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

Effects of Periarticular Multimodal Drug Injection on Pain Control, Early Mobilization, and Length of Hospital Stay in Patients Undergoing Total Knee Arthroplasty

We investigated the effects of periarticular multimodal drug injection (PMDI) on postoperative pain control, patients' mobilization, and length of hospital stay in patients undergoing total knee arthroplasty (TKA). We retrospectively enrolled patients who underwent unilateral TKA between 2019 and 2020. The formula for PMDI included 0.5 mL epinephrine (1 mg/mL), 1 mL ketorolac (30 mg/mL), 0.5 mL morphine (10 mg/mL), and 20 mL bupivacaine hydrochloride (5 mg/mL), mixed with 60 mL normal saline. The outcomes of interest included (1) the amount of patient-controlled anesthesia (PCA) consumption in the first 24 h after the surgery, (2) early mobilization within 24 h after the surgery, and (3) the length of hospital stay. A total of 127 patients were analyzed. Compared with patients who did not receive PMDI, those who received PMDI had lower consumption of PCA in the first 24 h (β coefficient -29.9, 95% CI -51.9 to -7.9, p = 0.008), higher odds of early mobilization within 24 h (odds ratio 8.263, 95% CI 3.041 to 22.453, p < 0.001), and shorter length of hospital stay (β coefficient -0.705, 95% CI -1.158 to -0.252, p = 0.003). We suggest that PMDI may be considered for patients undergoing TKA to improve the quality of care and shorten their length of hospital stay.

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.

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.

Association of peri-operative prescription of non-steroidal anti-inflammatory drugs with continued prescription of opioids after total knee arthroplasty: a retrospective claims-based cohort study

Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the mainstays of multimodal pain management. While effective for acute pain control, recent pre-clinical evidence has raised concerns regarding an association between NSAIDs and chronic pain and potential opioid use. Our objective was to explore the association between peri-operative use of prescription NSAIDs and the need for continued opioid prescriptions lasting 90-180 days in previously opioid-naïve patients undergoing total knee arthroplasty. A database of health claims in the USA was used to identify all opioid-naïve adult patients who underwent primary knee arthroplasty between January 2010 and October 2021. We evaluated the magnitude of association between peri-operative prescription NSAID claims and claims for opioids at 90 days postoperatively using multivariable logistic regression models. Secondary outcomes included: the magnitude of association between peri-operative NSAID prescription and claims for opioids at 180 days postoperatively; and identifying other potential factors associated with opioid claims at 90 days postoperatively. After risk adjustment using multivariable logistic regression models in the 789,736-patient cohort, the adjusted odds ratio (95%CI) for a continuous claim of opioids at 90 and 180 days postoperatively among patients with a peri-operative NSAID prescription within 30 days was 1.32 (1.30-1.35), p < 0.001; and 1.12 (1.10-1.15), p < 0.001, respectively. This estimate of effect remained robust at 90 days after accounting for known potential confounders, including pre-existing knee pain and acute postoperative pain severity. Similar analysis of other pain medications (e.g. paracetamol) did not detect such an association. This population-based cohort study suggests that peri-operative prescription NSAID use may be associated with continued opioid prescription claims at 90 and 180 days after knee arthroplasty, even after adjusting for other observed covariates for continuous opioid claims. These novel findings can inform clinical decision-making for post-surgical pain management, risk-benefit discussions with patients and future research.

Systematic reviews and meta-analyses in regional anesthesia and pain medicine (Part I): guidelines for preparing the review protocol

Comprehensive resources exist on how to plan a systematic review and meta-analysis. The objective of this article is to provide guidance to authors preparing their systematic review protocol in the fields of regional anesthesia and pain medicine. The focus is on systematic reviews of healthcare interventions, with or without an aggregate data meta-analysis. We describe and discuss elements of the systematic review methodology that review authors should prespecify, plan, and document in their protocol before commencing the review. Importantly, authors should explain their rationale for planning their systematic review and describe the PICO framework-participants (P), interventions (I),comparators (C), outcomes (O)-and related elements central to constructing their clinical question, framing an informative review title, determining the scope of the review, designing the search strategy, specifying the eligibility criteria, and identifying potential sources of heterogeneity. We highlight the importance of authors defining and prioritizing the primary outcome, defining eligibility criteria for selecting studies, and documenting sources of information and search strategies. The review protocol should also document methods used to evaluate risk of bias, quality (certainty) of the evidence, and heterogeneity of results. Furthermore, the authors should describe their plans for managing key data elements, the statistical construct used to estimate the intervention effect, methods of evidence synthesis and meta-analysis, and conditions when meta-analysis may not be possible, including the provision of practical solutions. Authors should provide enough detail in their protocol so that the readers could conduct the study themselves.

What Is the Role of a Periarticular Injection for Knee Arthroplasty Patients Receiving a Multimodal Analgesia Regimen Incorporating Adductor Canal and Infiltration Between the Popliteal Artery and Capsule of the Knee Blocks? A Randomized Blinded Placebo-Controlled Noninferiority Trial

BACKGROUND

Optimal analgesic protocols for total knee arthroplasty (TKA) patients remain controversial. Multimodal analgesia is advocated, often including peripheral nerve blocks and/or periarticular injections (PAIs). If 2 blocks (adductor canal block [ACB] plus infiltration between the popliteal artery and capsule of the knee [IPACK]) are used, also performing PAI may not be necessary. This noninferiority trial hypothesized that TKA patients with ACB + IPACK + saline PAI (sham infiltration) would have pain scores that were no worse than those of patients with ACB + IPACK + active PAI with local anesthetic.

METHODS

A multimodal analgesic protocol of spinal anesthesia, ACB and IPACK blocks, intraoperative ketamine and ketorolac, postoperative ketorolac followed by meloxicam, acetaminophen, duloxetine, and oral opioids was used. Patients undergoing primary unilateral TKA were randomized to receive either active PAI or control PAI. The active PAI included a deep injection, performed before cementation, of bupivacaine 0.25% with epinephrine, 30 mL; morphine; methylprednisolone; cefazolin; with normal saline to bring total volume to 64 mL. A superficial injection of 20 mL bupivacaine, 0.25%, was administered before closure. Control injections were normal saline injected with the same injection technique and volumes. The primary outcome was numeric rating scale pain with ambulation on postoperative day 1. A noninferiority margin of 1.0 was used.

