI - 0.52 [- 0.92, - 0.12], I2 = 86%, p = 0.01) and postoperative day 1(95% CI - 0.49 [- 0.87, - 0.11], I2 = 88%, p = 0.01). There was no difference between postoperative day 2(95% CI - 0.29 [- 0.63, 0.05], I2 = 80%, p = 0.09), postoperative day 3 or discharge (95% CI - 0.45 [- 0.92, 0.02], I2 = 83%, p = 0.06). In addition, it strongly reduced postoperative opioid consumption within 24 H (95% CI - 0.76 [- 1.13, - 0.39], I2 = 85%, p < 0.00001), 24-48 H (95% CI - 0.43 [- 0.85, - 0.01], I2 = 83%, p = 0.04), and total opioid use (95% CI - 0.64 [- 1.07, - 0.22], I2 = 86%, p = 0.003). Although IPACK supplementation improved timed up and go test and walking distance at postoperative day 2, there was no statistically significant difference at other time periods or obvious improvement in knee range of motion and quadriceps strength. IPACK block supplementation could shorten the length of stay (LOS) (95% CI - 0.40 [- 0.64, - 0.15], I2 = 70%, p = 0.001) and improve patient satisfaction (95% CI 0.43 [0.01, 0.84], I2 = 87%, p = 0.04).

CONCLUSION

Based on these results, IPACK supplementation, in addition to standard postoperative analgesia, can be used effectively and safely to relieve early postoperative pain after total knee arthroplasty.

Peripheral Nerve Catheter Reduces Postoperative Opioid Consumption and Pain in Revision Total Knee Arthroplasty

Background

Patients undergoing revision total knee arthroplasty (rTKA) have historically received high doses of opioids during the perioperative period. As awareness of opioid use has heightened, opioid administration has continuously decreased. This study aimed to evaluate if peripheral nerve catheter (PNC) use in rTKA reduces opiate consumption while maintaining similar pain control and postoperative function levels.

Methods

A retrospective review of 354 patients who underwent rTKA between July 2019 and January 2022 was conducted. Fifty total patients who received an adductor canal PNC were propensity-matched 1:1 to a control group of 50 patients that did not receive a PNC. To assess the primary outcome of opiate consumption, nursing documented opiate administration events were converted into morphine milligram equivalents per 24-hour interval. Postoperative pain and functional status were assessed using the verbal rating scale for pain and the Activity Measure for Post-Acute Care scores, respectively.

Results

Compared to the control group, the PNC group demonstrated significantly lower overall inpatient opiate consumption (98.68 ± 117.03 vs 176.69 ± 203.47 morphine milligram equivalents; 44.15% decrease, P = .021) and lower verbal rating scale pain scores at 60 to 72 hours postoperatively (4.85 ± 1.24 vs 5.83 ± 1.35; 16.81% decrease, P = .038). There was no significant difference in Activity Measure for Post-Acute Care scores postoperatively (raw score: 19.41 ± 3.61 vs 19.46 ± 3.18; 0.26% decrease, P = .952). Finally, the PNC cohort was significantly less likely to be readmitted within 90 days after surgery (0.0% vs 12.0%; P = .012).

Conclusions

In rTKA patients, PNC can significantly reduce inpatient opioid consumption while maintaining a comparable functional recovery and superior pain control.

Level III Evidence

Retrospective Cohort Study.

Does the Addition of iPACK Block to Adductor Canal Block Provide Improved Analgesic Effect in Total Knee Arthroplasty? A Systematic Review and Meta-Analysis

