Comparative efficacy of intrathecal morphine and adductor canal block in the knee arthroplasty population: a retrospective multi-centre cohort study

BACKGROUND

Finding the balance of good postoperative analgesia while facilitiating mobility is important for a safe and satisfactory patient experience during Total Knee Arthroplasty (TKA). This study aimed to compare the efficacy of intrathecal morphine, adductor canal block, and their combination in optimizing pain management and postoperative recovery in TKA patients. This retrospective analysis of prospectively collected data evaluated postoperative pain scores, time to mobilisation, and length of hospital stay.

METHODS

1006 consecutive patients undergoing elective TKA across two large tertiary centres were included over six years. They were divided into one of four groups according to the type of analgesia received: Group N patients received no neuraxial morphine or regional block. Group B patients received adductor canal block (ACB) only. Group M patients received intrathecal morphine (ITM) but no regional block. Group BM patients received both ACB and ITM.

RESULTS

Patients who received an ACB had faster postoperative mobilization compared to those without (p < 0.001). Patients in Group BM had the lowest pain scores at rest (Visual Analogue Scale (VAS) 2.9) and with movement (VAS 5.3), while Group B patients experienced the highest pain scores at rest (VAS 3.7) and on movement (VAS 6.5) (p = 0.005). Patients who received ITM had the lowest opioid requirements (p < 0.001). There was no significant differences between groups in requirement for rescue pain management strategies (p = 0.06).

CONCLUSIONS

The combination of ITM and ACB in patients undergoing TKA provides improved postoperative analgesia with lower postoperative opioid requirement and earlier mobilization compared with ACB or ITM alone.

Predictors of subacute postoperative pain after total knee arthroplasty: A secondary analysis of two randomized trials

BACKGROUND

Methods for identifying high-pain responders undergoing total knee arthroplasty remain important to improve individualized pain management. This study aimed at evaluating pre- and perioperative predictors of pain on Days 2-7 after total knee arthroplasty.

METHODS

This is a secondary analysis of data from 227 patients participating in two randomized trials. Pain outcomes were mean pain during walking on Days 2-7 and on Days 2, 4 and 7. Multivariable linear and logistic regressions were carried out in two steps. First, only preoperative available variables including demographics, comorbidities, pain catastrophizing scale and preoperative pain were evaluated while controlling for trial intervention and recruitment site. In the second step, perioperative variables and pain during walking 24 h postoperatively were added.

RESULTS

The model with only preoperative predictors for mean pain Days 2-7 showed preoperative pain (R-squared 0.097) as the only predictor. In the second model, adding postoperative available variables, only pain 24 h postoperatively (R-squared 0.248) was significant, with a significant main effect of recruitment site. Results for the separate day analysis similarly showed preoperative pain and pain during walking 24 h postoperatively as predictors. The overall best sensitivity (60%) and specificity (74%) for predicting a high-subacute postoperative pain response on Days 2-7 was with cut-off values of VAS 45.5 (out of 100) for pain during walking 24 h postoperatively.

CONCLUSIONS

Postoperative pain during walking at 24 h is predictive of subacute postoperative pain on Days 2-7 after total knee arthroplasty, while preoperative pain was only a weak predictor.

SIGNIFICANCE STATEMENT

This study investigated factors associated with pain after total knee arthroplasty beyond the immediate postoperative period. The analysis revealed significant associations between preoperative pain levels and, particularly, pain 24 h postoperatively, with subsequent subacute pain the following week. These findings can assist in identifying patients who would benefit from enhanced, individualized analgesic interventions to facilitate postoperative recovery.

Comparative evaluation of functional outcome and pain relief after pulsed radiofrequency of the saphenous nerve within and distal to the adductor canal in medial compartment knee osteoarthritis: A randomized double-blind trial

Background and Aims

Pulsed radiofrequency (PRF) of the saphenous nerve (SN) has shown effective pain relief in knee pain because of knee osteoarthritis (KOA). The adductor canal (AC) contains other sensory nerves innervating the medial part of the knee joint apart from SN. We compared the PRF of SN within and outside the AC for their quality and duration of pain relief in knee osteoarthritis of the medial compartment (KOA-MC).

Material and Methods

We conducted a randomized prospective study in 60 patients with anteromedial knee pain because of KOA-MC. Patients in group A received PRF-SN, and those in group B received PRF-AC. The primary objectives were comparison of pain by Visual Analog Scale (VAS) scores and changes in quality of daily living by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and OXFORD knee scores. The secondary objectives were comparison of analgesic requirements using Medicine Quantification Scale (MQS) scores and block-related complications. Intra-group comparison was performed by analysis of variance. Inter-group normally distributed data were assessed by Student's t-test, non-normally distributed and ordinal data were assessed by Mann-Whitney U-test, and categorical data were assessed by Chi-square test. A P value of <0.05 was considered significant.

Results

VAS scores were significantly lower in Gr-B at 12 weeks. The WOMAC scores and OXFORD scores at 4, 8, 12, and 24 weeks were significantly lower in Gr-B compared to Gr-A.

Conclusion

The PRF-AC provides better pain relief and functional outcome than PRF-SN; however, duration of pain relief was not significantly different.

The Twenty-Five Most Cited Articles About Adductor Canal Block: A Bibliometric Analysis from 1980 to 2022

Introduction

Loco-regional anesthesia role is increasingly important in surgery, especially in postoperative pain control. Using ultrasound-guided techniques has made the loco-regional approach increasingly safe and manageable, guaranteeing excellent analgesic results and patient compliance. This bibliometric research aimed to identify the most influential papers on the adductor canal blocks and outline their characteristics.

Methods

All articles published from 1980 to 2022 were included in the Web of Science, PubMed, and Scopus databases and found using the keywords "Adductor canal block" or "Saphenous nerve block" or "Peripheral nerve block" or "Hunter canal block" or "Subsartorial canal block" or "ACB" or "Knee" or "TKR" or "TKA" or "Analgesia" or "Arthroplasty" or "Replacement" in the title section had bibliometric analysis performed. The first 25 papers were selected and analyzed by the number of citations. The correlation between numerical variables was evaluated using the Pearson Correlation coefficient.

Results

Literature screening found 252 publications. One hundred ten were only about the adductor canal block. Of these, 25 articles were selected for our bibliometric study, published in 8 different journals and with a total number of citations equal to 1.457. "Regional Anesthesia and pain medicine" journal - with 9 articles - was the one that produced the most. There was a significant strong correlation between the n. of citations and the citation rate (R = 0.84, p < 0.001).

Conclusion

The purpose of this study is to be a guide on regional anesthesia and, particularly, on adductor canal block, making the most effective as well as the most cited articles available to anesthesiologists or other researchers interested in this topic.

Motor-Sparing Effect of Adductor Canal Block for Knee Analgesia: An Updated Review and a Subgroup Analysis of Randomized Controlled Trials Based on a Corrected Classification System

OBJECTIVE

Discrepancies in the definition of adductor canal block (ACB) lead to inconsistent results. To investigate the actual analgesic and motor-sparing effects of ACB by anatomically defining femoral triangle block (FTB), proximal ACB (p-ACB), and distal ACB (d-ACB), we re-classified the previously claimed ACB approaches according to the ultrasound findings or descriptions in the corresponding published articles. A meta-analysis with subsequent subgroup analyses based on these corrected results was performed to examine the true impact of ACB on its analgesic effect and motor function (quadriceps muscle strength or mobilization ability). An optimal ACB technique was also suggested based on an updated review of evidence and ultrasound anatomy.

MATERIALS AND METHODS

We systematically searched studies describing the use of ACB for knee surgery. Cochrane Library, PubMed, Web of Science, and Embase were searched with the exclusion of non-English articles from inception to 28 February 2022. The motor-sparing and analgesic aspects in true ACB were evaluated using meta-analyses with subsequent subgroup analyses according to the corrected classification system.