RESULTS

Ninety-four patients were randomized. NRS pain with ambulation at POD1 in the ACB + IPACK + saline PAI group was not found to be noninferior to that of the ACB + IPACK + active PAI group (difference = 0.3, 95% confidence interval [CI], [-0.9 to 1.5], P = .120). Pain scores at rest did not differ significantly among groups. No significant difference was observed in opioid consumption between groups. Cumulative oral morphine equivalents through postoperative day 2 were 89 ± 40 mg (mean ± standard deviation), saline PAI, vs 73 ± 52, active PAI, P = .1. No significant differences were observed for worst pain, fraction of time in severe pain, pain interference, side-effects (nausea, drowsiness, itching, dizziness), quality of recovery, satisfaction, length of stay, chronic pain, and orthopedic outcomes.

CONCLUSIONS

For TKA patients given a comprehensive analgesic protocol, use of saline PAI did not demonstrate noninferiority compared to active PAI. Neither the primary nor any secondary outcomes demonstrated superiority for active PAI, however. As we cannot claim either technique to be better or worse, there remains flexibility for use of either technique.

Ambulatory total hip and knee arthroplasty: a literature review and perioperative considerations

PURPOSE

Total joint arthroplasty (TJA), particularly for the hip and knee, is one of the most commonly performed surgical procedures. The advancement/evolution of surgical and anesthesia techniques have allowed TJA to be performed on an ambulatory/same-day discharge basis. In this Continuing Professional Development module, we synthesize the perioperative evidence that may aid the development of successful ambulatory TJA pathways.

SOURCE

We searched MEDLINE, Embase, CENTRAL, and the Cochrane Database of Systematic Reviews for ambulatory or fast-track TJA articles. In the absence of direct evidence for the ambulatory setting, we extrapolated the evidence from the in-patient TJA literature.

PRINCIPAL FINDINGS

Patient selection encompassing patient, medical, and social factors is fundamental for successful same-day discharge of patients following TJA. Evidence for the type of intraoperative anesthesia favours neuraxial technique for achieving same day discharge criteria and reduced perioperative complications. Availability of short-acting local anesthetic for neuraxial anesthesia would affect the anesthetic choice. Nonetheless, modern general anesthesia with multimodal analgesia and antithrombotics in a well selected population can be considered. Regional analgesia forms an integral part of the multimodal analgesia regime to reduce opioid consumption and facilitate same-day hospital discharge, reducing hospital readmission. For ambulatory total knee arthroplasty, a combination of adductor canal block with local anesthetic periarticular infiltration provided is a suitable regional analgesic regimen.

CONCLUSION

Anesthesia for TJA has evolved as such that same-day discharge will become the norm for selected patients. It is essential to establish pathways for early discharge to prevent adverse effects and readmission in this population. As more data are generated from an increased volume of ambulatory TJA, more robust evidence will emerge for the ideal anesthetic components to optimize outcomes.

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.

Investigation of Optimal Needle Position for Radiofrequency Ablation-Based Blockade of Interspace between the Popliteal Artery and the Posterior Capsule of the Knee: A Cadaveric Study

Background and Objectives: The interspace between the popliteal artery and the posterior capsule of the knee (iPACK) block has been widely used in perioperative settings to control posterior knee pain and can additionally be used for chronic knee pain. In this cadaveric study, we aimed to investigate the needle tip position and its proximity to the articular branch of the tibial nerve (ABTN) during an iPACK-targeted radiofrequency procedure. Materials and Methods: An ultrasound-guided iPACK block was performed on 20 knees of 10 cadavers. We injected 0.1 mL each of blue and green gelatinous dye near the tibial artery (point A) and posterior knee capsule (point B), respectively, and evaluated the spread of both around the ABTN. For a hypothetical conventional radiofrequency ablation (RFA) lesion (diameter, 2.95 mm) and cooled RFA lesion (diameter, 4.9 mm), we counted the number of specimens in which the ABTNs would be captured. Results: The percentage of specimens in which the ABTN would be captured by a cooled RFA lesion was 64.71% at point A and 43.75% at point B (p = 0.334). Meanwhile, the percentage of specimens in which the ABTN would be captured by a conventional RFA lesion was 58.82% from point A and 25% from point B (p = 0.065). Conclusions: When performing an RFA-based iPACK block, the needle tip may be positioned either lateral to the tibial artery or in the space between the posterior knee capsule and the tibial artery. However, more studies with larger samples are needed to verify these results before the clinical use of this procedure can be recommended.

Combined Single-Shot Infiltration Between the Popliteal Artery and Capsule of the Knee and Adductor Canal Block With Bupivacaine, Dexmedetomidine, and Dexamethasone for Total Knee Arthroplasty: A Propensity-Matched Analysis

Background

To investigate if combined single-shot adductor canal blockade (ACB) and infiltration between the popliteal artery and capsule of the knee (IPACK) provide better postoperative pain management compared to ACB alone for patients undergoing unilateral total knee arthroplasty (TKA).

Methods

This retrospective cohort study included adult patients who underwent primary, unilateral TKA. Patients were separated into 2 cohorts: single-shot ACB alone (performed with bupivacaine 0.25%) and combined single-shot ACB + IPACK (performed with bupivacaine 0.25%, dexmedetomidine 1 mg/kg, and dexamethasone 4 mg). Patients were propensity-matched 1:1. The primary study outcome was total opioid consumption converted to morphine milligram equivalents (MME) per eight-hour interval and postoperative day. Secondary outcomes included pain scores, length of stay, ambulation distance, return to emergency department, hospital readmission, and 30-day adverse events.