The interspace between popliteal artery and the capsule of posterior knee (iPACK) block was proposed in recent years to relieve posterior knee pain. Since adductor canal block (ACB) and iPACK involve different branches of the sensory nerves, it is theoretically feasible to combine iPACK block and ACB to relief pain after total knee arthroplasty (TKA). We aim to validate the efficacy of adding iPACK block to ACB in the setting of a multimodal pain management protocol following TKA. A comprehensive literature review on Web of Science, Embase, the Cochrane Library, and PubMed was performed. Eight studies (N = 1,056) that compared the efficacy of iPACK block + ACB with ACB alone were included. Primary outcomes consisted of Visual Analogue Scale (VAS) score at rest or during activity at various time points. Secondary outcomes include opioids consumption, walking distance, and length of hospital stay (LOS). Compared to ACB alone, VAS scores at rest (standardized mean difference [SMD]: -1.18; 95% confidence interval [CI]: -2.05 to -0.30) and during activity (SMD: -0.26; 95% CI: -0.49 to -0.03) on the day of surgery were lower in the iPACK block + ACB group. However, the difference did not reach the minimal clinically important difference. Opioids consumption at postoperative 24 hours was lower in the iPACK + ACB group (SMD: -0.295; 95% CI: -0.543 to -0.048). VAS score on postoperative day (POD) 1 and POD2, opioids consumption from 24 to 48 hours, walking distance, and LOS were not different. In conclusion, the addition of iPACK block to ACB in a multimodal pain management protocol can effectively reduce opioids consumption in the early postoperative period. This is a level III, meta-analysis study.

Analgesic benefits of single-shot versus continuous adductor canal block for total knee arthroplasty: a systemic review and meta-analysis of randomized trials

BACKGROUND

Adductor canal block (ACB) can provide important analgesic benefits following total knee arthroplasty (TKA), however, the extent to which these benefits can be enhanced or prolonged by a continuous catheter-based infusion compared with a single-shot injection of local anesthetic is unclear.

OBJECTIVES

This systematic review and meta-analysis (PROSPERO: CRD42021292738) review sought to compare the analgesic effectiveness of single shot to continuous ACB following TKA.

EVIDENCE REVIEW

We sought randomized trials from the US National Library of Medicine database (MEDLINE), Excerpta Medica database (EMBASE), and Cochrane Database of Systematic Reviews from inception to November 1, 2021, that compared single-shot to continuous ACB in adult patients undergoing TKA. The primary outcomes were (1) area under the curve (AUC) pain severity at rest and (2) cumulative opioid (oral morphine equivalent) consumption during the first 48 hours postoperatively. Secondary outcomes included postoperative pain severity scores up to 48 hours, cumulative opioid consumption at 24 hours, functional recovery, opioid-related side effects, and block-related complications. Risk of bias of included studies was assessed using the Cochrane risk of bias tool. Statistical pooling was conducted using the Hartung-Knapp-Sidik-Jonkman method for random effects. No funding was obtained for this review.

FINDINGS

Eleven trials (1185 patients) were included. No differences were observed in rest pain severity (AUC) or cumulative opioid consumption up to 48 hours postoperatively. In addition, no differences were observed in individual postoperative rest pain scores in the recovery room and at 12 and 24 hours, or in cumulative opioid consumption at 24 hours, functional recovery, and opioid-related side effects. Finally, fewer block-related complications were observed with single-shot ACB, with an OR (95% CI) of 0.24 (0.14 to 0.41) (p=0.002).

CONCLUSIONS

Our results suggest that continuous catheter-based ACB does not enhance or prolong the analgesic benefits when compared with single-shot ACB for TKA over the first 48 hours postoperatively. Overall, the results of our meta-analysis do not support the routine use of continuous ACB for postoperative analgesia after TKA.

Minimum effective volume of ropivacaine for ultrasound-guided adductor canal + IPACK block in total knee arthroplasty: A double-blind, randomized dose-finding trial

BACKGROUND

Our previous study reported that when a respective 20 mL of ropivacaine was used for adductor canal block (ACB) combined with infiltration between the popliteal artery and capsule of the posterior knee (IPACK) block for patients undergoing total knee arthroplasty (TKA), the minimum concentration of 0.275% could provide successful block in almost all patients. Based on the results, the primary objective of this study was to investigate the minimum effective volume (MEV₉₀, defined as the volume which can provide successful block in 90% of patients) of ACB + IPACK block.

METHODS

This double-blind, randomized dose-finding trial was based on a biased coin up-and-down sequential design, where the volume of ropivacaine administered to a given patient depended on the previous patient's response. The first patient received 15 mL of 0.275% ropivacaine for ACB and again for IPACK. If the block failed, the next subject received a 1 mL higher volume for ACB and IPACK, respectively; otherwise, the next subject received either a 1 mL lower volume (probability of 0.11) or the same volume (probability of 0.89). The primary outcome was whether the block was successful. Block success was defined as the patient did not suffer significant pain and did not receive rescue analgesia within 6 h after surgery. Then the MEV₉₀ was estimated by isotonic regression.

