Single-injection or continuous femoral nerve block for total knee arthroplasty?

Continuous femoral nerve block as pain management following total knee arthroplasty: a systematic review

INTRODUCTION

The present systematic review evaluated the current level of I evidence on continuous femoral nerve block (FNB) as pain management following total knee arthroplasty (TKA), comparing different drugs.

MATERIALS AND METHODS

This study followed the 2020 PRISMA guidelines. PubMed, Embase and Web of Science were accessed in November 2024. All clinical studies concerning continuous FNB for pain management following TKA were considered.

RESULTS

Data from 22 RCTs were retrieved. The drugs included in the analyses were levobupivacaine, bupivacaine and ropivacaine in isolation or combined with prilocaine or dexmedetomidine. A statistically significant difference was found in VAS at rest in postoperative day (POD) 0 (p < 0.01): the bupivacaine group demonstrated the highest values, and the ropivacaine combined with dexmedetomidine group had the lowest values. No other statistically significant difference in VAS at rest was found for any group in POD 1, 2, and 3 (p = 0.1, p = 0.1, and p = 0.4, respectively). The groups receiving ropivacaine combined with dexmedetomidine and prilocaine had the lowest values of VAS during activity in POD2 (p < 0.01), while in POD3 the groups receiving ropivacaine combined with prilocaine and the bupivacaine one had the lowest values (p < 0.01). No significant difference was found in VAS during activity between any group in POD 0 (p = 0.4) and POD 1 (p = 0.3).

CONCLUSION

Ropivacaine combined with dexmedetomidine might be the best compound for continuous femoral nerve block to manage pain following TKA during the first PODs. Further high-quality investigations are necessary to validate these findings in clinical settings.

Management of Postoperative Pain Following Primary Total Knee Arthroplasty: A Level I Evidence-Based Bayesian Network Meta-Analysis

Background: Postoperative pain management after total knee arthroplasty (TKA) is crucial for promoting early recovery. Advances in pain management techniques have significantly improved outcomes after TKA. Recently, multimodal analgesia has emerged as a key concept in pain management following TKA, using regional anaesthesia to reduce narcotic use and minimise narcotic-related side effects. This Bayesian network meta-analysis compared different treatment options for the management of postoperative pain following primary TKA. Methods: This study was conducted following the 2020 PRISMA statement. In January 2025, all randomised controlled trials (RCTs) related to postoperative pain management following TKA were accessed. Pain reported on postoperative days (PODs) 1-3 was evaluated. Results: Data from 7199 patients were retrieved. Of these, 63.2% (4232 of 6691) were women, and the mean age was 66.7 ± 3.1 years. The mean length of follow-up was 10.2 ± 18.3 weeks. At baseline, comparability was confirmed for age (p = 0.1), BMI (p = 0.8), and visual analogue scale (VAS, p = 0.1). On POD 1, single-shot SNB/three-in-one block was associated with a lower VAS, followed by continuous intra-articular analgesia/local infiltration analgesia (LIA)/posterior capsule infiltration (PCI) and continuous femoral nerve block (FNB)/intermittent SNB. On POD 2, continuous intra-articular analgesia/LIA/PCI was associated with a lower VAS, followed by continuous FNB/PCI and single-shot femoral triangle block (FTB)/single-shot infiltration between the popliteal artery and capsule of the knee (IPACK). On POD 3, continuous ACB was associated with a lower VAS, followed by continuous intra-articular analgesia/LIA/PCI and continuous FNB/PCI. Conclusions: Continuous intra-articular analgesia/LIA/PCI was associated with the best pain control following primary TKA. Multimodal analgesia, which incorporates peripheral nerve blockade and periarticular injections, has become a key concept in contemporary pain management following TKA.

The efficacy of liposomal bupivacaine in parasacral ischial plane block for pain management after total knee arthroplasty: a randomized controlled trial

BACKGROUND

Utilizing liposomal bupivacaine (LB) for postoperative analgesia post-total knee arthroplasty (TKA) is prevalent. However, its effectiveness in pain control, specifically in the parasacral ischial plane block (PIPB) post-TKA, remains unknown.

METHODS

This single-center, double-blinded, randomized controlled trial recruited patients scheduled for unilateral TKA. Forty-five patients were randomly assigned in a 1:1 ratio to receive 133 mg (Group A) or 266 mg (Group B) LB using the block randomization method. The PIPB effectiveness was assessed by evaluating changes in sensory and motor functions. The primary outcome was the cumulative area under the curve (AUC) of the Numerical Rating Scale (NRS) at rest within 72 h postoperatively. All patients were included in the analyses of analgesic efficacy, rehabilitation quality, and adverse events.

RESULTS

Between January 30, 2024, and May 1, 2024, 45 patients were enrolled and randomly assigned to Group A (n = 22) and Group B (n = 23). A significant between-group difference was observed in the NRS-AUC0-72 h at rest postoperatively (132.3 ± 19.7 vs. 97.3 ± 19.1, p = 0.001), but none was observed in NRS-AUC0-72 h during activity (p = 0.642). Kaplan-Meier survival analysis revealed significant between-group differences in the median onset times of sensory [60 vs. 35(min), p < 0.0001] and motor blocks [85 vs. 50(min), p < 0.0001]. The onset time of sensory block was notably shorter than that of motor block in both groups. No significant variance was observed in the median regression time for the sensory block. A significant between-group difference in the rescue analgesic dosage was observed on the first postoperative day [43.1 vs. 27.2(mg), p = 0.009], with no significant differences in the subsequent two days or the total amount. No significant between-group differences were found in adverse events or rehabilitation quality.