Results

One hundred eighty patients were identified, of which propensity matching used 71% to yield 64 patients receiving ACB alone and 64 receiving combined ACB + IPACK. Combined ACB + IPACK had significantly lower total summative MME throughout the entire postoperative stay (P = .002) and cumulatively after the first 24 hours (P < .001). Combined ACB + IPACK also had lower mean pain scores for 0-8 hours (P = .005) and 8-16 hours (P = .009) postoperatively. There were no significant differences in secondary outcomes.

Conclusions

Combined single-shot ACB + IPACK block was associated with lower total narcotic intake and mean pain scores during most of the immediate postoperative period following primary, unilateral TKA compared to ACB alone. Implementing longer-acting, single-shot ACB + IPACK for TKA can balance effective and more selective pain management with early rehabilitation.

Systematic Reviews and Meta-analyses in Regional Anesthesia and Pain Medicine (Part I): Guidelines for Preparing the Review Protocol

Comprehensive resources exist on how to plan a systematic review and meta-analysis. The objective of this article is to provide guidance to authors preparing their systematic review protocol in the fields of regional anesthesia and pain medicine. The focus is on systematic reviews of health care interventions, with or without an aggregate data meta-analysis. We describe and discuss elements of the systematic review methodology that review authors should prespecify, plan, and document in their protocol before commencing the review. Importantly, authors should explain their rationale for planning their systematic review and describe the PICO framework-participants (P), interventions (I), comparators (C), outcomes (O)-and related elements central to constructing their clinical question, framing an informative review title, determining the scope of the review, designing the search strategy, specifying the eligibility criteria, and identifying potential sources of heterogeneity. We highlight the importance of authors defining and prioritizing the primary outcome, defining eligibility criteria for selecting studies, and documenting sources of information and search strategies. The review protocol should also document methods used to evaluate risk of bias, quality (certainty) of the evidence, and heterogeneity of results. Furthermore, the authors should describe their plans for managing key data elements, the statistical construct used to estimate the intervention effect, methods of evidence synthesis and meta-analysis, and conditions when meta-analysis may not be possible, including the provision of practical solutions. Authors should provide enough detail in their protocol so that the readers could conduct the study themselves.

Chronic post-surgical pain after knee arthroplasty: a role of peripheral nerve blocks

Introduction

Peripheral nerve blocks are an efficient method of pain control after total knee arthroplasty (TKA), but there is no report of their impact on chronic post-surgical pain (CPSP).

Methods

This prospective observational study aimed to assess adductor canal block (ACB) and IPACK block (blocks vs. no blocks) on opioid consumption, postoperative pain score, chronic post-surgical pain 2 years after TKA.

Results

166 patients (82 vs. 84) were analyzed. Opioid consumption was less in the group with blocks (9.74 ± 3.87 mg vs. 30.63 ± 11.52 mg) (p < 0.001). CPSP was present in 20.24% of patients in the group without blocks and 6.1% of patients with blocks (p = 0.011). Predictor variables of CPSP included pain before surgery (cut-off of 5.5), pain at rest (cut-off of 2.35), pain during active movement (cut-off: 2.5), and opioid consumption (cut-off: 8 mg).

Conclusion

Peripheral nerve blocks provide adequate analgesia, significantly decrease opioid consumption, improve functional outcomes, and reduce CPSP 2 years after surgery.

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.

Analgesic Effectiveness of Motor-sparing Nerve Blocks for Total Knee Arthroplasty: A Network Meta-analysis

BACKGROUND

The analgesic effectiveness of contemporary motor-sparing nerve blocks used in combination for analgesia in total knee arthroplasty is unclear. This network meta-analysis was conducted to evaluate the analgesic effectiveness of adding single-injection or continuous adductor canal block (ACB) with or without infiltration of the interspace between the popliteal artery and the capsule of the posterior knee (iPACK) to intraoperative local infiltration analgesia (LIA), compared to LIA alone, after total knee arthroplasty.

METHODS

Randomized trials examining the addition of single-injection or continuous ACB with or without single-injection block at the iPACK to LIA for total knee arthroplasty were considered. The two primary outcomes were area-under-the-curve pain scores over 24 to 48 h and postoperative function at greater than 24 h. Secondary outcomes included rest pain scores at 0, 6, 12, and 24 h; opioid consumption (from 0 to 24 h and from 25 to 48 h); and incidence of nausea/vomiting. Network meta-analysis was conducted using a frequentist approach.

RESULTS

A total of 27 studies (2,317 patients) investigating the addition of (1) single-injection ACB, (2) continuous ACB, (3) single-injection ACB and single-injection block at the iPACK, and (4) continuous ACB and single-injection block at the iPACK to LIA, as compared to LIA alone, were included. For area-under-the-curve 24- to 48-h pain, the addition of continuous ACB with single-injection block at the iPACK displayed the highest P-score probability (89%) of being most effective for pain control. The addition of continuous ACB without single-injection block at the iPACK displayed the highest P-score probability (87%) of being most effective for postoperative function.

CONCLUSIONS

The results suggest that continuous ACB, but not single-injection ACB and/or single-injection block at the iPACK, provides statistically superior analgesia when added to LIA for total knee arthroplasty compared to LIA alone. However, the magnitude of these additional analgesic benefits is clinically questionable.

EDITOR’S PERSPECTIVE

Analgesic Trends in the Management of Pain Following Total Knee Arthroplasty: A Comparison of Peri-Articular Infiltration, Adductor Canal Block, and Adjuvant Treatment for Posterior Knee Pain

The rising number of total knee arthroplasties (TKA's) in the United States increases demand for perioperative pain modalities, which can promote early mobilization and discharge. Over the decades, a focus has shifted from opioid-dominant regimens to motor-sparing multimodal protocols, which have not only improved pain scores and reduced opioid consumption but also improved overall patient outcomes. In this article, we briefly review the evolution of post-operative pain management in patients undergoing TKA and summarize the literature on the most popular modalities currently used including periarticular injections, adductor canal blocks, distal selective nerve blocks, as well as liposomal bupivacaine as part of a multimodal approach.

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.