RESULTS

Based on analysis of 53 patients, the MEV₉₀ was 17.99 mL (95% CI 17.47-18.61 mL), MEV₉₅ was 18.48 mL (95% CI 17.45-18.98 mL) and MEV₉₉ was 18.90 mL (95% CI 17.38-19.07 mL). Patients whose blocks succeeded had significantly lower NRS pain scores, lower morphine consumption, and shorter hospitalization.

CONCLUSION

0.275% ropivacaine in 17.99 mL respectively can provide successful ACB + IPACK block in 90% of patients undergoing TKA. The minimum effective volume (MEV₉₀) of ACB + IPACK block was 17.99 mL.

Continuous vs. single-shot adductor canal block for pain management following primary total knee arthroplasty: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Adductor canal block (ACB) provides effective analgesia following total knee arthroplasty (TKA). This systematic review aimed to compare continuous and single-shot ACB for pain management and functional recovery following TKA.

METHODS

MEDLINE, Embase, Web of Science and CENTRAL were searched up to January 5th, 2021. Included studies were randomized controlled trials comparing continuous to single-shot ACB for postoperative pain management after primary TKA. Primary outcome was opioid consumption and secondary outcomes were pain intensity, quadriceps strength, mobility, complications, and length of hospital stay. Meta-analyses were performed using random-effects method.

RESULTS

Eleven studies (910 patients) were included in this systematic review. Continuous ACB did not significantly decrease opioid consumption (8 studies; 642 patients; MD=-5.67; 95% CI: -13.87 to 2.54; I²=13%) but significantly decreased 48hours pain scores (10 studies; 852 patients; MD=-0,73; 95% CI: -0.93 to -0.54; I²=54%). Continuous ACB improved quadriceps strength (4 studies; 250 patients; SMD=0.59; 95% CI: 0.16 to 1.03; I²=63%) but not Timed Up and Go test performance (5 studies; 524 patients; MD=3.99; 95% CI: -8.98 to 1.01; I²=89%). Type of ACB did not affect nausea and vomiting (5 studies; 357 patients; RR=1.23; 95% CI: 0.65 to 2.34; I²=0%) nor length of hospital stay (8 studies; 655 patients; MD=-0.13; 95% CI: -0.28 to 0.01; I²=36%).

CONCLUSION

Continuous ACB did not reduce opioid consumption following TKA. Larger trials are required.

Regional anaesthesia: what surgical procedures, what blocks and availability of a “block room”?

PURPOSE OF REVIEW

With an expected rise in day care procedures with enhanced recovery programs, the use of specific regional anaesthesia can be useful. In this review, we will provide insight in the used regional block and medication so far known and its applicability in a day care setting.

RECENT FINDINGS

Regional anaesthesia has been improved with the aid of ultrasound-guided placement. However, it is not commonly used in the outpatient setting. Old, short acting local anaesthetics have found a second life and may be especially beneficial in the ambulatory setting replacing more long-acting local anaesthetics such as bupivacaine.To improve efficiency, a dedicated block room may facilitate the performance of regional anaesthesia. However, cost-efficacy for improved operating time, patient care and hospital efficiency has to be established.

SUMMARY

Regional anaesthesia has proven to be beneficial in ambulatory setting. Several short acting local anaesthetics are favourable over bupivacaine in the day care surgery. And if available, there are reports of the benefit of an additional block room used in a parallel (monitored) care of patients.

Analgesic efficacy of adding the IPACK block to multimodal analgesia protocol for primary total knee arthroplasty: a meta-analysis of randomized controlled trials

BACKGROUND

Total knee arthroplasty (TKA) is a standard treatment for end-stage degenerative knee disease. Most patients will experience moderate-to-severe postoperative knee pain, significantly affecting rehabilitation. However, controversy remains regarding the efficacy of adding the interspace between the popliteal artery and capsule of the knee (IPACK) into multimodal analgesia protocol.