CONCLUSION

LB used in the PIPB was effective for analgesia at rest post-TKA, with 266 mg demonstrating superiority. Trial RegistrationThe randomized controlled trial was registered in the Chinese Clinical Trial Registry (https://www.chictr.org.cn/, No: ChiCTR2400079606).

Non-pulmonary complications of intrathecal morphine administration: a systematic review and meta-analysis with meta-regression

BACKGROUND

Intrathecal morphine provides effective analgesia for a range of operations. However, widespread implementation into clinical practice is hampered by concerns for potential side-effects. We undertook a systematic review, meta-analysis, and meta-regression with the primary objective of determining whether a threshold dose for non-pulmonary complications could be defined and whether an association could be established between dose and complication rates when intrathecal morphine is administered for perioperative or obstetric analgesia.

METHODS

We systematically searched the literature for randomised controlled trials comparing intrathecal morphine vs control in patients undergoing any type of surgery under general or spinal anaesthesia, or women in labour. Primary outcomes were rates of postoperative nausea and vomiting, pruritus, and urinary retention within the first 24 postoperative hours, analysed according to doses (1-100 μg; 101-200 μg; 201-500 μg; >500 μg), type of surgery, and anaesthetic strategy. Trials were excluded if doses were not specified.

RESULTS

Our analysis included 168 trials with 9917 patients. The rates of postoperative nausea and vomiting, pruritus, and urinary retention were significantly increased in the intrathecal morphine group, with an odds ratio (95% confidence interval) of 1.52 (1.29-1.79), P<0.0001; 6.11 (5.25-7.10), P<0.0001; and 1.73 (1.17-2.56), P=0.005, respectively. Meta-regression could not establish an association between dose and rates of non-pulmonary complications. There was no subgroup difference according to surgery for any outcome. The quality of evidence was low (Grading of Recommendations Assessment, Development, and Evaluation [GRADE] system).

CONCLUSIONS

Intrathecal morphine significantly increased postoperative nausea and vomiting, pruritus, and urinary retention after surgery or labour in a dose-independent manner.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42023387838).

Single-bolus injection of local anesthetic, with or without continuous infusion, for interscalene brachial plexus block in the setting of multimodal analgesia: a randomized controlled unblinded trial

INTRODUCTION

Previous trials favored a continuous interscalene brachial plexus block over a single injection for major shoulder surgery. However, these trials did not administer a multimodal analgesic regimen. This randomized, controlled unblinded trial tested the hypothesis that a continuous infusion of local anesthetic for an interscalene brachial plexus block still provides superior analgesia after major shoulder surgery when compared with a single injection in the setting of multimodal analgesia, inclusive of intravenous dexamethasone, magnesium, acetaminophen and ketorolac.

METHODS

Sixty patients undergoing shoulder arthroplasty or arthroscopic rotator cuff repair were randomized to receive a bolus of ropivacaine 0.5%, 20 mL, with or without a continuous infusion of ropivacaine 0.2% 4-8 mL/hour, for an interscalene brachial plexus block. Patients were provided with intravenous morphine patient-controlled analgesia. The primary outcome was cumulative intravenous morphine consumption at 24 hours postoperatively. Secondary outcomes included pain scores at rest and on movement, and functional outcomes, measured over 48 hours after surgery.

RESULTS

Median (IQR) cumulative intravenous morphine consumption at 24 hours postoperatively was 10 mg (4-24) in the continuous infusion group and 14 mg (8-26) in the single injection group (p=0.74). No significant between-group differences were found for any of the secondary outcomes.

CONCLUSIONS

A continuous infusion of local anesthetic for an interscalene brachial plexus block does not provide superior analgesia after major shoulder surgery when compared with a single injection in the setting of multimodal analgesia, inclusive of intravenous dexamethasone, magnesium, acetaminophen and ketorolac. The findings of this study are limited by performance and detection biases.

TRIAL REGISTRATION NUMBER

NCT04394130.

Comparing preoperative and postoperative dexamethasone effects on analgesia duration in shoulder surgery

Dexamethasone is commonly used as an adjuvant to prolong peripheral nerve block analgesia, but the optimal timing is unclear. This randomized equivalence trial tested whether preoperative versus postoperative intravenous dexamethasone have equivalent analgesic effects when combined with interscalene brachial plexus block for shoulder surgery. 168 patients were randomized to receive 5 mg dexamethasone either preoperatively or postoperatively. The primary outcome was duration of analgesia, analyzed for equivalence with a 2-h margin. The mean durations were equivalent between groups (11.5 h preoperative versus 10.7 h postoperative). The confidence intervals fell within the equivalence margin. There were no other clinically significant differences in secondary outcomes like time to first analgesia, motor recovery, opioid consumption, blood glucose, or complications. In conclusion, as an adjuvant for nerve block, preoperative and postoperative intravenous dexamethasone provide equivalent analgesic duration, allowing for flexibility in clinical use. This addresses previous uncertainty about timing while demonstrating equivalent efficacy.