RESULTS

The meta-analysis includes 19 randomized controlled trials. Compared with the femoral nerve block group, the quadriceps muscle strength (standardized mean difference (SMD) = 0.33, 95%-CI [0.01; 0.65]) and mobilization ability (SMD = -22.44, 95%-CI [-35.37; -9.51]) are more preserved in the mixed ACB group at 24 h after knee surgery. Compared with the true ACB group, the FTB group (SMD = 5.59, 95%-CI [3.44; 8.46]) has a significantly decreased mobilization ability at 24 h after knee surgery.

CONCLUSION

By using the corrected classification system, we proved the motor-sparing effect of true ACB compared to FTB. According to the updated ultrasound anatomy, we suggested proximal ACB to be the analgesic technique of choice for knee surgery. Although a single-shot ACB is limited in duration, it remains the candidate of the analgesic standard for knee surgery on postoperative day 1 or 2 because it induces analgesia with less motor involvement in the era of multimodal analgesia. Furthermore, data from the corrected classification system may provide the basis for future research.

Effects of esketamine on postoperative rebound pain in patients undergoing unilateral total knee arthroplasty: a single-center, randomized, double-blind, placebo-controlled trial protocol

Introduction

Rebound pain, transient and acute postoperative pain after the disappearance of regional block anesthesia, has been a concern in recent years. Insufficient preemptive analgesia and hyperalgesia induced by regional block are the main mechanisms. At present, the evidence for the treatment of rebound pain is limited. The esketamine, as an antagonist of the N-methyl-D-aspartate receptor, has been proven to prevent hyperalgesia. Therefore, this trial aims to evaluate the impact of esketamine on postoperative rebound pain in patients undergoing total knee arthroplasty.

Methods/design

This study is a single-center, prospective, double-blind, randomized, placebo-controlled trial. Participants who plan to undergo total knee arthroplasty will be randomly assigned to the esketamine group (N = 178) and placebo group (N = 178) in a ratio of 1:1. This trial aims to evaluate the impact of esketamine on postoperative rebound pain in patients undergoing total knee arthroplasty. The primary outcome of this trial is the incidence of rebound pain within 12 h after the operation in the esketamine group and the placebo group. The secondary outcome will be to compare (1) the incidence of rebound pain 24 h after the operation; (2) the time to enter the pain cycle for the first time within 24 h after the procedure; (3) the first time of rebound pain occurred within 24 h after surgery; (4) the modified rebound pain score; (5) NRS score under rest and exercise at different time points; (6) the cumulative opioid consumption at different time points; (7) patient's prognosis and knee joint function evaluation; (8) blood glucose and cortisol concentration; (9) patient's satisfaction score; (10) adverse reactions and adverse events.

Discussion

The effect of ketamine on preventing postoperative rebound pain is contradictory and uncertain. The affinity of esketamine to the N-methyl-D-aspartate receptor is about four times higher than levo-ketamine, the analgesic effect is 3 times higher than levo-ketamine, and there are fewer adverse mental reactions. To our knowledge, there is no randomized controlled trial to verify the impact of esketamine on postoperative rebound pain in patients undergoing total knee arthroplasty. Therefore, this trial is expected to fill an important gap in relevant fields and provide novel evidence for individualized pain management.

Clinical Trial Registration

http://www.chictr.org.cn, identifier ChiCTR2300069044.

Efficacy of single-shot adductor canal block before Versus after primary total knee arthroplasty - Does timing make a difference? A randomized controlled trial

BACKGROUND

Total knee arthroplasty (TKA) is associated with severe postoperative pain. Multimodal analgesia, including peripheral nerve block, is recommended for post-operative pain relief. Administration of some pain medications prior to surgery has shown to be more effective than after the operation. This is a prospective, randomized controlled trial designed to compare the analgesic efficacy of the adductor canal block (ACB) performed immediately before or immediately after primary total knee arthroplasty (TKA). We hypothesized that ACB before the surgery will reduce postoperative pain and improve knee function.

METHODS

A total of 50 patients were enrolled and randomized into 2 groups, with 26 patients receiving a preoperative ACB and 24 receiving a postoperative ACB.

RESULTS

Treatment groups were similar in terms of gender (p = .83), age (p = 0.61) weight (p = .39) and ASA score. Average visual analogue scale (VAS) on arrival to the post-anesthesia care unit (PACU) were 4.9 ± 3.2 in the preoperative ACB versus 3.4 ± 2.8 for the postoperative ACB (p = .075). VAS scores at different time points as well as the mean, minimal and maximal reported VAS scores were not significantly different between the two groups. The cumulative quantities of Fentanyl administered by the anesthesia team was comparable between the groups. Similarly, the dosage of Morphine, Tramadol, Acetaminophen and Dipyrone showed only small variations. The Quality of Recovery Score, Knee Society Scores and knee range of motion did not differ between the groups.

CONCLUSIONS

Our findings demonstrate no significant differences in patient total narcotics consumption, pain scores and functional scores, between preoperative and postoperative ACB in patients undergoing TKA.

TRIAL REGISTRATION

The trial was registered at www.clinicaltrials.gov and was assigned the registration number NCT02908711.

LEVEL OF EVIDENCE

level I randomized controlled trial.

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.

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.

A Comparative Study of Ultrasound-Guided Continuous Adductor Canal Block With Ultrasound-Guided Continuous Femoral Nerve Block in Unilateral Total Knee Arthroplasty for Limb Mobilization and Analgesic Efficacy

Background

Total knee joint replacement surgery is associated with severe postoperative pain and is amenable to regional anesthesia techniques for pain control. Femoral nerve block (FNB) provides effective analgesia after total knee arthroplasty (TKA) but has been associated with delayed ambulation due to quadriceps muscle weakness. Adductor canal block (ACB) may be a promising alternative, with less effect on the quadriceps muscle and comparable analgesic efficacy. We evaluated the effectiveness, safety, and patient satisfaction of continuous ACB augmented with infiltration between the popliteal artery and capsule of the knee (iPACK) block and compared them with those of continuous FNB amplified with iPACK block in preventing postoperative pain among patients undergoing unilateral total knee replacement (TKR) surgeries.

Methodology

According to a computer-generated sequence from September 2019 to June 2020, 50 American Society of Anesthesiologists grades I-III patients aged between 35 and 75 years who underwent unilateral TKR surgery were randomized into two equal groups, namely, ACB and FNB. The Timed Up and Go (TUG) and 10-minute walk tests were used to detect early ambulation (impact on quadriceps muscle). The secondary goal was to evaluate and compare opioid consumption and analgesic efficacy between the groups measured using a numeric rating scale (NRS). The demographic characteristics, technical difficulty, efficiency, safety, and comfort were compared between the two groups.

Results

During the postoperative period, patients in the ACB group could perform all TUG tests significantly faster than those in the FNB group. The mean get-up time in the ACB group was 39.08 ± 5.53 seconds, whereas that in the FNB group was 44.92 ± 7.10 seconds (p < 0.01). The 3-m walk time was 123.16 ± 15.90 seconds in the ACB group and 134.68 ± 13.13 seconds in the FNB group (p < 0.01). The 10-m walk time was 221.24 ± 18.82 seconds in the ACB group and 245.24 ± 21.68 seconds in the FNB group (p < 0.001). No significant difference was observed in NRS scores between the groups after the first 24 hours. The number of opioids available for consumption in both groups was equivalent.

Conclusions

ACB when augmented with an iPACK block is a good alternative to FNB for unilateral TKR surgeries. ACB may promote early ambulation without a reduction in analgesia when compared with FNB.