METHODS

PubMed, Medline, Embase, Cochrane Library, and other databases were searched from inception to February 1, 2021. Studies comparing patients receiving IPACK to patients not receiving IPACK were included. The primary outcome was the ambulation pain score on a visual analogue scale (VAS) of 0-10. Secondary outcomes included pain score at rest, morphine usage, functional recovery, clinical outcomes, and complications.

RESULTS

Thirteen RCTs involving 1347 knees were included. IPACK was associated with lower ambulation pain scores (weight mean difference [WMD] - 0.49, 95% confidence interval [CI] - 0.72 to - 0.26). The benefits were observed from 2 to 4 h, 6 to 12 h, and beyond one week. IPACK also significantly reduced rest pain scores (WMD - 0.49, 95% CI - 0.74 to - 0.24), and the benefits were observed from 6 to 12 h and beyond one week. IPACK reduced the overall morphine consumption (WMD - 2.56, 95% CI - 4.63 to - 0.49). Subgroup analysis found reduced oral morphine consumption from 24 to 48 h (WMD - 2.98, 95% CI - 5.71 to - 0.24) and reduced rate of morphine requirement from 12 to 24 h (relative risk [RR] = 0.51, 95% CI 0.31 to 0.83). Functional recovery outcomes regarding ambulation distances (on the second postoperative day [POD2]) (WMD = 1.74, 95% CI 0.34 to 3.15) and quadriceps muscle strength (at 0 degree) (WMD = 0.41, 95% CI 0.04 to 0.77) favored IPACK. And IPACK reduced the rate of sleep disturbance (on POD 1) (RR = 0.39, 95% CI 0.19 to 0.81). There was no significant difference in the other outcomes.

CONCLUSIONS

Moderate-level evidence confirmed that IPACK was related to better results in pain scores, morphine usage, and functional recovery without increasing the risk of complications.

REGISTRATION

CRD42021252156.

IPACK (Interspace between the Popliteal Artery and the Capsule of the Posterior Knee) Block Combined with SACB (Single Adductor Canal Block) Versus SACB for Analgesia after Total Knee Arthroplasty

OBJECTIVES

To evaluate the combination of the infiltration between the popliteal artery and the posterior capsule of the knee (iPACK) block and single adductor canal block (SACB) versus SACB for motor-sparing knee analgesia effects after total knee arthroplasty (TKA).

METHODS

PubMed, Ovid, Cochrane Library, and other databases were searched from the inception to January 2021. Randomized controlled trials (RCTs) comparing patients receiving iPACK plus SACB with patients receiving SACB after TKA were included. The included studies were assessed by two reviewers according to the Cochrane risk of bias criteria. Meta-analysis was performed with STATA 13.0 software, the risk ratios (RR) and mean differences (MD) were used to compare dichotomous and continuous variables. The primary outcome was ambulation pain and secondary outcomes were rest pain, opioid consumption, function ability, clinical outcomes, and complications.

RESULTS

Seven RCTs (304 knees in iPACK + SACB group; 305 knees in SACB group) were included. The follow-up periods ranged from 2 days to 3 months. Pooled data indicated lower pain scores at ambulation (p < 0.0001) for iPACK + SACB. When comparing the pain scores of subgroups analyzed at specific periods, lower scores in subgroups within 12 h (at rest and ambulation) and after 48 h (at ambulation) were observed in the iPACK + SACB group. Analysis demonstrated greater reduction in morphine consumption (p = 0.007) in the iPACK + SACB group. The iPACK + SACB group is also superior to the SACB group regarding function ability, which included range of motion (ROM) (p = 0.001), time up to go (TUG) test (p = 0.030), and ambulation distance (p < 0.0001). No difference was found in clinical outcomes or complications.

CONCLUSIONS

With the iPACK added to SACB, pain scores, morphine consumption, functional ability were improved. Additional high-quality studies are required to further address this topic.

iPACK block (local anesthetic infiltration of the interspace between the popliteal artery and the posterior knee capsule) added to the adductor canal blocks versus the adductor canal blocks in the pain management after total knee arthroplasty: a systematic review and meta-analysis

Background

Several studies have suggested that the addition of iPACK block (the popliteal artery and the posterior knee capsule have been given interspace local anesthetic infiltration) might get better analgesia than adductor canal block (ACB) only after total knee arthroplasty (TKA). This paper compiles all available evidence on the effect of two analgesia regimens (ACB and iPACK + ACB) involving all sides.