Comparison of Analgesic Efficacies of the iPACK (Interspace Between the Popliteal Artery and Capsule of the Posterior Knee) and Genicular Nerve Blocks Used in Combination With the Continuous Adductor Canal Block After Total Knee Arthroplasty: A Randomized Clinical Trial

BACKGROUND

The interspace between the popliteal artery and capsule of the posterior knee (iPACK) block and the genicular nerve block (GNB) are motor-sparing nerve blocks used for knee pain relief. We compared the analgesic efficacies of ultrasound-guided iPACK block and GNB when combined with continuous adductor canal block after total knee arthroplasty.

METHODS

In this randomized control study, 132 total knee arthroplasty patients were assigned to the iPACK, GNB, and iPACK + GNB groups. All patients received combined spinal anesthesia and continuous adductor canal block. The primary outcome was the 8-hour postoperative pain score during movement. Secondary outcomes were pain scores, posterior knee pain, intravenous morphine consumption, and tibial and common peroneal nerve sensorimotor function. All included patients completed the study.

RESULTS

The 4-hour and 8-hour postoperative pain scores during movement were significantly lower in the iPACK + GNB group than that in the iPACK group (-2.5 [3.6, 1.3]; P < .001 and -2 [-3, -1]; P < .001, respectively). The differences in rating pain scores and posterior knee pain were not clinically relevant. The iPACK group demonstrated a significantly higher intravenous morphine consumption than did the GNB and iPACK + GNB groups during the first 48 hours postoperatively (P < .001) but were not clinically relevant. There was no incidence of complete sensorimotor blockade in any of the groups.

CONCLUSION

The iPACK-GNB combination relieved pain during movement better than the iPACK block alone during the 8 hours postoperatively after total knee arthroplasty in setting of multimodal analgesia such as adductor canal block.

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.

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

In this Pro-Con commentary article, we debate the importance of anterior thigh block locations for analgesia following total knee arthroplasty. The debate is based on the current literature, our understanding of the relevant anatomy, and a clinical perspective. We review the anatomy of the different fascial compartments, the course of different nerves with respect to the fascia, and the anatomy of the nerve supply to the knee joint. The Pro side of the debate supports the view that more distal block locations in the anterior thigh increase the risk of excluding the medial and intermediate cutaneous nerves of the thigh and the nerve to the vastus medialis, while increasing the risk of spread to the popliteal fossa, making distal femoral triangle block the preferred location. The Con side of the debate adopts the view that while the exact location of local anesthetic injection appears anatomically important, it has not been proven to be clinically relevant.

No Benefit of Adductor Canal Block Compared with Anterior Local Infiltration Analgesia in Primary Total Knee Arthroplasty: A Single-Blinded Randomized Controlled Clinical Trial

BACKGROUND

An adductor canal block (ACB) performed by an anesthesiologist is an established component of analgesia after total knee arthroplasty. Alternatively, surgeons may perform periarticular local infiltration analgesia (LIA) intraoperatively. We hypothesized that ACB would be superior to anterior LIA in terms of morphine consumption in the first 48 hours after primary total knee arthroplasty under spinal anesthesia.

METHODS

This prospective controlled and blinded trial included 98 patients; 48 received an ACB plus sham (saline solution) anterior LIA, and 50 received a sham (saline solution) ACB plus anterior LIA. Both groups received posterior LIA with local anesthetic. The primary outcome was cumulative morphine consumption at 48 hours after surgery. Secondary outcomes were pain while resting, standing, and walking, rehabilitation scores, opioid-related side effects, and patient satisfaction.

RESULTS

No difference in the primary outcome was found, and the 48-hour morphine consumption was low in both arms (28.8 ± 17.6 mg with ACB, 26.8 ± 19.2 mg with anterior LIA; p = 0.443). Pain scores were significantly better in the anterior LIA arm, but the differences were not clinically relevant. There were no differences in any other secondary outcome measures.

CONCLUSIONS

LIA may be used as the primary option for multimodal postoperative pain management in patients undergoing primary total knee arthroplasty with spinal anesthesia.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

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.

Motor-sparing peripatellar plexus block provides noninferior block duration and complete block area of the peripatellar region compared with femoral nerve block: a randomized, controlled, noninferiority study

BACKGROUND

Developing adequate regional anaesthesia for knee surgeries without affecting lower limb mobilization is crucial to perioperative analgesia. However, reports in this regard are limited. We proposed a technique for ultrasound-guided peripatellar plexus (PP) block. Compared with the femoral nerve (FN) block, we hypothesized that this technique would provide a noninferior block duration and a complete cutaneous sensory block in the peripatellar region without affecting lower limb mobilization. An investigation was conducted to verify our hypothesis in cadavers and volunteers.

METHODS

The study was designed in two parts. First, eight cadaveric lower limbs were dissected to verify the feasibility of PP block after methylene blue injection under ultrasound. Second, using a noninferiority study design, 50 healthy volunteers were randomized to receive either a PP block (PP group) or an FN block (FN group). The primary outcome was the duration of peripatellar cutaneous sensory block, with the prespecified noninferiority margin of -3.08 h; the secondary outcome was the area of peripatellar cutaneous sensory block; in addition, the number of complete anaesthesias of the incision line for total knee arthroplasty and the Bromage score 30 min after block were recorded.

RESULTS

The PP was successfully dyed, whereas the FN and saphenous nerve were unstained in all cadaveric limbs. The mean difference of the block duration between the two groups was - 1.24 (95% CI, -2.81 - 0.33) h, and the lower boundary of the two-sided 95% CI was higher than the prespecified noninferiority margin (P_{noninferiority} = 0.023), confirming the noninferiority of our technique over FN block. The cutaneous sensory loss covered the entire peripatellar region in the PP group. PP block achieved complete anaesthesia of the incision line used for total knee arthroplasty and a Bromage score of 0 in 25 volunteers, which differed significantly from that of volunteers who underwent FN block.

CONCLUSION

Ultrasound-guided PP block is a feasible technique. Compared with FN block, PP block provides noninferior block duration and complete blocking of the peripatellar region without affecting lower limb mobilization.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trial Register (registration no. ChiCTR2000041547, registration date 28/12/2020).