Significantly earlier ambulation and reduced risk of near-falls with continuous infusion nerve blocks: a retrospective pilot study of adductor canal block compared to femoral nerve block in total knee arthroplasty

Background

Near-falls should be detected to prevent falls related to the earlier ambulation after Total knee arthroplasty (TKA). The quadriceps weakness with femoral nerve block (FNB) has led to a focus on adductor canal block (ACB). We purposed to examine the risk of falls and the earlier ambulation in each continuous infusion nerve block.

Methods

Continuous infusion nerve block (FNB or ACB) was performed until postoperative day (POD) 2 or 3. Pain levels and falls/near-falls with knee-buckling were monitored from POD 1 to POD 3. The score on the manual muscle test, MMT (0 to 5, 5 being normal), of the patients who could ambulate on POD 1, was investigated.

Results

A total of 73 TKA cases, 36 FNB and 37 ACB, met the inclusion criteria. No falls were noted. But episodes of near-falls with knee-buckling were witnessed in 14 (39%) cases in the FNB group and in 4 (11%) in the ACB group (p = 0.0068). In the ACB group, 81.1% of patients could ambulate with parallel bars on POD 1, while only 44.4% of FNB patients could do so (p = 0.0019). The quadriceps MMT values in the ACB group was 2.82, significantly higher than 1.97 in the FNB group (p = 0.0035). There were no significant differences in pain as measured with a numerical rating scale (NRS) and rescue analgesia through POD 3.

Conclusion

ACB was associated with significantly less knee-buckling and earlier ambulation post-TKA, with better quadriceps strength. Our study indicated the incidence of falls and near-falls with continuous infusion nerve blocks, and support the use of ACB to reduce the risk of falls after TKA. It is suggested that a certain number of the patients even with continuous ACB infusion should be considered with the effect of motor branch to prevent falls.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05735-6.

Review on Nerve Blocks Utilized for Perioperative Total Knee Arthroplasty Analgesia

Total Knee Arthroplasty (TKA) is an increasingly common procedure performed for advanced osteoarthritis. Optimal perioperative pain management strategies are critical for early mobilization and shorter hospital stays in TKA. Peripheral nerve blocks commonly used in TKA perioperative analgesia including individual and combined femoral, obturator, sciatic, lumbar plexus, and adductor canal nerve blocks. Overall, the safety profile varies depending on which block is utilized, but the current evidence suggests when optimally chosen and delivered, peripheral nerve blocks may provide a safe, effective option for perioperative analgesia. Determining optimal analgesic regimens for total knee arthroplasty is critical to improve postoperative pain, patient satisfaction, decreasing opioid usage, recovery times and functional outcomes, and as such, peripheral nerve blocks may represent a viable option to supplement analgesic requirements in the perioperative period.

Efficacy and safety of intrathecal morphine for analgesia after lower joint arthroplasty: a systematic review and meta-analysis with meta-regression and trial sequential analysis

Widespread adoption of intrathecal morphine into clinical practice is hampered by concerns about its potential side‐effects. We undertook a systematic review, meta‐analysis and trial sequential analysis with the primary objective of determining the efficacy and safety of intrathecal morphine. Our secondary objective was to determine the dose associated with greatest efficacy and safety. We also assessed the impact of intrathecal morphine on respiratory depression. We systematically searched the literature for trials comparing intrathecal morphine with a control group in patients undergoing hip or knee arthroplasty under spinal anaesthesia. Our primary efficacy outcome was rest pain score (0–10) at 8–12 hours; our primary safety outcome was the rate of postoperative nausea and vomiting within 24 hours. Twenty‐nine trials including 1814 patients were identified. Rest pain score at 8–12 hours was significantly reduced in the intrathecal morphine group, with a mean difference (95%CI) of −1.7 (−2.0 to −1.3), p < 0.0001 (19 trials; 1420 patients; high‐quality evidence), without sub‐group differences between doses (p = 0.35). Intrathecal morphine increased postoperative nausea and vomiting, with a risk ratio (95%CI) of 1.4 (1.3–1.6), p < 0.0001 (24 trials; 1603 patients; high‐quality evidence). However, a sub‐group analysis by dose revealed that rates of postoperative nausea and vomiting within 24 hours were similar between groups at a dose of 100 µg, while the risk significantly increased with larger doses (p value for sub‐group difference = 0.02). Patients receiving intrathecal morphine were no more likely to have respiratory depression, the risk ratio (95%CI) being 0.9 (0.5–1.7), p = 0.78 (16 trials; 1173 patients; high‐quality evidence). In conclusion, there is good evidence that intrathecal morphine provides effective analgesia after lower limb arthroplasty, without an increased risk of respiratory depression, but at the expense of an increased rate of postoperative nausea and vomiting. A dose of 100 µg is a ‘ceiling’ dose for analgesia and a threshold dose for increased rate of postoperative nausea and vomiting.

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.

Combination of femoral triangle block and infiltration between the popliteal artery and the capsule of the posterior knee (iPACK) versus local infiltration analgesia for analgesia after anterior cruciate ligament reconstruction: a randomized controlled triple-blinded trial

BACKGROUND AND OBJECTIVES

Femoral triangle block and local infiltration analgesia are two effective analgesic techniques after anterior cruciate ligament reconstruction. Recently, the iPACK block (infiltration between the popliteal artery and the capsule of the posterior knee) has been described to relieve posterior knee pain. This randomized controlled triple-blinded trial tested the hypothesis that the combination of femoral triangle block and iPACK provides superior analgesia to local infiltration analgesia after anterior cruciate ligament reconstruction.