Evaluation of ultrasound-guided adductor canal block with two different concentration of bupivacaine in arthroscopic knee surgery: A feasibility study

STUDY OBJECTIVE

The application of regional anaesthesia techniques as a component of multimodal analgesia in knee arthroscopic surgeries increases the quality of postoperative analgesia. Adductor canal block (ACB) is an effective "motor sparing" analgesia technique used in knee surgeries. This study aimed to evaluate the efficacy of ACB using two different concentrations of local anaesthetic in terms of analgesic requirements and pain density in patients undergoing knee arthroscopy.

DESIGN

Prospective, randomised, controlled.

SETTING

Tertiary hospital.

PATIENTS

A total of 60 patients (ASA I-II) were evaluated in three groups, with 20 patients in each group.

INTERVENTIONS

Standardised postoperative analgesia was performed in all groups. In addition, ultrasound-guided ACB (same volume/two different concentrations of bupivacaine: 0.25% vs 0.16%) was applied to the experimental groups.

MEASUREMENTS

Tramadol consumption, rescue analgesic requirement and Numeric Rating Scores (NRS).

MAIN RESULTS

Tramadol requirement in the first 24 hours was significantly higher in the control group (209.5 ± 23.27 mg) (P < .001), and there was no difference between the experimental groups (63 ± 42.06 mg vs 80.5 ± 36.63 mg). Although the mean NRS scores in the first three hours were higher in the control group when compared with both block groups, it was similar in all groups in the following measurements.

CONCLUSION

In arthroscopic knee surgery, ACB interventions with 0.25% and 0.16% concentrations of bupivacaine were similar in terms of postoperative analgesic efficacy, and they increased the quality of multimodal analgesics when compared with the control group.

Adductor canal block performed 20 hours after total knee arthroplasty to improve postoperative analgesia and functional recovery: a double-blind randomized controlled clinical trial

BACKGROUND

The goal of postoperative pain protocols in total knee arthroplasty (TKA) is to get pain free patients throughout severe pain period without impairing walking ability. The aim of the study was to investigate if an adductor canal block performed 20 hours after TKA, in patients treated with systemic analgesia and intraoperative local infiltration anaesthesia (LIA), improves postoperative pain and functional outcomes.

METHODS

A prospective randomized, double blinded controlled study was conducted. One hundred eighty-three patients undergoing primary TKA were randomized to receive either a sham block or an adductor canal block with 20 ml of ropivacaine 0.5%. The primary outcome was resting and dynamic pain scores using the numerical pain rating scale (NPRS). Secondary outcomes included opioid rescue requirements, quadriceps and adductor muscle strength, patient ability for ambulation and complications.

RESULTS

Two hours after the block, in adductor canal block group NPRS was significantly lower at rest (1[0-2] vs. 3[2-5], P<0.001) and with mobilization (5[3-6] vs. 6[5-8], P<0.001), and quadriceps strength was significantly higher (3.7[2.7-6] vs. 3(1.7-4.9), P=0.023). The differences were not maintained beyond 24 hours post-block. In the first 24 hours the percentage of patients with tramadol requirements was lower in the adductor canal block group (36[38.3] vs 52[58,4], P =0.006). Other secondary outcomes were similar between groups. There were no patient falls.

CONCLUSIONS

An adductor canal block done 20 hours after total knee arthroplasty reduces pain and opioid requirements without increasing the risk of falls. An optimal pain control, especially at movement was not achieved.

Ultrasound-guided genicular nerve blocks following total knee arthroplasty: a randomized, double-blind, placebo-controlled trial

INTRODUCTION

Local anesthetic blockade of the genicular nerves, known targets of radiofrequency ablative techniques for knee pain, has not previously been studied in a randomized controlled trial evaluating acute pain after knee arthroplasty. We hypothesized that genicular nerve blockade added to an existing block regimen in total knee arthroplasty would result in a reduction in 24 hours opioid consumption.

METHODS

Patients (American Society of Anesthesiologists 1-3, aged 18-85 years) undergoing primary total knee arthroplasty were randomized to receive single-injection nerve blocks of the superolateral, superomedial, and inferomedial genicular nerves with injectate (15 mL 0.25% bupivacaine and 2 mg dexamethasone or 15 mL saline placebo). All subjects received a standard oral analgesic regimen, spinal anesthetic with 12.5 mg isobaric bupivacaine, infiltration between the popliteal artery and capsule of the knee with 0.2% ropivacaine, and postoperative adductor canal perineural infusion with 0.2% ropivacaine. The primary outcome was 24 hours opioid consumption (measured in morphine milliequivalents).

RESULTS

Forty (40) subjects were enrolled. Opioid consumption at 24 hours was significantly lower in the BLOCK group compared with the SHAM group (23±20 vs 58±35, p<0.001), and this difference remained significant at 48 hours (50±40 vs 98±56, p=0.004). Pain scores were reduced in the BLOCK group at time 6 hours (2.6±1.9 vs 4.3±2.2, p=0.012), but were otherwise similar at remaining time points. Patient satisfaction at 24 hours and 20 m walk test times were similar between groups.

DISCUSSION

Genicular nerve blockade was associated with a reduction in opioid consumption at 24 hours in primary total knee arthroplasty patients.

TRIAL REGISTRATION NUMBER

NCT03706313.

Assessing outcome in postoperative pain trials: are we missing the point? A systematic review of pain-related outcome domains reported in studies early after total knee arthroplasty

ABSTRACT

The management of acute postoperative pain remains suboptimal. Systematic reviews and Cochrane analysis can assist with collating evidence about treatment efficacy, but the results are limited in part by heterogeneity of endpoints in clinical trials. In addition, the chosen endpoints may not be entirely clinically relevant. To investigate the endpoints assessed in perioperative pain trials, we performed a systematic literature review on outcome domains assessing effectiveness of acute pain interventions in trials after total knee arthroplasty. We followed the Cochrane recommendations for systematic reviews, searching PubMed, Cochrane, and Embase, resulting in the screening of 1590 potentially eligible studies. After final inclusion of 295 studies, we identified 11 outcome domains and 45 subdomains/descriptors with the domain "pain"/"pain intensity" most commonly assessed (98.3%), followed by "analgesic consumption" (88.8%) and "side effects" (75.3%). By contrast, "physical function" (53.5%), "satisfaction" (28.8%), and "psychological function" (11.9%) were given much less consideration. The combinations of outcome domains were inhomogeneous throughout the studies, regardless of the type of pain management investigated. In conclusion, we found that there was high variability in outcome domains and inhomogeneous combinations, as well as inconsistent subdomain descriptions and utilization in trials comparing for effectiveness of pain interventions after total knee arthroplasty. This points towards the need for harmonizing outcome domains, eg, by consenting on a core outcome set of domains which are relevant for both stakeholders and patients. Such a core outcome set should include at least 3 domains from 3 different health core areas such as pain intensity, physical function, and one psychological domain.

Retrospective Analysis of Pain Relief in Total Knee Replacement Surgeries

Background and Aims

The aim of the study is to measure the postoperative adequacy of pain relief and functional recovery after unilateral primary total knee arthroplasty or total knee replacement (TKR) with a multimodal approach.

Settings and Design

This was a retrospective observational study done in a tertiary care center.

Materials and Methods

Eighty patients aged 18-65 years (yrs) with ASA Physical Status Classes I, II, and III operated for unilateral primary TKR surgery under suitable Anaesthesia and was administered ultrasound-guided adductor canal block + periarticular infiltration (PI) from January 2018 to January 2019 were included. Thereafter, the patients visual analog scale (VAS) scores at rest, 45° knee flexion, and mobilization as well as additional analgesia given were noted after going through the records at following time points: 12 hourly for 24 h and thereafter on postoperative day 1 (POD1) and POD2. Level of block, adverse events, and functional recovery (time up and go [TUG] test, 10 s walk test) on POD1 and POD2 were also noted.