Pain management after total knee arthroplasty: PROcedure SPEcific Postoperative Pain ManagemenT recommendations

BACKGROUND

The PROSPECT (PROcedure SPEcific Postoperative Pain ManagemenT) Working Group is a global collaboration of surgeons and anaesthesiologists formulating procedure-specific recommendations for pain management after common operations. Total knee arthroplasty (TKA) is associated with significant postoperative pain that is difficult to treat. Nevertheless, pain control is essential for rehabilitation and to enhance recovery.

OBJECTIVE

To evaluate the available literature and develop recommendations for optimal pain management after unilateral primary TKA.

DESIGN

A narrative review based on published systematic reviews, using modified PROSPECT methodology.

DATA SOURCES

A literature search was performed in EMBASE, MEDLINE, PubMed and Cochrane Databases, between January 2014 and December 2020, for systematic reviews and meta-analyses evaluating analgesic interventions for pain management in patients undergoing TKA.

ELIGIBILITY CRITERIA

Each randomised controlled trial (RCT) included in the selected systematic reviews was critically evaluated and included only if met the PROSPECT requirements. Included studies were evaluated for clinically relevant differences in pain scores, use of nonopioid analgesics, such as paracetamol and nonsteroidal anti-inflammatory drugs and current clinical relevance.

RESULTS

A total of 151 systematic reviews were analysed, 106 RCTs met PROSPECT criteria. Paracetamol and nonsteroidal anti-inflammatory or cyclo-oxygenase-2-specific inhibitors are recommended. This should be combined with a single shot adductor canal block and peri-articular local infiltration analgesia together with a single intra-operative dose of intravenous dexamethasone. Intrathecal morphine (100 μg) may be considered in hospitalised patients only in rare situations when both adductor canal block and local infiltration analgesia are not possible. Opioids should be reserved as rescue analgesics in the postoperative period. Analgesic interventions that could not be recommended were also identified.

CONCLUSION

The present review identified an optimal analgesic regimen for unilateral primary TKA. Future studies to evaluate enhanced recovery programs and specific challenging patient groups are needed.

Minimum effective concentration of ropivacaine for ultrasound-guided adductor canal + IPACK block in total knee arthroplasty

OBJECTIVE

This study aimed to investigate the minimum effective concentration (MEC_90, defined as effective in 90% of patients) of ropivacaine during the combined procedure of adductor canal block (ACB) and infiltration between the popliteal artery and capsule of the posterior knee (IPACK) block for patients undergoing total knee arthroplasty.

METHODS

This double-blind, randomized dose-finding trial was based on a biased coin up-and-down sequential design, where the concentration of ropivacaine administered to a given patient depended on the previous patient's response. Before surgery, the first patient received 20 mL of 0.2% ropivacaine for ACB and again for IPACK. If the block failed, the next subject received a 0.025% higher ropivacaine concentration; otherwise, the next subject received either a 0.025% smaller dose (probability of 0.11) or the same dose (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. MEC₉₀ was estimated by isotonic regression, and the 95% confidence interval (CI) was calculated by bootstrapping. Secondary outcomes were numerical rating scale (NRS) pain scores at postoperative 24 h and 48 h, postoperative morphine consumption, and time to hospital discharge. Secondary outcomes were compared between patients whose blocks succeeded with those which failed.

RESULTS

Based on analysis of 52 patients, the MEC₉₀ was 0.247% (95% CI 0.227-0.271%), MEC₉₅ was 0.260% (95% CI 0.244-0.282%) and MEC₉₉ was 0.272% (95% CI 0.260-0.291%). In contrast, four of nine trials in a recent systematic review reported ropivacaine concentrations below 0.247%. Patients whose blocks succeeded (n = 45) had significantly lower NRS pain scores, lower morphine consumption, and shorter hospitalization than patients whose blocks failed (n = 7).

CONCLUSIONS

Our small trial suggests that 0.247% ropivacaine in 20 mL respectively can provide successful ACB + IPACK block in 90% of patients. However, given that many published trials have used lower concentrations, our findings should be verified in larger studies.

Analgesic benefits of the quadratus lumborum block in total hip arthroplasty: a systematic review and meta-analysis

The quadratus lumborum block (QLB) is reported to reduce pain and improve function following total hip arthroplasty; however, randomised controlled trials evaluating the benefits of adding this block to general or spinal anaesthesia in this population are conflicting. We performed a systematic review seeking randomised controlled trials investigating QLB benefits for total hip arthroplasty, stratifying comparisons regarding the addition of QLB to either general or spinal anaesthesia. The primary outcome was 24-h area under the curve (AUC) pain score. Pain scores were interpreted in the context of a population-specific minimal clinically important difference of 1.86 cm on a 10-cm visual analogue scale, or an AUC pain score of 5.58 cm.h. Secondary outcomes included analgesic consumption, functional recovery and opioid-related side-effects. In all, 18 trials (1318 patients) were included. Adding QLB to general or spinal anaesthesia improved 24-h AUC rest pain scores by a mean difference (95%CI) of -3.56 cm.h (-6.70 to -0.42; p = 0.034) and - 4.19 cm.h (-7.20 to -1.18; p = 0.014), respectively. These improvements failed to reach the pre-determined minimal clinically important difference, as did the reduction in analgesic consumption. Quadratus lumborum block improved functional recovery for general, but not spinal, anaesthesia. Opioid-related side-effects were reduced with QLB regardless of anaesthetic modality. Low-to-moderate quality evidence suggests that the extent to which adding QLB to either general or spinal anaesthesia reduces postoperative pain and opioid consumption after total hip arthroplasty is statistically significant but may be clinically unimportant for most patients. However, adding QLB to general anaesthesia might enhance functional recovery. Taken together, our findings do not support the routine use of QLB as part of multimodal analgesic regimens for total hip arthroplasty.

No Benefits of Adding Dexmedetomidine, Ketamine, Dexamethasone and Nerve Blocks to an Established Multimodal Analgesic Regimen after Total Knee Arthroplasty

BACKGROUND.

An optimal opioid-sparing multimodal analgesic regimen to treat severe pain can enhance recovery after total knee arthroplasty. We hypothesized that adding 5 recently described IV and regional interventions to multimodal analgesic regimen can further reduce opioid consumption.