METHODS

Sixty patients undergoing anterior cruciate ligament reconstruction received general anesthesia and were randomly allocated to two groups: femoral triangle block and iPACK under ultrasound guidance or local infiltration analgesia. For each group, a total of 160 mg of ropivacaine was injected. Postoperative pain treatment followed a predefined protocol with intravenous morphine patient-controlled analgesia, acetaminophen, and ibuprofen. The primary outcome was cumulative intravenous morphine consumption at 24 hours postoperatively. Secondary pain-related outcomes included pain scores (Numeric Rating Scale out of 10) measured at 2 and 24 hours postoperatively. Functional outcomes, such as range of motion and quadriceps strength, were also recorded at 24 postoperative hours, and at 4 and 8 postoperative months.

RESULTS

Cumulative intravenous morphine consumption at 24 hours postoperatively was significantly reduced in the femoral triangle block and iPACK group (femoral triangle block and iPACK: 9.7 mg (95% CI: 6.7 to 12.7); local infiltration analgesia: 17.0 mg (95% CI: 11.1 to 23.0), p=0.03). Other pain-related and functional-related outcomes were similar between groups.

CONCLUSIONS

The combination of femoral triangle block and iPACK reduces intravenous morphine consumption during the first 24 hours after anterior cruciate ligament reconstruction, when compared with local infiltration analgesia, without effect on other pain-related, early, or late functional-related outcomes.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT03680716).

The analgesic efficacy of iPACK after knee surgery: A systematic review and meta-analysis with trial sequential analysis

STUDY OBJECTIVE

The novel infiltration between the popliteal artery and the capsule of the posterior knee (iPACK) has been described to relieve posterior knee pain after knee surgery. The study objective is to determine whether iPACK provides analgesia after knee surgery when compared with a control group.

DESIGN

Systematic review, meta-analysis and trial sequential analysis.

SETTING

Operating room, postoperative recovery area and ward, up to 24 postoperative hours.

PATIENTS

Patients scheduled for knee surgery under general or spinal anaesthesia.

INTERVENTIONS

We searched five electronic databases for randomized controlled trials comparing iPACK with a control group.

MEASUREMENTS

The primary outcome was rest pain score scores on a visual analogue scale (VAS) of 0-10 at 12 h postoperatively, analysed according to the nature of surgery (total knee arthroplasty vs. anterior cruciate ligament reconstruction) and the use of multimodal analgesia. Secondary outcomes included rest and dynamic pain scores, intravenous morphine-equivalent consumption at 2 h and 24 h, and functional outcomes including ambulation distance and range of motion at discharge.

MAIN RESULTS

Six trials involving 687 patients were included, all of which received total knee arthroplasty only. When compared with a control group, iPACK significantly reduced rest pain scores at 12 h, with a mean difference (95% CI) of -1.0 (-1.5 to -0.5), I² = 93%, p = 0.0003, without subgroup differences for postoperative multimodal analgesia (p = 0.15). Secondary pain outcomes were inconsistently improved with iPACK. Functional outcomes were either similar between groups or had clinically unimportant differences. The overall quality of evidence was moderate.

CONCLUSIONS

There is moderate level evidence that iPACK might provide analgesia for posterior pain after total knee arthroplasty when compared with a control group at 12 h, but was not associated with any other meaningful benefits. Based on these results, there is currently limited evidence supporting the use of iPACK as a complement to adductor canal block for analgesia after total knee arthroplasty.

Perioperative analgesia after intrathecal morphine or local infiltration anesthesia for total knee replacement: A protocol for randomized controlled trial

OBJECTIVE

We perform this protocol for randomized controlled trial to compare the efficacy of intrathecal morphine and local infiltration anesthesia (LIA) in the treatment of the postoperative pain after total knee replacement (TKR).

METHODS

This is a randomized controlled, single center trial which was performed from March 2019 to March 2020. This trial is conducted according to the SPIRIT Checklist of randomized researches. It is authorized via the Ethics Committee of Beijing Friendship Hospital (2019-P2-050-01). Eighty participants who undergo TKR were randomized into 2 groups. Intrathecal morphine group: 0.1 mg of the morphine was intrathecally injected, and the spinal anesthetic was injected at the same time in the group LIA; In the LIA group: the knee joint was infiltrated with epinephrine, ketorologic acid and ropivacaine in the process of operation, and the identical mixture was injected 2 bolus through the intraarticular catheter after operation. The main outcome variables were the visual analog scale and the consumption amount of opioid every 6-hour interval within 2 days postoperatively. The secondary outcome variables were the side effects associated with opioid, the length of hospital stay, motion range, and the loss of blood collected by the closed suction drainage. All the required analyses were carried out via applying the SPSS for Windows Version 19.0.

RESULTS

The clinical outcome variables between groups were shown in .

CONCLUSION

This protocol will provide the evidence on which technique can achieve better analgesia after TKR.

Interscalene brachial plexus block for surgical repair of clavicle fracture: a matched case-controlled study

BACKGROUND

Innervation of the clavicle is complex and debated, with scarce data on the analgesic and clinical impact of regional anaesthesia after surgical repair of clavicle fracture.