Statistical Analysis and Results

The statistical software namely SPSS 18.0 were used for the analysis of the data. The mean VAS score at 12 h was 4.33 ± 1.3 which worsened at 24 h with steady improvement over the next 2 days. Similarly, the case with a mean VAS score at 45° flexion and on mobilization showed a similar trend. At 12 h postadductor block, besides intravenous (i.v.) paracetamol, 32.6% of patients were given tramadol 50 mg i.v. whereas one patient was given a buprenorphine patch in addition to tramadol. The number of patients requiring additional tramadol and buprenorphine patch steadily increased over the next 2 days. The average time taken for the TUG test at 24 h was 30.98 ± 4.77 s, and the average time taken for the 10 s walk test at 24 h was 6.16 ± 1.10 steps with improvement in performance over the next 2 days.

Conclusion

In our study, our multimodal analgesia model did not provide satisfactory analgesia though mobilization was not hampered.

Comparison of adductor canal block with femoral nerve block for post-operative pain relief after bilateral total knee arthroplasty: A non-randomised controlled trial

Background and Aims

Pain perception and pain threshold vary from one individual to another and also differ in the right and left limbs leading to an inter-cerebral pain variability bias and inter-patient pain variability bias. To date, data comparing adductor canal block (ACB) with femoral nerve block (FNB) in the same patient who underwent bilateral total knee arthroplasty (TKA) remain limited.

Methods

We performed a prospective, non-randomised, controlled study. Patients scheduled for bilateral TKA with central neuraxial anaesthesia received every 12-hourly intermittent boluses of 15 mL of ropivacaine 0.5% in two different peripheral nerve blocks (ACB and FNB) in either of the lower limbs postoperatively. The primary outcome was to assess postoperative VAS score, and the secondary outcomes were muscle strength of the quadriceps muscle and degree of flexion at the knee joint.

Results

Among the 80 patients assessed for eligibility, 72 patients were enroled, and 69 were included in the final analysis. VAS scores after the two blocks during rest at 30 minutes, 6 hours, 12 hours and 48 hours post-operatively had no significant difference. VAS scores during rest at 24 hours and on doing exercise at 24 hours and 48 hours showed a significant difference. Quadriceps muscle strength and degree of flexion of knee at 24 hours and 48 hours post-operatively did show a significant difference in favour of the ACB over FNB.

Conclusion

ACB provides equivalent analgesia in comparison with FNB at rest and during passive exercise up to 48 hours post-operatively. ACB significantly preserved motor power of quadriceps muscles when compared with FNB with no added complications.

Continuous adductor canal block provides better performance after total knee arthroplasty compared with the single-shot adductor canal block?: An updated meta-analysis of randomized controlled trials

BACKGROUND

Adductor canal block (ACB) has emerged as an attractive alternative for femoral nerve blocks (FNB) as the peripheral nerve block of choice for total knee arthroplasty (TKA), preserving quadriceps motor function while providing analgesia comparable to FNB. However, its optimal application for TKA remains controversial. The objective of this meta-analysis was to compare continuous-injection ACB (CACB) vs single-injection ACB (SACB) for postoperative pain control in patients undergoing TKA.

METHODS

This study attempts to identify the available and relevant randomized controlled trials (RCTs) regarding the analgesic effects of CACB compared to SACB in patients undergoing TKA according to electronic databases, including PubMed, Medline, Web of Science, EMbase, and the Cochrane Library, up to September 2019. Primary outcomes in this regard included the use of a visual analogue scale (VAS) pain score with rest or activity, while secondary outcomes were cumulative opioid consumption, length of hospital stay (LOS), complications of vomiting and nausea, and rescue analgesia. The corresponding data were analyzed using RevMan v5.3.

ETHICAL REVIEW

Because all of the data used in this systematic review and meta-analysis has been published, the ethical approval was not necessary RESULTS:: This research included 9 studies comprised of 739 patients. The analyzed outcomes demonstrated that patients who received CACB had a better at rest-VAS scores at 4 hours (P = .007), 8 hors (P < .0001), 12 hours (P < .0001), 24 hours (P = .02), mobilization-VAS score at 48 hours (P < .0001), and rescue analgesia (P = .03) than those who underwent SACB. Nevertheless, no significant differences were present between the 2 strategies in terms of pain VAS scores 48 hours at rest (P = .23) and 24 hours at mobilization (P = .10), complications of vomiting and nausea (P = .42), and length of hospital stay (P = .09).

CONCLUSION

This meta-analysis indicated that CACB is superior to SACB in regard to analgesic effect following TKA. However, due to the variation of the included studies, no firm conclusions can be drawn. Further investigations into RCT are required for verification.

Motor-sparing nerve blocks for total knee replacement: A scoping review

STUDY OBJECTIVE

This scoping review investigates the optimal combination of motor-sparing analgesic interventions for patients undergoing total knee replacement (TKR).

DESIGN

Scoping review.

INTERVENTION

MEDLINE, EMBASE and CINAHL databases were searched (inception-last week of May 2020). Only trials including motor-sparing interventions were included. Randomized controlled trials lacking prospective registration and blinded assessment were excluded.

MAIN RESULTS

The cumulative evidence suggests that femoral triangle blocks outperform placebo and periarticular infiltration. When combined with the latter, femoral triangle blocks are associated with improved pain control, higher patient satisfaction and decreased opioid consumption. Continuous femoral triangle blocks provide superior postoperative analgesia compared with their single-injection counterparts. However, these benefits seem less pronounced when perineural adjuvants are used. Combined femoral triangle-obturator blocks result in improved analgesia and swifter discharge compared with femoral triangle blocks alone.

CONCLUSIONS

The optimal analgesic strategy for TKR may include a combination of different analgesic modalities (periarticular infiltration, femoral triangle blocks, obturator nerve block). Future trials are required to investigate the incremental benefits provided by local anesthetic infiltration between the popliteal artery and the capsule of the knee (IPACK), popliteal plexus block and genicular nerve block.

Analgesic effectiveness of Local Infiltrative Analgesia alone versus combined single dose adductor canal block with Local Infiltrative Analgesia: A single centre case control study

BACKGROUND

Both adductor canal block (ACB) and of Local Infiltrative Analgesia (LIA) have been shown to reduce pain after total knee arthroplasty (TKA). The efficacy of combining ACB and LIA remains controversial. The objective of this study is to analyse the effect of LIA + single dose ACB compared to LIA alone on early post-operative pain and mobilization in TKA.

METHODS

This Cohort Prospective study analyses the Visual Analogue Score (VAS) pain scores and rehabilitation milestones at 24 h between LIA alone and LIA + single dose ACB in unilateral TKA operated by a single surgeon between August 2014 and February 2019.

RESULTS

VAS at rest and on movement were significantly better in the combined LIA + ACB group (n = 151) compared to LIA (n = 120) alone at 24 h. All patients were able to achieve the desired milestones of sitting, standing by the bedside and walking with the help of a walker within 24 h of the surgery.

CONCLUSION

Though the VAS scores were statistically significant, the actual scores at rest and on movement in both groups were significantly better than preoperative scores with excellent pain relief. All patients in both groups were able to ambulate within 24 h. LIA alone significantly improved the pain scores and enabled early mobilization. Addition of single dose ACB to LIA did not significantly alter the milestones.