Methods

We searched in eight major databases for all clinical trials discussing the effect of two analgesia regimens after TKA. Statistical analyses were conducted by Stata and RevMan Software. In addition, we performed GOSH analysis, subgroup analysis, meta-regression analysis to study the source of heterogeneity. Publication bias was checked using Egger’s test. Trim-and-fill analysis was applied in terms of sensitivity analysis of the results.

Results

There are fourteen eligible studies for our meta-analysis. There are significant differences between the two groups in VAS score at rest and with activity, and the VAS scores were lower in the ACB + iPACK Group (VAS scores at rest: 95%CI [− 0.96, − 0.53], P < 0.00001. VAS scores with activity: 95%CI [− 0.79, − 0.43], P < 0.00001). A differential was discovered to support the ACB + iPACK Group when comparing the two groups on postoperative cumulative morphine consumption (95%CI: [− 0.52, − 0.14], P: 0.0007). The patients in the group of ACB + iPACK performed better in the postoperative range of knee movement (95%CI: [5.18, 10.21], P < 0.00001) and walking distance (95%CI: [0.15, 0.41], P < 0.00001). There were significant differences between the patients in the ACB + iPACK Group and ACB Group on the TUG test of POD1 and POD2. We found that patients' hospital stays in the ACB + iPACK Group were significantly shorter than in the ACB Group (95%CI: [− 0.78, − 0.16], P: 0.003). No difference was found between the patients in the ACB + iPACK Group and ACB Group on postoperative quadriceps muscle strength and the incidence of PONV.

Conclusion

The addition of iPACK lowers postoperative VAS scores, cumulative morphine consumption, and hospital stays. Meanwhile, the addition of iPACK improves postoperative patients’ activity performance without extra side effects. iPACK combined with ACB proves to be a suitable pain management technique after TKA.

Early Postoperative Pain Control and Inflammation for Total Knee Arthroplasty: A Retrospective Comparison of Continuous Adductor Canal Block versus Single-Shot Adductor Canal Block Combined with Patient-Controlled Intravenous Analgesia

Objective

The aim of this study was to compare pain control and inflammation among patients who received a continuous adductor canal block (CACB) versus single-shot adductor canal block (SACB) combined with patient-controlled intravenous analgesia (PCIA) for total knee arthroplasty (TKA) analgesia in the first two days after surgery.

Design

Matched cohort retrospective study. Setting. University hospital. Patients. One hundred fifty-six patient charts were included in this study: 78 patients with CACB in Group A and 78 patients with SACB combined with PCIA in Group B. Patients were matched according to age, body mass index, and American Society of Anesthesiologists class. Measurements. The primary outcome of the study was Visual Analogue Scale (VAS) pain scores before operation (Pre) and at postoperative 6 (POH6), 12 (POH12), 24 (POH24), 30 (POH30), 36 (POH36), and 48 hours (POH48). Secondary outcomes included patient-controlled bolus, time of first postoperative ambulation, range of knee flexion and extension, inflammation cytokines on Pre and POH48, percentage of remedial analgesics treatment, incidence of adverse events and complications, hospital stay and cost, and Numerical Rating Scale (NRS) satisfaction scores at discharge. Main Results. Mean VAS scores at rest and with motion were lower in Group B than in Group A on all postoperative hours. At POH30, compared with Group A (1.1 ± 0.6), mean VAS scores at rest in Group B (0.9 ± 0.4) were lower (P=0.048), and compared with Group A (2.6 ± 0.7), mean VAS scores with motion in Group B (2.2 ± 0.8) were lower (P=0.001). The number of patient-controlled bolus was 4.3 ± 1.6 (95% CI 3.9-4.6) in Group A and 3.1 ± 1.3 (95% CI 2.8-3.4) in Group B, respectively (P < 0.001). Patients in Group B displayed better functional recovery and inflammation results at POH48 than Group A with respect to range of knee flexion and extension (117.8 ± 10.9° vs. 125.2 ± 9.4°, P < 0.001) and inflammation cytokines, including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and interleukin-6 (IL-6) ((43.8 ± 16.1) vs. (36.8 ± 13.2), P=0.003; (34.9 ± 9.4 mg/L) vs. (29.6 ± 10.6 mg/L), P=0.001; (21.3 ± 8.7 pg/ml) vs. (14.0 ± 7.0 pg/ml), P < 0.001)).