METHODS.

In a double-blinded fashion, seventy-eight patients undergoing elective total knee arthroplasty were randomized to either (1) a control group (n=39) that received spinal anesthesia with intrathecal morphine, periarticular local anesthesia infiltration, IV dexamethasone and a single injection adductor canal block or (2) a study group (n=39) that received the same set of analgesic treatments plus 5 additional interventions - local anesthetic infiltration between the popliteal artery and capsule of the posterior knee, intraoperative IV dexmedetomidine and ketamine, and postoperatively, 1 additional IV dexamethasone bolus, and 2 additional adductor canal block injections. The primary outcome measure was 24-hour cumulative opioid consumption after surgery and secondary outcomes were other analgesic, patient recovery and functional outcomes and adverse events.

RESULTS.

Opioid consumption was not different between groups at 24 hours (oral morphine equivalents, mean ± SD), study: 23.7 ± 18.0 mg vs. control: 29.3 ± 18.7 mg; mean difference [95% CI], -5.6 mg [-2.7, 13.9]; P = 0.189) and all other time points after surgery. There were no major differences in pain scores, quality of recovery, or time to reach rehabilitation milestones. Hypotensive episodes occurred more frequently in the study group (25/39 (64.1%) vs. 13/39 (33.3%), p= 0.010).

CONCLUSIONS.

In the presence of periarticular local anesthesia infiltration, intrathecal morphine, single shot adductor canal block and dexamethasone, the addition of 5 analgesic interventions - local anesthetic infiltration between the popliteal artery and capsule of the posterior knee, IV dexmedetomidine, IV ketamine, an additional IV dexamethasone dose and repeated adductor canal block injections - failed to further reduce opioid consumption, pain scores or improve functional outcomes after total knee arthroplasty.

Adding Dexamethasone to Adductor Canal Block Combined with iPACK Block Improve Postoperative Analgesia of Total Knee Arthroplasty

OBJECTIVE

Both adductor canal block (ACB) and infiltration between the popliteal artery and capsule of knee (iPACK) block are mainly sensory blocks, preserved muscle strength and ability to ambulate. This study was designed to evaluate whether adding dexamethasone to ropivacaine could improve postoperative analgesia after total knee arthroplasty (TKA).

METHODS

This prospective double-blind randomized controlled trial included 60 patients who underwent unilateral TKA under general anesthesia. All patients who received ACB and iPACK block were randomly divided into a dexamethasone group (Group D, ropivacaine combined with dexamethasone) and a control group (Group C, ropivacaine only). The primary outcome was the time to first administration of rescue analgesic drugs. Secondary outcomes included the total amount of rescue analgesic drugs and the pain scores at different time points within 72 hours postoperatively; the time to first getting out of bed, quality of recovery scale (QOR-15 score), and the levels of plasma inflammatory markers (IL-6 and CRP) on postoperative day 1.

RESULTS

Compared with Group C, the time to first administration of rescue analgesic drugs of Group D was significantly extended by approximately 10.5 hours. Patients in Group D had significantly lower pain scores at postoperative different time points and consumed significantly smaller total morphine within 72 hours postoperatively. In addition, patients in group D reported significantly higher QoR-15 scores on postoperative days 1 and 3, earlier first time of getting out of bed, and significantly lower levels of CRP and IL-6 on postoperative day 1.

CONCLUSIONS

Compared with using ropivacaine alone, ultrasonic guided ACB combined with iPACK using ropivacaine and dexamethasone could prolong the duration of postoperative analgesia and strength analgesic intensity and promote the early rehabilitation exercise of patients undergoing TKA.

The effect of continuous adductor canal block combined with distal interspace between the popliteal artery and capsule of the posterior knee block for total knee arthroplasty: a randomized, double-blind, controlled trial

BACKGROUND

The optimal analgesia for total knee arthroplasty (TKA) requires excellent analgesia while preserving muscle strength. This study aimed to determine the hypothesis that continuous adductor canal block (CACB) combined with the distal interspace between the popliteal artery and the posterior capsule of the knee (IPACK) block could effectively alleviate the pain of the posterior knee, decrease opioids consumption, and promote early recovery and discharge.

METHODS

Patients undergoing unilateral, primary TKA were allocated into group CACB+SHAM (receiving CACB plus sham block) or group CACB+IPACK (receiving CACB plus IPACK block). The primary outcome was cumulative opioid consumption. Secondary outcomes included the incidence of postoperative pain originated from the posterior knee, visual analogue scale (VAS) score, range of motion, ambulation distance, and satisfaction for pain management.

RESULTS

The incidence of moderate-severe pain of the posterior knee was lower in group CACB+IPACK than that of the group CACB+SHAM at 4 hours (17.1% vs. 42.8%; p = 0.019), 8 hours (11.4% vs. 45.7%; p = 0.001), and 24 hours (11.4% vs. 34.3%; p = 0.046) after TKA. The VAS scores of the posterior knee were lower in group CACB+IPACK than that of the group CACB+SHAM at 4 hours [2 (2) vs. 3 (2-4); p = 0.000], 8 hours [1 (1, 2) vs. 3 (2-4); p = 0.001], and 24 hours [1(0-2) vs. 2 (1-4); p = 0.002] after TKA. The overall VAS scores were lower in group CACB+IPACK than that of the group CACB+SHAM at 4 hours [3 (2, 3) vs. 3 (3, 4); p = 0.013] and 8 hours [2 (2, 3) vs. 3 (2-4); p = 0.032] at rest and 4 hours [3 (3, 4) vs. 4 (4, 5); p = 0.001], 8 hours [3 (2-4) vs. 4 (3-5); p = 0.000], 24 hours [2 (2, 3) vs. 3 (2-4); p = 0.001] during active flexion after TKA. The range of motion (59.11 ± 3.90 vs. 53.83 ± 5.86; p = 0.000) and ambulation distance (44.60 ± 4.87 vs. 40.83 ± 6.65; p = 0.009) were superior in group CACB+IPACK than that of the group CACB+SHAM in postoperative day 1. The satisfaction for pain management was higher in group CACB+IPACK than that of the group CACB+SHAM [9 (8, 9) vs. 8 (7-9); p = 0.024]. There was no difference in term of cumulative opioids consumption between group CACB+IPACK and group CACB+SHAM [120(84-135) vs. 120(75-135); p = 0.835].