The feasibility of direct adductor canal block (DACB) as a part of periarticular injection in total knee arthroplasty

BACKGROUND

Adductor canal block (ACB) is one of the preferred methods of analgesia in total knee arthroplasty (TKA). However, conventionally its use is time-consuming, requires ultrasound guidance, a trained anaesthesia team and adherence to strict asepsis by members of the allied teams. This study was done to assess the feasibility and safety of direct adductor canal block (DACB) as a part of surgeon-administered periarticular infiltration.

MATERIALS AND METHODS

Thirty computed tomography (CT) angiography films of the patients were retrospectively reviewed. The trajectory of the needle placement for a DACB in relation to the target region of the adductor block was determined. Fourteen knees in seven cadavers, were dissected through a medial parapatellar approach to perform TKA. After administering the DACB using the technique based on CT data, dissection was carried out to ascertain the correct placement of the dye by visualising the stained areas.

RESULTS

The angle of approach in the coronal plane from the entry point to the medial high point and to the adductor hiatus was 10.2° (8-14°) and 6° (3.8-11°), respectively. The angle of approach in the sagittal plane from the entry point to the medial high point and to the adductor hiatus was 7° (5-10.5°) and 29° (19-43°), respectively. In all the 14 cadaveric knees, we confirmed the correct placement of the methylene blue dye as demonstrated by the staining of the adductor canal.

CONCLUSION

The study demonstrates the feasibility of the DACB. This surgeon-driven technique is likely to reduce the cost of the procedure, reduce operating room time and also eliminate the risks of surgical-site contamination.

Adductor canal block is similar to femoral nerve block for the quality of rehabilitation after arthroscopic partial meniscectomy

PURPOSE

Adductor canal block (ACB) provides postoperative pain relief as effectively as femoral nerve block (FNB) does, and it preserves the strength of the quadriceps femoris. However, its effect on rehabilitation after arthroscopic partial meniscectomy has not been reported. The purpose of this study was to determine the effect of pre-operative ACB and FNB on the quality of rehabilitation after arthroscopic partial meniscectomy.

METHODS

A total of 150 patients undergoing arthroscopic partial meniscectomy were randomly allocated to the FNB group (receiving 0.3% ropivacaine 30 ml at the thighroot-femoral nerve), the ACB group (receiving 0.3% ropivacaine 30 ml at mid-thigh adductor canal), or the control group. The primary outcome was the Hospital for Special Surgery (HSS) knee score on the 30th postoperative day.

RESULTS

The HSS knee score of the ACB group on the 30th day after the operation was significantly higher than those of the FNB and control groups (88.6 ± 5.3 vs. 85.3 ± 6.9 and 81.2 ± 5.9, respectively; P < 0.05). Both the ACB and FNB groups showed excellent rehabilitation, indicating similar rehabilitation quality for both treatments.

CONCLUSION

ACB is similar to FNB concerning the quality of rehabilitation and pain relief after arthroscopic partial meniscectomy, while ACB has little effect on the strength of the quadriceps femoris.

LEVEL OF EVIDENCE

I TRIAL REGISTRATAION: This trial was registered in the Chinese Clinical Trial Registry (ChiCTR-INC-16008346).

Adductor canal blocks for postoperative pain treatment in adults undergoing knee surgery

BACKGROUND

Peripheral regional anaesthesia techniques are well established for postoperative pain treatment following knee surgery. The adductor canal block (ACB) is a new technique, which can be applied as a single shot or by catheter for continuous regional analgesia.

OBJECTIVES

To compare the analgesic efficacy and adverse events of ACB versus other regional analgesic techniques or systemic analgesic treatment for adults undergoing knee surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, and Embase, five other databases, and one trial register on 19 September 2018; we checked references, searched citations, and contacted study authors to identify additional studies.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) comparing single or continuous ACB versus other regional analgesic techniques or systemic analgesic treatment. Inclusion was independent of the technique used (landmarks, peripheral nerve stimulator, or ultrasound) and the level of training of providers.

DATA COLLECTION AND ANALYSIS

We used Cochrane's standard methodological procedures. Our primary outcomes were pain intensity at rest and during movement; rate of accidental falls; and rates of opioid-related adverse events. We used GRADE to assess the quality of evidence for primary outcomes.

MAIN RESULTS

We included 25 RCTs (1688 participants) in this review (23 trials combined within meta-analyses). In 18 studies, participants underwent total knee arthroplasty (TKA), whereas seven trials investigated patients undergoing arthroscopic knee surgery. We identified 11 studies awaiting classification and 11 ongoing studies. We investigated the following comparisons. ACB versus sham treatment We included eight trials for this comparison. We found no significant differences in postoperative pain intensity at rest (2 hours: standardized mean difference (SMD) -0.56, 95% confidence interval (CI) -1.20 to 0.07, 4 trials, 208 participants, low-quality evidence; 24 hours: SMD -0.49, 95% CI -1.05 to 0.07, 6 trials, 272 participants, low-quality evidence) or during movement (2 hours: SMD -0.59, 95% CI -1.5 to 0.33; 3 trials, 160 participants, very low-quality evidence; 24 hours: SMD 0.03, 95% CI -0.26 to 0.32, 4 trials, 184 participants, low-quality evidence). Furthermore, they noted no evidence of a difference in postoperative nausea between groups (24 hours: risk ratio (RR) 1.91, 95% CI 0.48 to 7.58, 3 trials, 121 participants, low-quality evidence). One trial reported that no accidental falls occurred 24 hours postoperatively (low-quality evidence). ACB versus femoral nerve block We included 15 RCTs for this comparison. We found no evidence of a difference in postoperative pain intensity at rest (2 hours: SMD -0.74, 95% CI -1.76 to 0.28, 5 trials, 298 participants, low-quality evidence; 24 hours: SMD 0.04, 95% CI -0.09 to 0.18, 12 trials, 868 participants, high-quality evidence) or during movement (2 hours: SMD -0.47, 95% CI -1.86 to 0.93, 2 trials, 88 participants, very low-quality evidence; 24 hours: SMD 0.56, 95% CI -0.00 to 1.12, 9 trials, 576 participants, very low-quality evidence). They noted no evidence of a difference in postoperative nausea (24 hours: RR 1.22, 95% CI 0.42 to 3.54, 2 trials, 138 participants, low-quality evidence) and no evidence that the rate of accidental falls during postoperative care was significantly different between groups (24 hours: RR 0.20, 95% CI 0.04 to 1.15, 3 trials, 172 participants, low-quality evidence).

AUTHORS' CONCLUSIONS

We are currently uncertain whether patients treated with ACB suffer from lower pain intensity at rest and during movement, fewer opioid-related adverse events, and fewer accidental falls during postoperative care compared to patients receiving sham treatment. The same holds true for the comparison of ACB versus femoral nerve block focusing on postoperative pain intensity. The overall evidence level was mostly low or very low, so further research might change the conclusion. The 11 studies awaiting classification and the 11 ongoing studies, once assessed, may alter the conclusions of this review.

Effect of Adductor Canal Block on Acute Perioperative Pain and Function in Total Knee Arthroplasty

BACKGROUND

Multimodal pain management strategies are commonplace in perioperative management of total knee arthroplasty (TKA), although controversy remains regarding the role of adductor canal blocks (ACB) in this algorithm. The purpose of this study is to independently evaluate the effect of ACB on short-term postoperative outcomes including (1) length of stay (LOS), (2) postoperative narcotic utilization, and (3) function with physical therapy in the era of modern TKA.

METHODS

We retrospectively identified a cohort of consecutive patients from January 2014 to January 2018 who had undergone unilateral primary TKA using a single-shot ACB in addition to a standardized multimodal pain regimen vs those who only received a multimodal pain regimen. These 2 groups were compared using independent sample t-tests with primary end points of interest being LOS, distance ambulated with therapy, and inpatient narcotic use.