Conclusion

SACB combined with PCIA in the first two days of patients undergoing TKA has better analgesic and beneficial effects on functional recovery and inflammation.

Analgesia effects of IPACK block added to multimodal analgesia regiments after total knee replacement: A systematic review of the literature and meta-analysis of 5 randomized controlled trials

BACKGROUND

Currently, no meta-analysis exists elucidate the analgesic effect of adding IPACK block to our current multimodal analgesia regimen after total knee replacement (TKR). The purpose of this study is to systematically review the level I evidence in the literature to ascertain whether IPACK block can bring additional analgesic benefits to existing multimodal analgesia regimens.

METHODS

The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Only level I randomized controlled trials (RCTs) were included in our study. The primary outcome was the pain scores with rest and activity. Secondary outcomes included cumulative opioid consumption, cumulative distance ambulated, and length of stay (LOS).

RESULTS

Five RCTs with a total of 467 patients were included. The most important finding in our study was that although IPACK block supplementation improved pain scores at 12 hours with rest or activity after surgery, no such benefit was observed at subsequent time points during the postoperative period. Interestingly, IPACK supplementation did not reduce opioid consumption, especially in the first 24 hours after surgery. Furthermore, other postoperative outcomes, including cumulative distance ambulated and LOS, were also not improved by the addition of an IPACK.

CONCLUSIONS

The addition of an IPACK block to multimodal analgesia regiments does not reduce the postoperative opioid consumption nor improve functional performance. However, it may be an appropriate method to improve immediate analgesic effects after TKR.

Infiltration between the popliteal artery and the capsule of the knee (IPACK) block in knee surgery: a narrative review

BACKGROUND

The infiltration between the popliteal artery and the capsule of the knee (IPACK) block has been described as an alternative analgesic strategy for knee pain.

OBJECTIVE

Our aim was to perform a narrative review to examine the place and value that the IPACK block has in comparison to and in conjunction with other regional anesthesia modalities.

EVIDENCE REVIEW

Following an extensive search of electronic databases, we included anatomical studies, letters, comparative observational studies, and non-randomized and randomized controlled trials that examined the IPACK block in relation to surgery on the knee under general or neuraxial anesthesia.

FINDINGS

In all, 35 articles were included. Cadaveric studies demonstrated the potential for injected dye to spread to the nerves responsible for the innervation of the posterior as well as anteromedial and anterolateral aspects of the knee. Of the comparative observational studies (n=15) and non-randomized (n=1) and randomized controlled trials (n=13), 2 and 27 were conducted in the context of anterior cruciate ligament reconstruction and knee replacement surgery, respectively. The role of the IPACK block with each different permutation of regional anesthesia techniques was investigated by a small number of studies. Clinical studies, in the setting of knee replacement surgery, revealed variation in the manner in which the IPACK block was performed, and indicated the possible superiority of distal injection at the level of the femoral condyles for the management of posterior knee pain. Evidence suggested the following: the IPACK block in combination with single shot adductor canal block (ACB) may be beneficial for analgesic and functional outcomes; in conjunction with single shot or continuous ACB, the IPACK block might be superior to local infiltration analgesia (LIA); and functional outcomes may be improved with the supplementation of continuous ACB and LIA with the IPACK block. The IPACK block did not commonly result in the occurrence of foot drop. Relative to tibial nerve block (TNB), the IPACK block reduced the occurrence of foot drop and increased the proportion of patients who were able to be discharged on the third postoperative day.

CONCLUSIONS

The IPACK block was potentially complementary to the ACB and might be preferable to the TNB as a motor-sparing regional anesthesia technique in knee surgery. Definitive recommendations were not reached in the presence of the heterogeneous and limited evidence base.