CONCLUSION

The combination of CACB and distal IPACK block could decrease the incidences of moderate-severe posterior knee pain, improve the postoperative pain over the first 24 hours after TKA, as well as promoting recovery of motor function. However, the opioids consumption was not decreased by adding distal IPACK to CACB.

TRIAL REGISTRATION

This study was registered at Chinese Clinical Trial Registry ( ChiCTR2200059139 ; registration date: 26/04/2022; enrollment date: 16/11/2020; http://www.chictr.org.cn ).

Optimal location for continuous catheter analgesia among the femoral triangle, proximal, or distal adductor canal after total knee arthroplasty: a randomized double-blind controlled trial

Background

Pain management after total knee arthroplasty is essential to improve early mobilization, rehabilitation, and recovery. Continuous adductor canal (AC) block provides postoperative analgesia while preserving quadriceps strength. However, there have been inconsistencies regarding the optimal location for continuous catheter block. We compared continuous femoral triangle, proximal AC, and distal AC blocks for postoperative analgesia after total knee arthroplasty.

Methods

Patients undergoing unilateral total knee arthroplasty were randomly assigned to three groups: femoral triangle, proximal AC, or distal AC. The surgeon performed periarticular local anesthetic infiltration. After surgery, an ultrasound-guided perineural catheter insertion procedure was performed. The primary endpoint was pain scores at rest in the morning on the first postoperative day. Secondary endpoints included pain scores at rest and during activity at other time points, quadriceps strength, and opioid consumption.

Results

Ninety-five patients, 32 in the femoral triangle group, 31 in the proximal AC group, and 32 in the distal AC group, completed the study. Analysis of the primary outcome showed no significant difference in pain scores among groups. Secondary outcomes showed significantly lower pain scores at rest and during activity in the distal AC group than in the femoral triangle and proximal AC groups in the morning of the second postoperative day. Quadriceps strength and opioid consumption did not differ among groups.

Conclusions

Continuous femoral triangle, proximal AC, and distal AC blocks in the setting of periarticular local anesthetic infiltration provide comparable postoperative analgesia after total knee arthroplasty.

Trial registration number

NCT04206150.

Effect of Early Electroacupuncture Combined with Enhanced Recovery after Surgery (ERAS) on Pain Perception and Dysfunction in Patients after Total Knee Arthroplasty (TKA)

Objective

A retrospective case-control study was performed to observe the effect and clinical significance of early electroacupuncture combined with enhanced recovery after surgery (ERAS) on pain perception and dysfunction after total knee arthroplasty (TKA).

Methods

About 100 patients who diagnosed with TKA from February 2019 to April 2021 were enrolled in our hospital. The patients were arbitrarily assigned into control group and study group. The former group was cured with electroacupuncture in the early stage, and the latter group was intervened on the basis of early electroacupuncture combined with the concept of ERAS. The curative effect, the time of getting out of bed for the first time after operation, the time of postoperative rehabilitation, postoperative rehabilitation cost, pain score and knee joint function score, range of motion (ROM) of knee joint, low shear of whole blood viscosity, plasma viscosity, fibrinogen level, and postoperative complications were compared.

Results

There exhibited no statistical difference in clinical data. In terms of the treatment effects, there were 27 cases of markedly effective, 22 cases of effective, and 1 case of ineffective in the study group, and the total effective rate was 98.00%; in the control group, 15 cases were markedly effective, 28 cases were effective, and 13 cases were ineffective, and the total effective rate was 86.00%. Compared to the control group, the total effective rate of the study group was higher (P < 0.05). And the first time to get out of bed and the postoperative rehabilitation time in the study group were lower. Compared to the control group (10113.42 ± 524.83) yuan, the postoperative rehabilitation cost in the study group (12401.71 ± 530.77) yuan was higher. In terms of the scores of VAS and HSS, there exhibited no remarkable difference before treatment (P > 0.05). After treatment, the VAS score lessened and the HSS score augmented the study group VAS score (1.76 ± 0.28); the score in the control group was lower compared to the control group (3.45 ± 0.36), and HSS scoring (83.48 ± 11.23) points higher compared to the control group (65.82 ± 10.44) points (P < 0.05). The ROM of knee joint augmented successively at the 1st, 2nd, 4th, and 8th week after treatment comparison between groups, the ROM of the knee joint in the study group at the 1st, 2nd, 4th, and 8th week was (49.47 ± 3.60)°, (64.38 ± 5.32)°, (86.93 ± 6.72)°, and (104.20 ± 9.11)°, is higher compared to the control group (46.53 ± 3.41)°, (61.52 ± 5.20)°, (78.42 ± 6.45)°, and (98.77 ± 8.67)° (P < 0.05). One day after operation, there exhibited no remarkable difference in whole blood viscosity low shear, plasma viscosity, and fibrinogen level (P > 0.05). However, there exhibited no remarkable difference in plasma viscosity and fibrinogen level at 1 day and 7 days after operation (P > 0.05). Seven days after operation, the whole blood viscosity, plasma viscosity, and fibrinogen in the study group were lower (P < 0.05). The probability of postoperative complications was compared. In the study group, there were 2 cases of limb swelling and pain, 1 case of joint stiffness, and no swelling and pain complicated with deep venous thrombosis, and the total incidence was 6.00%. In the control group, there were 5 cases of limb swelling and pain, 3 cases of joint stiffness, and 3 cases of swelling and pain complicated with deep venous thrombosis, with a total incidence of 22.00%. The incidence of adverse reactions in the study group was lower (χ 2 = 5.317 P < 0.05).

Conclusion

Early electroacupuncture combined with ERAS is of positive significance to the patients after TKA, which can reduce the pain, enhance the function of the knee joint, and promote the ROM of the knee joint, and can effectively shorten the first time out of bed and postoperative rehabilitation time and reduce whole blood viscosity low shear, plasma viscosity, and fibrinogen level, but the overall rehabilitation cost is high, and clinical application should be combined with the actual situation of patients.

