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

Neurological injury following peripheral nerve blocks: a narrative review of estimates of risks and the influence of ultrasound guidance

BACKGROUND

Peripheral nerve injury or post-block neurological dysfunction (PBND) are uncommon but a recognized complications of peripheral nerve blocks (PNB). A broad range of its incidence is noted in the literature and hence a critical appraisal of its occurrence is needed.

OBJECTIVE

In this review, we wanted to know the pooled estimates of PBND and further, determine its pooled estimates following various PNB over time. Additionally, we also sought to estimate the incidence of PBND with or without US guidance.

EVIDENCE REVIEW

A literature search was conducted in six databases. For the purposes of the review, we defined PBND as any new-onset sensorimotor disturbances in the distribution of the performed PNB either attributable to the PNB (when reported) or reported in the context of the PNB (when association with a PNB was not mentioned). Both prospective and retrospective studies which provided incidence of PBND at timepoints of interest (>48 hours to <2 weeks; >2 weeks to 6 weeks, 7 weeks to 5 months, 6 months to 1 year and >1 year durations) were included for review. Incidence data were used to provide pooled estimates (with 95% CI) of PBND at these time periods. Similar estimates were obtained to know the incidence of PBND with or without the use of US guidance. Additionally, PBND associated with individual PNB were obtained in a similar fashion with upper and lower limb PNB classified based on the anatomical location of needle insertion.

FINDINGS

The overall incidence of PBND decreased with time, with the incidence being approximately 1% at <2 weeks' time (Incidence per thousand (95% CI)= 9 (8; to 11)) to approximately 3/10 000 at 1 year (Incidence per thousand (95% CI)= 0. 3 (0.1; to 0.5)). Incidence of PBND differed for individual PNB with the highest incidence noted for interscalene block.

CONCLUSIONS

Our review adds information to existing literature that the neurological complications are rarer but seem to display a higher incidence for some blocks more than others. Use of US guidance may be associated with a lower incidence of PBND especially in those PNBs reporting a higher pooled estimates. Future studies need to standardize the reporting of PBND at various timepoints and its association to PNB.

Femoral Nerve Block and Local Instillation Analgesia Associated With More Reliable Efficacy in Regional Anesthesia Interventions Within 24 Hours Following Anterior Cruciate Ligament Reconstruction: A Network Meta-analysis

PURPOSE

To assess the relative effectiveness of different regional anesthetic techniques (peripheral nerve blocks, local instillation analgesia, including intra-articular, subcutaneous, and periarticular infiltration) in patients undergoing anterior cruciate ligament reconstruction (ACLR).

METHODS

PubMed, Embase, Cochrane Library, and Web of Science databases were searched from their inception to December 31, 2020. The search was supplemented by manual review of relevant reference lists. Randomized controlled trials of participants after ACLR that compared regional anesthesia interventions were selected. The 2 coprimary outcomes were (1) rest pain scores and (2) cumulative oral morphine equivalent consumption on day 1 (24 hours) post-ACLR. Data were pooled using a Bayesian framework.

RESULTS

Of 759 records identified, 46 trials were eligible, evaluating 9 interventions in 3,171 patients. Local instillation analgesia (LIA), including intra-articular, subcutaneous, and periarticular infiltration, had significant improvement in pain relief as compared with placebo (-0.91; 95% CrI -1.45 to -0.37). Femoral nerve block (FNB) also showed significant effects in relieving pain as compared with placebo (-0.70; 95% 95% credible interval [CrI] -1.28 to -0.12). Compared with placebo, a significant reduction in opioid consumption was found in LIA (mean difference -13.29 mg; 95% CrI -21.77 to -4.91) and FNB (mean difference -13.97 mg; 95% CrI -24.71 to -3.04). Femoral and sciatic nerve block showed the greatest ranking for pain relief and opioid consumption without significant evidence (P > .05) to support superiority in comparison with placebo, respectively.

CONCLUSIONS

Our meta-analysis shows that FNB and LIA can significantly diminish postoperative pain and reduce opioid consumption following ACLR compared with placebo in the setting of regional anesthesia, and femoral and sciatic nerve block may be the number 1 top-ranked analgesic technique despite high uncertainty.

LEVEL OF EVIDENCE

I, Systematic review of Level I studies.

Network meta-analysis of the analgesic effectiveness of regional anaesthesia techniques for anterior cruciate ligament reconstruction