METHODS

In order to assess the analgesic efficiency of an interscalene brachial plexus block (ISB) for surgical repair of clavicle fracture, 50 consecutive patients scheduled for surgical fixation of middle/lateral clavicle fracture under general anaesthesia with ISB were prospectively enrolled. This cohort was compared to a historical control of 76 retrospective patients without regional block. The primary outcome was total intravenous morphine equivalent consumption at 2 postoperative hours. To assess the ISB impact, both an overall cohort analysis and a case-matched analysis with each ISB-treated patient matched to a Non-ISB-treated patient was performed. Matching employed a 1-to-1, nearest-neighbour approach using the Mahalanobis metric.

RESULTS

In the overall cohort, patients with ISB had significantly lower i.v. morphine equivalent consumption at 2 postoperative hours (0.7 mg (95% CI 0.1 to 1.2) versus controls 8.8 mg (95% CI 7.1 to 10.4); P <  0.0001). These results persisted after case-matching the cohorts (mean difference for the primary outcome: 8.3 mg (95% CI 6.5 to 10.0); P <  0.001).

CONCLUSIONS

ISB provides effective analgesia after surgical fixation of middle and lateral clavicle fracture. These results should help physicians in establishing an analgesic strategy for this type of surgery. Further research is needed to identify the optimal regional technique for medial third clavicle fractures and the clinically relevant contributions of the cervical and brachial plexus.

TRIAL REGISTRATION

Clinicaltrials.gov - NCT02565342, October 1st 2015.

The efficacy of continuous versus single-injection femoral nerve block in Total knee Arthroplasty: a systematic review and meta-analysis

Background

Continuous femoral nerve block (cFNB) has been developed to extend the analgesic effect since the efficacy of single-injection femoral nerve block (sFNB) is often limited to approximately 16–24 h. The aim of this meta-analysis was to validate the add-on effect of cFNB in the setting of a multimodal analgesic protocol.

Methods

We performed a comprehensive literature review on Web of Science, Embase, the Cochrane Library and PubMed. Eight randomized controlled trials (N = 626) that compared the efficacy of cFNB with sFNB were included. The primary outcome domains consist of visual analog scale (VAS) score at postoperative 24 and 48 h. The secondary outcome domains include opioid consumption, length of hospital stay and incidence of nausea.

Results

Our analysis revealed that cFNB was associated with a lower VAS score at 24 h (SMD: -0.277;95% CI − 0.503 to − 0.05). However, the difference of VAS score did not meet the minimal clinically importance difference for total knee arthroplasty (TKA). VAS score at 48 h was similar between the cFNB and sFNB group. The cFNB group was associated with less amount of opioids consumed at both 24(SMD: -1.056;95% CI − 1.737 to − 0.375) and 48 h(SMD: -1.040;95% CI − 1.790 to − 0.289). Length of hospital stay and incidence of nausea were similar between the two groups.

Conclusion

In the setting of a multimodal analgesic protocol, patients might benefit from cFNB with regards to a reduced need of opioids in the early postoperative period. However, we did not find a clinically significant difference in pain scores at different time points between the cFNB and sFNB group.

Level of evidence

I; meta-analysis.

Analgesic Impact of Single-Shot Versus Continuous Femoral Nerve Block After Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

INTRODUCTION

Efficient pain management after total knee arthroplasty will accelerate functional recovery and reduce the length of hospital stay. The femoral nerve block is increasingly used in clinical practice owing to its favorable analgesic efficacy. However, the effect of continuous femoral nerve block compared to single-shot femoral nerve block remains controversial.

METHODS

Three databases (Pubmed, Embase and Cochrane Library) were searched for randomized controlled trials up to April 2019. Seven studies with 525 patients were included in this analysis.

RESULTS

The pooled estimates showed that the continuous femoral nerve block could relieve the pain at rest [standardized mean differences with 95% confidence intervals 1.12 (0.63-1.60), I² = 57%, p < 0.00001] and physical therapy [standardized mean differences with 95% confidence intervals 1.05 (0.47-1.63), I² = 71%, p = 0.0004] on postoperative day 1 and reduce total morphine consumption on postoperative day 1 [mean differences with 95% confidence intervals 16.15 (13.75-18.54), I² = 46%, p < 0.00001] and 2 [mean differences with 95% confidence intervals 7.02 (4.82-9.22), I² = 35%, p < 0.00001]. There is no significant difference in pain scores at rest and physical therapy on postoperative day 2 and 3, in Western Ontario and McMaster University Arthritis Index scores (p = 0.12), the length of hospital stay (p = 0.94) and the incidence of nausea and vomiting (p = 0.09).

CONCLUSION

We conclude that the continuous femoral nerve block is more effective than single-shot femoral nerve block after total knee arthroplasty, which provides objective evidence of pain management for anesthetists.

Are perioperative interventions effective in preventing chronic pain after primary total knee replacement? A systematic review

OBJECTIVES

For many people with advanced osteoarthritis, total knee replacement (TKR) is an effective treatment for relieving pain and improving function. Features of perioperative care may be associated with the adverse event of chronic pain 6 months or longer after surgery; effects may be direct, for example, through nerve damage or surgical complications, or indirect through adverse events. This systematic review aims to evaluate whether non-surgical perioperative interventions prevent long-term pain after TKR.

METHODS

We conducted a systematic review of perioperative interventions for adults with osteoarthritis receiving primary TKR evaluated in a randomised controlled trial (RCT). We searched The Cochrane Library, MEDLINE, Embase, PsycINFO and CINAHL until February 2018. After screening, two reviewers evaluated articles. Studies at low risk of bias according to the Cochrane tool were included.

INTERVENTIONS

Perioperative non-surgical interventions; control receiving no intervention or alternative treatment.