Does the addition of iPACK to adductor canal block in the presence or absence of periarticular local anesthetic infiltration improve analgesic and functional outcomes following total knee arthroplasty? A systematic review and meta-analysis

BACKGROUND

When combined with adductor canal block (ACB), local anesthetic infiltration between popliteal artery and capsule of knee (iPACK) is purported to improve pain following total knee arthroplasty (TKA). However, the analgesic benefits of adding iPACK to ACB in the setting of surgeon-administered periarticular local infiltration analgesia (LIA) are unclear.

OBJECTIVES

To evaluate the analgesic benefits of adding iPACK to ACB, compared with ACB alone, in the setting of LIA following TKA.

EVIDENCE REVIEW

We conducted a meta-analysis of randomized trials comparing the effects of adding iPACK block to ACB versus ACB alone on pain severity at 6 hours postoperatively in adult patients undergoing TKA. We a priori planned to stratify analysis for use of LIA. Opioid consumption at 24 hours, functional recovery, and iPACK-related complications were secondary outcomes.

FINDINGS

Fourteen trials (1044 patients) were analyzed. For the primary outcome comparison in the presence of LIA (four trials, 273 patients), adding iPACK to ACB did not improve postoperative pain at 6 hours. However, in the absence of LIA (eight trials, 631 patients), adding iPACK to ACB reduced pain by a weighted mean difference (WMD) (95% CI) of -1.33 cm (-1.57 to -1.09) (p<0.00001). For the secondary outcome comparisons in the presence of LIA, adding iPACK to ACB did not improve postoperative pain at all other time points, opioid consumption or functional recovery. In contrast, in the absence of LIA, adding iPACK to ACB reduced pain at 12 hours, and 24 hours by a WMD (95% CI) of -0.98 (-1.79 to -0.17) (p=0.02) and -0.69 (-1.18 to -0.20) (p=0.006), respectively, when compared with ACB alone, but did not reduce opioid consumption. Functional recovery was also improved by a log(odds ratio) (95% CI) of 1.28 (0.45 to 2.11) (p=0.003). No iPACK-related complications were reported.

CONCLUSION

Adding iPACK to ACB in the setting of periarticular LIA does not improve analgesic outcomes following TKA. In the absence of LIA, adding iPACK to ACB reduces pain up to 24 hours and enhances functional recovery. Our findings do not support the addition of iPACK to ACB when LIA is routinely administered.

Ultrasound-Guided Local Anesthetic Infiltration Between the Popliteal Artery and the Capsule of the Posterior Knee (IPACK) Block for Primary Total Knee Arthroplasty: A Systematic Review of Randomized Controlled Trials

Posterior knee pain after total knee arthroplasty (TKA) is common despite multimodal analgesia and regional anesthesia use. This review included randomized controlled trials (RCTs) comparing analgesic outcomes after inclusion of local anesthetic infiltration between the popliteal artery and capsule of the knee (iPACK) block versus pathways without iPACK. Electronic databases (MEDLINE, Cochrane Library, Web of Science, Scopus) were searched from inception to 10/11/2020. Eligible studies evaluated iPACK use on primary outcomes: opioid consumption and pain scores with movement. Secondary outcomes included rest pain, patient satisfaction, length of stay (LOS), gait distance, knee range of motion (ROM), and complications. Bias and quality were appraised using the Cochrane Risk of Bias tool and Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) guidelines. Eight RCTs (777 patients) were included. iPACK block use demonstrated similar opioid consumption in the PACU (4/7 RCTs) and 24 hours after TKA (5/7 RCTs) compared to without iPACK (moderate-quality GRADE evidence). Additionally, iPACK block use demonstrated lower movement pain scores in PACU (3/5 RCTs) but similar or higher pain scores after 24 hours (5/7 RCTs; low-quality GRADE evidence). Studies consistently reported no difference in gait distance (4/4 RCTs) or complications (7/7 RCTs) between treatment arms (high-quality GRADE evidence), although differing effect estimates were observed with resting pain, satisfaction, LOS, and knee ROM. This review provides a foundation of knowledge on iPACK efficacy. While evidence does not currently support widespread inclusion of iPACK within enhanced recovery pathways for TKA, limitations suggest further study is warranted.