RESULTS

There were 624 patients in the ACB group, with a mean age of 64.5 years. The group without ACB consisted of 69 patients, with a mean age of 67.2 years. We observed no significant difference in narcotic utilization postoperatively (2.361 vs 2.097, P = .088). The ACB group ambulated significantly further with therapy (75.8 vs 59.9 ft, P = .008) and had a shorter LOS in both total hours and percentage of postoperative day 1 (%POD1) discharges (34.8 vs 40.6 hours, P = .01, 83% vs 66.6%, P = .01).

CONCLUSION

ACB did not decrease postoperative pain medication utilization. The modest improvement in distance ambulated with therapy on POD1 (16 ft) and LOS (16% greater POD1 discharges) may not support the cost-effectiveness of this intervention.

LEVEL OF EVIDENCE

III, Retrospective Cohort.

The effects of adding local infiltration analgesia of the knee to a multimodal pain protocol for total arthroplasty: A matched pair retrospective study

Background: We hypothesize that the addition of local infiltration analgesia (LIA) to a multimodal pain protocol will reduce the total amount of opioids consumed for acute pain control post total knee arthrolplasty (TKA).

Methods: This study was a retrospective, matched pair study including patients who had primary TKA. All patients included in the analysis had preoperative oral celecoxib and acetaminophen, had single-dose spinal anesthetic with intrathecal morphine, and had intravenous patient-controlled analgesia with an opioid agent in addition to gabapentin and celecoxib in the first 48 h. Patients whose charts were excluded from the study had revision TKA, received opioid therapy prior to the surgery, were classified as American Society of Anesthesiology (ASA) IV, and had general anesthesia. Fifty patients who underwent TKA and had LIA were matched for age, body mass index (BMI), and gender with patients who did not receive LIA. The primary outcome measures were total doses of opioids consumed post TKA.

Results: Patients receiving LIA consumed on average significantly less intravenous (IV) morphine equivalents than patients not receiving LIA, with a mean difference (±SD) of 88.9 ± 15.6 mg IV morphine equivalents. Furthermore, pain control was better in the LIA group. The incidences of nausea and vomiting, pruritis, and excessive sedation were higher in the non-LIA group compared to the LIA group. There was no difference in the hospital length of stay between both groups.

Conclusions: The addition of LIA to our multimodal pain protocol for TKA was associated with a reduction in total opioid consumption.

Relative Contributions of Adductor Canal Block and Intrathecal Morphine to Analgesia and Functional Recovery After Total Knee Arthroplasty: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

Effective postoperative analgesia may enhance early rehabilitation after orthopedic surgery. This randomized double-blind trial investigates the relative contributions of adductor canal block and low-dose intrathecal morphine (ITM) to postoperative analgesia and functional recovery after total knee arthroplasty.

METHODS

Two-hundred one patients undergoing elective unilateral total knee arthroplasty under spinal anesthesia were randomized to 3 groups. All patients received standardized intraoperative local infiltration analgesia and postoperative oral analgesics. Patients in group 1 received a "sham" adductor canal block with 30 mL of normal saline. Patients in group 2 received an adductor canal block with 30 mL of ropivacaine 0.5% with 1:400,000 epinephrine, whereas patients in group 3 received the adductor canal block with the active drug and 100 μg of ITM. The primary outcome measure was the Timed Up and Go (TUG) test on the second postoperative day. Secondary outcomes included postoperative pain scores and opioid requirements, distance walked, time to hospital discharge, and self-reported functional outcomes at 3 months.

RESULTS

All 3 groups had similar values of TUG test on postoperative day (POD) 2 (46 [36-62], 45 [33-61], and 52 [41-69]; P = 0.166) as well as other short-term and 3-month functional outcomes. Patients in group 3 showed a favorable analgesic profile as evidenced by 3 positive secondary outcomes. These positive outcomes were lower pain scores 12 hours postoperatively both at rest (4 [2-6.3], 4 [2.3-6], and 3 [1-4]; P = 0.007) and on movement (6 [4-8], 6 [3-8], and 4 [2-6]; P = 0.002), a lower incidence of "rescue" intravenous patient-controlled analgesia (42%, 34%, and 20%; P = 0.031), and the lowest cumulative opioid requirements for the first 48 hours postoperatively (86 ± 71, 68 ± 46, and 59 ± 39; P < 0.005, group 3 compared with group 1).

CONCLUSIONS

Our data suggest that there is no difference in either the primary outcome of TUG test on POD 2, other immediate functional secondary outcomes, or in global functional outcome at 3 months postoperatively across all 3 groups. Our data also suggest an improved analgesic profile in the first 48 hours postoperatively when both adductor canal block and low-dose ITM (100 μg) are added to local infiltration analgesia as evidenced by several positive secondary outcomes of lower pain scores and opioid requirements.

CLINICAL TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov, identifier NCT02411149.

The Prolonged Analgesic Efficacy of an Ultrasound-Guided Single-Shot Adductor Canal Block in Patients Undergoing Total Knee Arthroplasty

In this prospective, randomized, placebo-controlled study, the authors compared the analgesic efficacy of the single-shot adductor canal block (SS-ACB) vs the continuous adductor canal block (C-ACB) with intermittent boluses during the 72-hour postoperative period. Seventy-five patients randomly received the following: a single shot of 20 mL of 0.5% ropivacaine preoperatively followed by intermittent saline boluses at 12 hours and 24 hours postoperatively (SS-ACB group); 20 mL of 0.5% ropivacaine preoperatively and 12 hours and 24 hours postoperatively (C-ACB group); or saline preoperatively and postoperatively (control group). The primary outcome was visual analog scale pain scores with movement on postoperative day 1. The dynamic pain scores of the 2 ACB groups were equivalent and were lower than those of the control group on postoperative day 1. Compared with the control group, the 2 ACB groups were less likely to use opioids on the operative day and the first 2 postoperative days. The patients in the control group and the C-ACB group exhibited less quadriceps muscle strength than those in the SS-ACB group on postoperative day 1. The time required for an SS-ACB was markedly shorter than that required for an indwelling adductor canal catheter. Further, each adductor canal catheter cost $80. Patients who received a single block reported more satisfaction with their pain-relief treatment. Given the similar analgesic effect but better quadriceps muscle strength, easier execution, and higher patient satisfaction, the SS-ACB may be more suitable for total knee arthroplasty patients than the C-ACB. [Orthopedics. 2018; 41(5):e607-e614.].

Evaluation of analgesic efficacy of dexmedetomidine as adjuvant with ropivacaine in ultrasound-guided adductor canal block in patients following anterior cruciate ligament reconstruction surgeries

Introduction

Local anaesthetic (LA) with highly selective alpha-2 agonist dexmedetomidine has not been evaluated in adductor canal block (ACB) for arthroscopic anterior cruciate ligament (ACL) reconstruction surgeries. The study evaluates postoperative analgesic effect of ropivacaine with adjuvant dexmedetomidine following postoperative ultrasound-guided ACB.

Methods

105 randomized subjects received ultrasound-guided ACB using 15 mL of 0.5% ropivacaine, with 0.5 µg kg^-1 of dexmedetomidine administered perineurally (Group II), intravenously (Group III) or none (Group I). Primary outcome included 24 hours' total morphine consumption postoperatively. Secondary outcomes included haemodynamics and adverse effects.

Results

The postoperative total morphine consumption was significantly reduced till 4 hours in II 0.57 mg (0.98 (0-3)) (p = 0.011) and up to 6 hours in Group III 0.77 mg (1.00 (0-4)) (p = 0.004) compared to Group I. The postoperative total morphine consumption was comparable at 24 hours in Group III 3.57 mg (1.73 (0-8)) and Group II 3.34 mg (1.92 (07)) (p = 1.000). The visual analogue scale (VAS) scores were comparable in all the three groups at all the time intervals studied (p > 0.05). There were no adverse effects observed during the study.