PRIMARY AND SECONDARY OUTCOME MEASURES

Pain or score with pain component assessed at 6 months or longer postoperative.

RESULTS

44 RCTs at low risk of bias assessed long-term pain. Intervention heterogeneity precluded meta-analysis and definitive statements on effectiveness. Good-quality research provided generally weak evidence for small reductions in long-term pain with local infiltration analgesia (three studies), ketamine infusion (one study), pregabalin (one study) and supported early discharge (one study) compared with no intervention. For electric muscle stimulation (two studies), anabolic steroids (one study) and walking training (one study) there was a suggestion of more clinically important benefit. No concerns relating to long-term adverse events were reported. For a range of treatments there was no evidence linking them with unfavourable pain outcomes.

CONCLUSIONS

To prevent chronic pain after TKR, several perioperative interventions show benefits and merit further research. Good-quality studies assessing long-term pain after perioperative interventions are feasible and necessary to ensure that patients with osteoarthritis achieve good long-term outcomes after TKR.

Adductor canal block versus local infiltration analgesia for postoperative pain after anterior cruciate ligament reconstruction: a single centre randomised controlled triple-blinded trial

BACKGROUND

Both the adductor canal block (ACB) and local infiltration analgesia (LIA) are effective analgesic techniques after anterior cruciate ligament (ACL) reconstruction, but they have never been compared head-to-head. This randomised controlled triple-blinded trial tested the hypothesis that ACB provides superior analgesia to LIA after ACL reconstruction, with additional focus on postoperative functional outcomes.

METHODS

Of 104 enrolled ACL reconstruction patients receiving general anaesthesia, 52 were randomly allocated to either ACB under ultrasound guidance or LIA. For each intervention, ropivacaine 0.5%, 20 ml was injected. Postoperative pain treatment followed a predefined protocol with i.v. patient-controlled morphine, paracetamol, and ibuprofen. The primary outcome was cumulative i.v. morphine consumption at 24 h after operation. Secondary pain-related outcomes included resting and dynamic pain scores (numeric rating scale out of 10) measured 2, 24, and 48 h after operation and cumulative i.v. morphine consumption 2 and 48 h after operation. Early function-related outcomes evaluated were quadriceps strength, walking distance, and range of motion, all measured 24 and 48 h after operation. Late function-related outcomes were concentric quadriceps strength, single-hop test, triple-hop test, cross-over test, and Y balance test, measured at 4 and 8 postoperative months.

RESULTS

Cumulative i.v. morphine consumption at 24 h was similar between groups (ACB group: 17.1 mg [95% confidence interval, CI: 13.1, 21.2]; LIA group: 17.7 mg [95% CI: 13.2, 22.6], P=0.84). Similarly, no differences between groups were seen in the secondary pain- or function-related outcomes.

CONCLUSIONS

ACB and LIA result in equivalent postoperative opioid consumption with similar impact on postoperative pain scores and functional outcomes.

CLINICAL TRIAL REGISTRATION

NCT02524652.

Comparison of peripheral nerve blockade characteristics between non-diabetic patients and patients suffering from diabetic neuropathy: a prospective cohort study

Animal data have demonstrated increased block duration after local anaesthetic injections in diabetic rat models. Whether the same is true in humans is currently undefined. We, therefore, undertook this prospective cohort study to test the hypothesis that type-2 diabetic patients suffering from diabetic peripheral neuropathy would have increased block duration after ultrasound-guided popliteal sciatic nerve block when compared with patients without neuropathy. Thirty-three type-2 diabetic patients with neuropathy and 23 non-diabetic control patients, scheduled for fore-foot surgery, were included prospectively. All patients received an ultrasound-guided popliteal sciatic nerve block with a 30 ml 1:1 mixture of lidocaine 1% and bupivacaine 0.5%. The primary outcome was time to first opioid request after block procedure. Secondary outcomes included the time to onset of sensory blockade, and pain score at rest on postoperative day 1 (numeric rating scale 0-10). These outcomes were analysed using an accelerated failure time regression model. Patients in the diabetic peripheral neuropathy group had significantly prolonged median (IQR [range]) time to first opioid request (diabetic peripheral neuropathy group 1440 (IQR 1140-1440 [180-1440]) min vs. control group 710 (IQR 420-1200 [150-1440] min, p = 0.0004). Diabetic peripheral neuropathy patients had a time ratio of 1.57 (95%CI 1.10-2.23, p < 0.01), experienced a 59% shorter time to onset of sensory blockade (median time ratio 0.41 (95%CI 0.28-0.59), p < 0.0001) and had lower median (IQR [range]) pain scores at rest on postoperative day 1 (diabetic peripheral neuropathy group 0 (IQR 0-1 [0-5]) vs. control group 3 (IQR 0-5 [0-9]), p = 0.001). In conclusion, after an ultrasound-guided popliteal sciatic nerve block, patients with diabetic peripheral neuropathy demonstrated reduced time to onset of sensory blockade, with increased time to first opioid request when compared with patients without neuropathy.

The Use of Liposomal Bupivacaine Administered With Standard Bupivacaine in Ankle Fractures Requiring Open Reduction Internal Fixation: A Single-Blinded Randomized Controlled Trial

OBJECTIVES

To determine the efficacy of liposomal bupivacaine compared to placebo for postoperative pain control in patients undergoing operative fixation of ankle fractures.