Hip and Knee Arthroplasty

Variation in care is associated with variation in outcomes after total joint arthroplasty (TJA). Accordingly, much research into enhanced recovery efficacy for TJA has been devoted to linking standardization with better outcomes. This article focuses on recent advances suggesting that variation within a set of core protocol elements may be less important than providing the core elements within enhanced recovery pathways for TJA. Provided the core elements are associated with benefits for patients and health care system outcomes, variation in the details of their provision may contribute to a pathway's success. This article provides an updated review of the literature.

Comparison of iPACK and periarticular block with adductor block alone after total knee arthroplasty: a randomized clinical trial

PURPOSE

The infiltration between the popliteal artery and the capsule of the posterior knee (iPACK) has been described to provide analgesia without loss of muscle strength and is effective in functional recovery. This study compared iPACK + ACB (adductor canal block) with PAI (periarticular infiltration) + ACB and ACB alone in terms of postoperative analgesia and functional improvement.

METHODS

This double-blinded randomized controlled trial included 105 patients undergoing unilateral total knee arthroplasty. Patients received ACB, iPACK + ACB, and PAI + ACB along with spinal anesthesia. The primary outcome was the area under the curve (AUC) numeric rating scale (NRS) at 48 h. Secondary outcomes were cumulative postoperative analgesic consumption within 48 h, timed up-and-go test, range of motion, length of hospital stay, patient satisfaction, and adverse events.

RESULTS

The 48-h AUC movement NRS score in the iPACK + ACB group was significantly lower than in the PAI + ACB and ACB groups (p < 0.05). At the postoperative 48th h, the opioid consumption of the iPACK + ACB group was lower than those of the ACB and PAI + ACB groups (p < 0.001). The patients in the iPACK + ACB group had significantly shorter discharge and mobilization days than the ACB and PAI + ACB groups (p < 0.001).

CONCLUSIONS

The adding of an iPACK block to the ACB improves postoperative analgesia and reduces opioid consumption. In addition, this approach improves functional performance and reduces hospital stay.

Adductor Canal Block Combined With IPACK Block for Postoperative Analgesia and Function Recovery Following Total Knee Arthroplasty: A Prospective, Double-Blind, Randomized Controlled Study

BACKGROUND

This study aimed to explore the analgesic effect among adductor canal block (ACB) combined with infiltration between the popliteal artery and the capsule of the posterior knee (IPACK) block, ACB, and IPACK block following total knee arthroplasty (TKA).

METHODS

One hundred twenty patients were randomly allocated into 3 groups including group A (ACB + IPACK block), group B (ACB), and group C (IPACK block). The primary outcome was postoperative pain score. The secondary outcome was opioid consumption. Other outcomes included functional evaluation and postoperative complications.

RESULTS

Group A showed the lowest pain scores within 8 hours at rest and with knee maximum flexion (P < .001). From 12 to 24 hours, group C showed the highest pain scores, while no significant difference was found between group A and group B. No significant difference was found among the 3 groups 24 hours postoperatively. Group C showed the most opioid consumption within the first 24 hours and during the hospitalization, while no significant difference was found between group A and group B. No significant difference was found among the 3 groups including function evaluation and postoperative complications.

CONCLUSION

ACB + IPACK block can improve early analgesia when compared with ACB. However, the small statistical benefit to the addition of IPACK block to ACB may be unlikely to be clinically significant. Further studies may focus on patient selection and how to prolong the effect of IPACK block.

Potential New Treatments for Knee OA: A Prospective Review of Registered Trials

We aimed to evaluate potential new treatments for knee osteoarthritis (OA). The National Institute of Health ClinicalTrials.gov database was searched for “Osteoarthritis, Knee”. We found 565 ongoing interventional studies with a total planned enrollment of 111,276 subjects. Ongoing studies for knee OA represent a very small fraction of the registered clinical trials, but they are over a quarter of all knee trials and over two thirds of all OA studies. The most researched topic was arthroplasty, with aspects such as implant design changes, cementless fixation, robotic guidance, pain management, and fast track recovery. Intraarticular injections focused on cell therapies with mesenchymal stem cells sourced from adipose tissue, bone marrow, or umbilical cord. We could see the introduction of the first disease modifying drugs with an impact on knee OA, as well as new procedures such as geniculate artery embolization and geniculate nerve ablation.

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.

Comparison of sensory posterior articular nerves of the knee (SPANK) block versus infiltration between the popliteal artery and the capsule of the knee (IPACK) block when added to adductor canal block for pain control and knee rehabilitation after total knee arthroplasty---A prospective randomised trial

Background and Aims:

Adductor canal block (ACB), though an effective procedure for postoperative analgesia in total knee arthroplasty (TKA), does not provide analgesia to the posterior articular aspect of the knee joint. Infiltration between the popliteal artery and the capsule of the knee (IPACK block) and sensory posterior articular nerves of the knee (SPANK block) are two single injection techniques that have been shown to provide effective analgesia in posterior knee pain. This study aims to compare the effect of IPACK block and SPANK block when combined with ACB for analgesia and postoperative rehabilitation in TKA.

Methods:

A total of 82 patients were randomised into two groups: (1) ACB combined with IPACK, (2) ACB combined with SPANK block. The primary outcome was the pain scores from 6 h to 48 h after surgery and the duration of postoperative analgesia. The secondary outcome measures were 24 h opioid consumption, ambulation parameters like mobilisation ability, quadriceps muscle strength and patient satisfaction score at discharge.

Results:

Numerical rating scale (NRS) scores at rest and on movement, duration of analgesia, total opioid consumption, and patient satisfaction were significantly better (P < 0.05%) in the IPACK group than in the SPANK block. There were no significant differences in the knee rehabilitation parameters between the blocks.

Conclusion:

ACB with IPACK block offers better analgesia, less opioid consumption and better patient satisfaction with comparable knee rehabilitation parameters in the immediate postoperative period after TKA compared to ACB with SPANK block.