Conclusion

Use of perineural dexmedetomidine with LA for ACB in the postoperative period resulted in significant reduction in total morphine consumption in initial 4 hours as compared to 6 hours with intravenous (IV) dexmedetomidine.

The Efficacy of Regional Anesthesia Techniques to Control Postoperative Pain After Total Knee Arthroplasty

BACKGROUND

Choosing the most effective type of anesthesia for controlling postoperative pain is paramount for improving patient outcomes and patient satisfaction. Most often, the type of anesthesia selected is dependent on the duration and type of surgical procedure and anesthesiologist/surgeon preference. Using a combination of regional anesthesia techniques, however, remains the cornerstone of multimodal analgesia for postoperative pain management after total knee arthroplasty.

PURPOSE

The purpose of this study was to determine what regional anesthesia techniques and/or combinations of regional anesthesia techniques provided the best postoperative pain control in patients who had undergone a total knee arthroplasty.

METHODS

Retrospective chart review.

RESULTS

Patients who received a single-shot regional anesthetic reported significantly more postoperative opiate consumption and requested pain medication significantly sooner than patients who received multimodal techniques of regional analgesia.

CONCLUSION

This study found support for the use of multimodal analgesia techniques for optimum postoperative pain management after total knee arthroplasty.

Continuous Adductor Canal Blocks Provide Superior Ambulation and Pain Control Compared to Epidural Analgesia for Primary Knee Arthroplasty: A Randomized, Controlled Trial

BACKGROUND

Adductor canal blocks (ACBs) are an alternative to femoral nerve blocks that minimize lower extremity weakness. However, it is unclear whether this block will provide analgesia that is equivalent to techniques, such as epidural analgesia. The purpose of this randomized controlled trial was to compare continuous ACBs with epidural analgesia for primary total knee arthroplasty.

METHODS

Following institutional review board approval, 145 patients were randomized to 1 of 3 groups: combined spinal-epidural (CSE), spinal + continuous ACB (CACB), or general + CACB. Epidural analgesia was used postoperatively in the CSE group, and an adductor canal catheter was used in the CACB groups. Power analysis determined that 84 patients per group were needed to demonstrate a 35% increase in ambulation with an alpha of 0.05 at a power of 90%.

RESULTS

At interim analysis, 13 patients were removed for protocol deviations, leaving 45 in CSE, 41 in spinal + CACB and 46 in general + CACB groups. Patient demographics were similar in all comparisons suggesting appropriate randomization. Patients in the CACB groups walked further on postoperative day 1, 2, and 3 (P = .02). Mean daily pain scores were lower in the CACB groups (4.1 CSE, 3.0 spinal + CACB, 3.4 general + CACB, P = .009). There was no significant difference in total opioid consumption between groups (158 morphine equivalents CSE, 149 spinal + CACB, and 172 general + CACB). More patients reported being "very satisfied" in CACB groups (68% general + CACB, 63% spinal + CACB, and 36% CSE; P = .001).

CONCLUSION

Continuous adductor analgesia provides superior ambulation, lower pain scores, faster discharge, and greater patient satisfaction when compared to epidural analgesia for primary total knee arthroplasty.

A comparative analysis of femoral nerve block with adductor canal block following total knee arthroplasty: A systematic literature review

Background:

Patients undergoing total knee arthroplasty suffer from moderate-to-severe postoperative pain resulting in immobility-related complications and prolonged hospitalization. Femoral nerve block is associated with reduction in the quadriceps strength and increasing incidence of falls. Adductor canal block has been shown to be as effective as femoral nerve block without causing quadriceps weakness.

Objectives:

To compare outcomes of studies comparing adductor canal block and femoral nerve block in patients undergoing primary total knee arthroplasty.

Data Sources:

Original articles, published between July 2013 and April 2017, comparing the above interventions.

Study Eligibility Criteria, Participants, and Interventions:

Comparison of outcome measures of all original articles shortlisted by the PUBMED and Google Scholar databases search using key words, “adductor canal block; femoral nerve block; total knee arthroplasty; total knee replacement.”

Study Appraisal and Synthesis Methods:

The primary outcome measures reviewed were: pain scores; interventional failure; post-operative opioid consumption; patient fall or near fall during postoperative rehabilitation; and length of stay.

Results:

The opioid consumption was found to be comparable with both the interventions on the first and second postoperative day. Patients administered adductor canal block had better quadriceps power, longer ambulation distance, and shorter length of hospital stay.

Limitations:

Of the studies reviewed five were retrospective and thus data quality amongst the studies may have been compromised.

Conclusions and Implications of Key Findings:

Mobilization and ambulation, which are both important for recovery after total knee arthroplasty are both inhibited less by adductor canal block.

Analgesic Efficacy of Adductor Canal Block in Total Knee Arthroplasty: A Meta-analysis and Systematic Review

The aim of this meta‐analysis and systematic review of randomized controlled trials (RCTs) was to evaluate the efficacy and safety of adductor canal block (ACB) for early postoperative pain management in patients undergoing total knee arthroplasty (TKA). Relevant manuscripts comparing ACB with saline or femoral nerve block (FNB) in TKA patients were searched for in the databases of PubMed, EMBASE, and Cochrane library. The outcomes assessed included cumulative analgesic consumption, pain at rest or during movement, ability to ambulate, quadriceps strength, and complications (nausea, vomiting or sedation). For continuous outcomes, pooled effects were measured using weighted mean difference (WMD) or standard mean difference (SMD), together with 95% confidence intervals (CIs). For outcomes without sufficient data for synthesis, qualitative interpretation of individual studies was summarized. Finally, 11 RCTs involving 675 patients met the inclusion criteria. The pooled results showed that ACB resulted in less postoperative analgesic consumption than saline (WMD, −12.84 mg; 95% CI, −19.40 mg to −6.27 mg; P < 0.001) and less pain at rest or during activity. No conclusions could be drawn regarding ability to ambulate and quadriceps strength, because only one study reported these variables. Most studies comparing ACB and FNB reported similar effects on postoperative analgesic consumption (WMD, −0.56 mg; 95% CI, −8.05 mg to 6.93 mg; P = 0.884) and pain; however, ability to ambulate and quadriceps strength were significantly better with ACB (SMD, 0.99; 95% CI, 0.04–1.94; P = 0.041). Additionally, ACB did not increase the rate of complications. Our results suggest that, compared with saline, ACB decreases analgesic consumption and offers short‐term advantages in terms of pain relief. Compared with FNB, ACB was associated with better ability to ambulate and quadriceps strength.

Post-operative analgesia using intermittent vs. continuous adductor canal block technique: a randomized controlled trial

BACKGROUND AND OBJECTIVES

Intermittent boluses for neural blockade provide better post-operative analgesia when compared to continuous infusion. However, these techniques of administration have not yet been compared while performing adductor canal block (ACB). We compared intermittent vs. continuous ACB for managing post-operative pain following anterior cruciate ligament (ACL) reconstruction. The primary endpoint was total morphine consumption for 24 h post-operatively in both the groups. Secondary outcomes included evaluation of pain scores and opioid-related side effects.

METHODS

After ethics board approval, subjects presenting for ACL reconstruction were randomized to receive either continuous ACB (n = 25) with 0.5% ropivacaine infusing at 2.5 ml/h or intermittent boluses (n = 25) of 15 ml of 0.5% ropivacaine every 6 h. Total morphine consumption 24 h following surgery was recorded in each group.