DESIGN

Prospective single-blinded randomized control trial.

SETTING

Academic Medical Center.

PATIENTS/PARTICIPANTS

After Institutional Review Board (IRB) approval, 76 patients who sustained an acute ankle fracture (OTA/AO 44A-C) requiring operative fixation met inclusion criteria.

INTERVENTION

Patients were randomly assigned to 1 of 2 groups, control (local intraoperative sterile saline injection under general anesthesia) or interventional (local intraoperative liposomal bupivacaine and bupivacaine injection under general anesthesia). Injections were administered in a standardized fashion and included injection of a 1:1 mixture of a 40 mL solution consisting of 1.3% Exparel and sterile saline (interventional) or a 40 mL injection of normal saline (control) into the surrounding periosteal, peritendinous, surrounding muscles and subcutaneous tissue of the surgical incision(s).

MAIN OUTCOME MEASUREMENTS

Pain medications administered and pain according to the Visual Analogue Scale was recorded at scheduled postoperative time points: 4, 24, 48, 72, and 336 hours (14 days).

RESULTS

Thirty-nine patients were randomized to the control group and 37 to the interventional group (mean age = 42 ± 15 years), with no statistically significant differences between groups with regards to severity of injury and patient demographics. Pain scores were significantly lower in the interventional group versus control up to 2 weeks after surgery. Percocet ingestion at 4 hours was significantly lower in the interventional group (0.7 vs. 1.3, P = 0.004), while it approached significance at 48 hours postoperatively (2.8 vs. 3.69, P = 0.07). No other significant differences were noted for Percocet ingestion postoperatively at other time points assessed. The overall satisfaction with pain control was not statistically different between the 2 groups (P = 0.93).

CONCLUSION

Local intraoperative infiltration of liposomal bupivacaine administered with standard bupivacaine for ankle fractures requiring Open Reduction Internal Fixation (ORIF) affords improved pain relief in the immediate postoperative period resulting in a reduction in Percocet ingestion, with resultant effects seen up to 2 days postoperatively. Continued investigation of this drug for use with extremity fractures is warranted.

LEVEL OF EVIDENCE

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

Comparison of 2 Analgesia Modalities in Total Knee Replacement Surgery: Is There an Effect on Knee Function Rehabilitation?

BACKGROUND We compared the effects of continuous femoral nerve block (CFNB) and continuous intraarticular block (CIAB) on pain, functional recovery and adverse effects after total knee arthroplasty (TKA). MATERIAL AND METHODS We prospectively randomized 54 patients undergoing TKA into 2 groups: CFNB (Group F) and CIAB (Group I). Surgery was performed under spinal anesthesia. All patients received patient-controlled analgesia (PCA) with morphine, diclofenac, and acetaminophen for the first 72 h postoperatively. Pain was assessed with a visual analog scale (VAS), 48-h morphine consumption and 72-h local anesthetic dosage were recorded, motor blockade was assessed, maximum range of motion (ROM) was measured, and adverse effect profiles were recorded. RESULTS There was no significant difference in postoperative pain at rest, in passive motion, active motion, or active movement (2-min walk test (2MWT)) between study groups. Group I had less opioid usage in the first 24 h postoperatively (p<0.05). No significant difference was found between the groups in the postoperative local anesthetic dosage (p>0.05). Significantly lower scores of Bromage scale in Group I in 72 h after surgery (p<0.05) were found. Group I had superior passive maximum ROM in 1 month after surgery and superior active maximum ROM on day 7 and at 1 month after surgery (p<0.05). CONCLUSIONS Both CFNB and CIAB are effective postoperative analgesia methods after TKA. CIAB leads to lower postoperative opioid usage in the first 24 h, lower motor blockade in the first 72 h, and better knee function on day 7 and at 1 month after surgery.

Use of the cumulative sum method (CUSUM) to assess the learning curves of ultrasound-guided continuous femoral nerve block

BACKGROUND

Although ultrasound is a basic competence for anaesthesia residents (AR) there is few data available on the learning process. This prospective observational study aims to assess the learning process of ultrasound-guided continuous femoral nerve block and to determine the number of procedures that a resident would need to perform in order to reach proficiency using the cumulative sum (CUSUM) method.

METHODS

We recruited 19 AR without previous experience. Learning curves were constructed using the CUSUM method for ultrasound-guided continuous femoral nerve block considering 2 success criteria: a decrease of pain score>2 in a [0-10] scale after 15minutes, and time required to perform it.

RESULTS

We analyse data from 17 AR for a total of 237 ultrasound-guided continuous femoral nerve blocks. 8/17 AR became proficient for pain relief, however all the AR who did more than 12 blocks (8/8) became proficient. As for time of performance 5/17 of AR achieved the objective of 12minutes, however all the AR who did more than 20 blocks (4/4) achieved it.

CONCLUSIONS

The number of procedures needed to achieve proficiency seems to be 12, however it takes more procedures to reduce performance time. The CUSUM methodology could be useful in training programs to allow early interventions in case of repeated failures, and develop competence-based curriculum.

Electrophysiological Study of Femoral Nerve Function After a Continuous Femoral Nerve Block for Anterior Cruciate Ligament Reconstruction: A Randomized, Controlled Single-Blind Trial

BACKGROUND

A continuous femoral nerve block (CFNB) is an effective analgesic treatment after anterior cruciate ligament (ACL) reconstruction but may result in transient femoral nerve injuries and quadriceps muscle weakness, which in turn contribute to worsened functional outcomes.

PURPOSE

To compare electrophysiological criteria of a femoral nerve injury as well as functional and pain-related outcomes after ACL reconstruction when analgesia was provided by a CFNB or intravenous patient-controlled analgesic of morphine (IV PCA).

STUDY DESIGN

Randomized controlled clinical trial; Level of evidence, 1.

METHODS

A total of 74 patients scheduled for ACL reconstruction were randomized to receive a CFNB before surgery, followed by a ropivacaine infusion for 2 days and oxycodone, or IV PCA. The primary outcome was the rate of femoral nerve injuries at 4 weeks postoperatively, defined as a reduction of the compound muscle action potential (CMAP) area from the vastus medialis muscle after supramaximal femoral nerve stimulation at the groin, associated with an absent H-reflex of the femoral nerve and signs of vastus medialis muscle denervation. Secondary functional outcomes were quadriceps muscle strength, active flexion range, and distance walked, as measured on postoperative days 1 and 2. Secondary pain-related outcomes were IV morphine consumption and pain scores at rest and on movement in phase 1 recovery and on postoperative days 1 and 2.

RESULTS

No patients met the electrophysiological criteria of a femoral nerve injury. The mean CMAP area at 4 weeks was equivalent in both the CFNB and IV PCA groups (47 ± 16 mV·ms and 51 ± 13 mV·ms, respectively; P = .50). While no differences were detected in functional outcomes or pain scores, the consumption of an IV morphine equivalent was reduced by the administration of a CFNB in phase 1 recovery (6 ± 5 mg and 13 ± 7 mg, respectively; P = .0003), on postoperative day 1 (6 ± 7 mg and 19 ± 17 mg, respectively; P = .0005), and on postoperative day 2 (11 ± 10 mg and 19 ± 17 mg, respectively; P = .03) compared with an IV PCA.

CONCLUSION

Despite prior contrary reports, a CFNB did not result in femoral nerve injuries or worsened functional outcomes after ACL reconstruction. The improvement of analgesia with a CFNB was only marginal and not clinically relevant beyond 24 hours. Registration: NCT01321138 ( ClinicalTrials.gov identifier).

Potential superiority of periarticular injection in analgesic effect and early mobilization ability over femoral nerve block following total knee arthroplasty

PURPOSE

Pain management after total knee arthroplasty (TKA) should permit early knee mobilization with minimal pain. Periarticular injection (PAI) with local anaesthetics has been recently discussed as a protocol of pain control. The purpose of this review of the literature was to evaluate the efficacy of PAI in comparison with femoral nerve block (FNB).

METHODS

A literature search was performed in PubMed, EMBASE, the OVID database and the Cochrane Library databases. Risk of bias was assessed using the Cochrane collaboration tool. Outcomes of interest included narcotic consumption, pain score, early mobilization ability, length of stay and adverse effects or events.

RESULTS

Research identified 918 articles, of which six with a total of 284 knees, met the inclusion criteria and were eligible for the current study. Conflicting evidence was found in terms of narcotic consumption on the postoperative day 1 and early mobilization ability. Total narcotic consumption, pain score in the first 2 days after surgery, length of stay and adverse effects or events showed no difference between two groups. Lower pain score on the day of surgery was detected after PAI. When compared to continuous FNB, patients in PAI group showed a tendency to achieving better ability of early mobilization.

CONCLUSIONS

In consideration of its relatively simple practice and its potential in analgesic effects or early mobilization ability, PAI had superiority to FNB in the management of pain control after TKA. Before PAI could be widely used in clinical practice after TKAs, further investigations would be necessary to confirm or refute our observed results and to unify the protocol of PAI.

LEVEL OF EVIDENCE

I.

A Comparison of Single Shot Adductor Canal Block Versus Femoral Nerve Catheter for Total Knee Arthroplasty

The aim of this study was to compare perioperative analgesia provided by single-injection adductor canal block (ACB) to continuous femoral nerve catheter (FNC) when used in a multimodal pain protocol for total knee arthroplasty (TKA). A retrospective cohort study compared outcome data for 148 patients receiving a single-injection ACB to 149 patients receiving an FNC. The mean length of stay (LOS) in the ACB group was 2.67 (±0.56) and 3.01 days (±0.57) in the FNC group (P<0.0001). The median ambulatory distances for the adductor group were further than the femoral group for postoperative days 1 (P<0.0001) and 2 (P=0.01). Single-injection ACB offered similar pain control and earlier discharge compared to continuous FNC in patients undergoing TKA.

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.

The ethics of placebo-controlled trials: methodological justifications

The use of placebo controls in clinical trials remains controversial. Ethical analysis and international ethical guidance permit the use of placebo controls in randomized trials when scientifically indicated in four cases: (1) when there is no proven effective treatment for the condition under study; (2) when withholding treatment poses negligible risks to participants; (3) when there are compelling methodological reasons for using placebo, and withholding treatment does not pose a risk of serious harm to participants; and, more controversially, (4) when there are compelling methodological reasons for using placebo, and the research is intended to develop interventions that can be implemented in the population from which trial participants are drawn, and the trial does not require participants to forgo treatment they would otherwise receive. The concept of methodological reasons is essential to assessing the ethics of placebo controls in these controversial last two cases. This article sets out key considerations relevant to considering whether methodological reasons for a placebo control are compelling.