RESULTS

Fifty subjects completed this study. The mean 24-h total morphine consumption in the intermittent group, [11.36 (6.82) mg], was significantly reduced compared with the continuous group, [23.40 (10.45) mg] (P < 0.001). The mean visual analogue scale (VAS) pain score at rest and on knee flexion was significantly reduced in the intermittent group at 4, 6, 8, and 12 h compared with the continuous group.

CONCLUSION

Intermittent ACB allowed significantly reduced consumption of morphine for 24 h in the post-operative period compared with continuous ACB when identical doses of ropivacaine were used in each group.

Continuous adductor canal block versus continuous femoral nerve block after total knee arthroplasty for mobilisation capability and pain treatment: a randomised and blinded clinical trial

INTRODUCTION

Continuous femoral nerve blocks for total knee arthroplasty can cause motor weakness of the quadriceps muscle and thus prevent early mobilisation. Perioperative falls may result as an iatrogenic complication. In this randomised and blinded trial, we tested the hypothesis that a continuous adductor canal block is superior to continuous femoral nerve block regarding mobilisation ('timed up-and-go' test and other tests) after total knee arthroplasty under general anaesthesia.

METHODS

In our study, we included patients scheduled for unilateral knee arthroplasty under general anaesthesia into a blinded and randomised trial. Patients were allocated to a continuous adductor canal block (CACB) or a continuous femoral nerve block (CFNB) for three postoperative days (POD 1-3); with a bolus of 15 ml ropivacaine 0.375%, followed by continuous infusion of ropivacaine 0.2% and patient-controlled bolus administration. Both groups received an additional continuous sciatic nerve block as well as a multimodal systemic analgesic treatment. The primary outcome parameter was mobilisation capability, assessed by 'timed up-and-go' (TUG) test. Analgesic quality, need for opioid rescue and local anaesthetic consumption were also assessed.

RESULTS

Forty-two patients were included and analysed (21 patients per group). No significant difference was noted in respect to mobilisation at POD 3 (TUG [s]: CACB 45, CFNB 51). It is worth saying that pain scores (numeric rating scale, NRS) were similar in both groups at POD 3 {rest [median (interquartile range)]: CACB 0 (0-3), CFNB 1 (0-3); stress: CACB 4 (2-5), CFNB 3 (2-4)}.

CONCLUSIONS

Concerning the mobilisation capability, we did not actually observe a superior effect of CACB compared with CFNB technique in our patients following total knee arthroplasty. Moreover, no difference was observed concerning analgesia quality.

Femoral nerve block versus adductor canal block for postoperative pain control after anterior cruciate ligament reconstruction: A randomized controlled double blind study

Background:

The objective of this study was to evaluate the reliability of the postoperative pain control using adductor canal block (ACB) compared that using the femoral nerve block (FNB) in patients with anterior cruciate ligament reconstructions (ACLR).

Materials and methods:

One hundred and twenty-eight patients who had been scheduled to patellar graft ACLR were included in this double blind study, and were randomly allocated into two groups; group ACB and group FNB (64 patients each). All patients received general anesthesia. At the end of the surgery, patients in group FNB received a FNB and those in group ACB received an ACB. The postoperative pain (visual analog scale [VAS]) and muscle weakness were assessed in the postoperative care unit and every 6 h thereafter for 24 h. The total morphine requirements were also recorded.

Results:

Patients in group ACB had significantly higher VAS (at 18 h and 24 h), higher morphine consumption, but significantly less quadriceps weakness than those in group FNB.

Conclusion:

In patients with patellar graft ACLR, the ACB can maintain a higher quadriceps power, but with lesser analgesia compared with the FNB.

Adductor Canal Blockade Following Total Knee Arthroplasty-Continuous or Single Shot Technique? Role in Postoperative Analgesia, Ambulation Ability and Early Functional Recovery: A Randomized Controlled Trial

Total knee arthroplasty (TKA) can be associated with severe pain in early postoperative period. Adductor canal block may provide optimal analgesia following TKA. However, ideal regimen for administration whether continuous or single shot is yet undefined. We prospectively randomized 90 patients in continuous and single shot adductor canal blockade groups. Postoperative VAS (visual analog scale for pain) score was significantly better at all times in continuous than single shot technique (P<0.001). However, ambulation ability (Timed Up & Go, 10m walk, 30s chair) and early functional recovery (active SLR, ambulation with walker, staircase competency, ambulation distance and maximal flexion at discharge) showed no statistical significant difference. Continuous adductor canal blockade was superior to single shot block in terms of pain control but was similar for early functional recovery.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Adductor canal block for postoperative pain treatment after revision knee arthroplasty: a blinded, randomized, placebo-controlled study

Background

Revision knee arthroplasty is assumed to be even more painful than primary knee arthroplasty and predominantly performed in chronic pain patients, which challenges postoperative pain treatment. We hypothesized that the adductor canal block, effective for pain relief after primary total knee arthroplasty, may reduce pain during knee flexion (primary endpoint: at 4 h) compared with placebo after revision total knee arthroplasty. Secondary endpoints were pain at rest, morphine consumption and morphine-related side effects.

Methods

We included patients scheduled for revision knee arthroplasty in general anesthesia into this blinded, placebo-controlled, randomized trial. Patients were allocated to an adductor canal block via a catheter with either ropivacaine or placebo; bolus of 0.75% ropivacaine/saline, followed by infusion of 0.2% ropivacaine/saline. Clinicaltrials.gov ID: NCT01191593.

Results

We enrolled 36 patients, of which 30 were analyzed. Mean pain scores during knee flexion at 4 h (primary endpoint) were: 52±22 versus 71±25 mm (mean difference 19, 95% CI: 1 to 37, P = 0.04), ropivacaine and placebo group respectively. When calculated as area under the curve (1–8 h/7 h) pain scores were 55±21 versus 69±21 mm during knee flexion (P = 0.11) and 39±18 versus 45±23 mm at rest (P = 0.43), ropivacaine and placebo group respectively. Groups were similar regarding morphine consumption and morphine-related side effects (P>0.05).

Conclusions

The only statistically significant difference found between groups was in the primary endpoint: pain during knee flexion at 4 h. However, due to a larger than anticipated dropout rate and heterogeneous study population, the study was underpowered.

Trial Registration

Clinicaltrials.gov NCT01191593

Adductor canal blockade for moderate to severe pain after arthroscopic knee surgery: a randomized controlled trial

BACKGROUND

The analgesic effect of the adductor canal block (ACB) after knee surgery has been evaluated in a number of trials. We hypothesized that the ACB would provide substantial pain relief to patients responding with moderate to severe pain after arthroscopic knee surgery.

METHODS

Fifty subjects with moderate to severe pain after arthroscopic knee surgery were enrolled in this placebo-controlled, blinded trial. All subjects received two ACBs; an initial ACB with either 30 ml ropivacaine 7.5 mg/ml (n = 25) (R group) or saline (n = 25) (C group) and after 45 min a second ACB with the opposite study medication, according to randomization. Primary outcome was pain during 45 degrees active flexion of the knee at 45 min after the first block, assessed on a 0-100 mm visual analogue scale. Secondary outcome measures were: pain at rest and during flexion of the knee, worst pain experienced during a 5-m walk, patient's evaluation of muscle strength during walk, and amount of sufentanil administered during the 90-min study period.

RESULTS

Regarding primary outcome, mean pain score difference between groups was 34 (95% CI: 25 to 44) mm, P < 0.001, in favour of the R group. At rest, mean pain score difference was 32 (23 to 41) mm, P < 0.001, and during walk: 21 (6 to 36) mm, P = 0.01 in favour of the R group. There were no differences between groups regarding other secondary outcome measures.

CONCLUSION

The ACB is a relevant option for patients with moderate to severe pain after arthroscopic knee surgery.