Anterior cruciate ligament reconstruction can cause moderate to severe acute postoperative pain. Despite advances in our understanding of knee innervation, consensus regarding the most effective regional anaesthesia techniques for this surgical population is lacking. This network meta-analysis compared effectiveness of regional anaesthesia techniques used to provide analgesia for anterior cruciate ligament reconstruction. Randomised trials examining regional anaesthesia techniques for analgesia following anterior cruciate ligament reconstruction were sought. The primary outcome was opioid consumption during the first 24 h postoperatively. Secondary outcomes were: rest pain at 0, 6, 12 and 24 h; area under the curve of pain over 24 h; and opioid-related adverse effects and functional recovery. Network meta-analysis was conducted using a frequentist approach. A total of 57 trials (4069 patients) investigating femoral nerve block, sciatic nerve block, adductor canal block, local anaesthetic infiltration, graft-donor site infiltration and systemic analgesia alone (control) were included. For opioid consumption, all regional anaesthesia techniques were superior to systemic analgesia alone, but differences between regional techniques were not significant. Single-injection femoral nerve block combined with sciatic nerve block had the highest p value probability for reducing postoperative opioid consumption and area under the curve for pain severity over 24 h (78% and 90%, respectively). Continuous femoral nerve block had the highest probability (87%) of reducing opioid-related adverse effects, while local infiltration analgesia had the highest probability (88%) of optimising functional recovery. In contrast, systemic analgesia, local infiltration analgesia and adductor canal block were each poor performers across all analgesic outcomes. Regional anaesthesia techniques that target both the femoral and sciatic nerve distributions, namely a combination of single-injection nerve blocks, provide the most consistent analgesic benefits for anterior cruciate ligament reconstruction compared with all other techniques but will most likely impair postoperative function. Importantly, adductor canal block, local infiltration analgesia and systemic analgesia alone each perform poorly for acute pain management following anterior cruciate ligament reconstruction.

Femoral Nerve Blockade Does Not Lead to Subjective Functional Deficits After Anterior Cruciate Ligament Reconstruction

INTRODUCTION

Anterior cruciate ligament reconstruction (ACLR) ranks among the most common surgeries performed in civilian as well as military orthopedic settings. Regional anesthesia, and the femoral nerve block (FNB) in particular, has demonstrated efficacy in reducing postoperative pain and opioid use after ACLR, however concerns linger about possible impaired functional outcomes. The purpose of the current investigation was to assess International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) scores at 6 to 12 months after ACLR in patients who did (FNB) and did not (NoFNB) receive a perioperative FNB.

MATERIALS AND METHODS

All patients undergoing unilateral ACLR in the study period were reviewed in this institutional process improvement analysis. The primary outcome was prospectively collected IKDC-SKF scores obtained at 6-12 months post-surgery. Demographic and surgical information collected as potential covariates included age, sex, body mass index (BMI), preoperative IKDC-SKF score, use of an FNB, use of another (not femoral nerve) block, American Society of Anesthesiologists (ASA) score, graft type (auto vs. allograft), concomitant meniscus or cartilage procedures, tobacco use, tourniquet time, and primary vs. revision surgery. Assuming a 1:2 ratio of patients who did not vs. did receive FNBs and a clinically meaningful difference of 7 points on the IKDC-SKF, 112 patients were required for 80% power. A regression model averaging approach examined the relationships between covariates and postoperative IKDC-SKF scores.

RESULTS

One hundred nineteen patients met inclusion criteria (FNB 79 and NoFNB 40). The cohorts were significantly different in several factors including BMI, ASA level, graft type, and other peripheral nerve blocks, which were controlled for through regression modeling. Regressions with model averaging examined the relationship between treatment groups and postoperative IKDC-SKF scores, along with other potential predictor variables. Estimated adjusted marginal differences in postoperative IKDC-SKF scores from the best-fitting model revealed a very small 0.66-point mean (P = .86) difference between NoFNB and FNB groups that was not statistically significant. Those who reported tobacco use had a 10.51 point (P = .008) lower mean postoperative IKDC-SKF score than those who did not report tobacco use. Every 1-point increase in the preoperative IKDC-SKF score was associated with a 0.28-point (P = .02) increase in the postsurgical IKDC-SKF score.

CONCLUSIONS

Active tobacco use may negatively impact short-term subjective patient-reported outcomes after ACLR, as reported by the IKDC-SKF. Lower preoperative scores are also associated with significantly lower postoperative IKDC-SKF scores while the use of a FNB was not associated with lower postoperative scores. The negative association between tobacco use and patient-reported functional outcomes after ACLR lends further support to tobacco cessation programs within the military.

Rupture, reconstruction, and rehabilitation: A multi-disciplinary review of mechanisms for central nervous system adaptations following anterior cruciate ligament injury

BACKGROUND

Despite surgical reconstruction and extensive rehabilitation, persistent quadriceps inhibition, gait asymmetry, and functional impairment remain prevalent in patients after anterior cruciate ligament (ACL) injury. A combination of reports have suggested underlying central nervous system adaptations in those after injury govern long-term neuromuscular impairments. The classic assumption has been to attribute neurophysiologic deficits to components of injury, but other factors across the continuum of care (e.g. surgery, perioperative analgesia, and rehabilitative strategies) have been largely overlooked.

OBJECTIVE

This review provides a multidisciplinary perspective to 1) provide a narrative review of studies reporting neuroplasticity following ACL injury in order to inform clinicians of the current state of literature and 2) provide a mechanistic framework of neurophysiologic deficits with potential clinical implications across all phases of injury and recovery (injury, surgery, and rehabilitation) RESULTS: Studies using a variety of neurophysiologic modalities have demonstrated peripheral and central nervous system adaptations in those with prior ACL injury. Longitudinal investigations suggest neurophysiologic changes at spinal-reflexive and corticospinal pathways follow a unique timecourse across injury, surgery, and rehabilitation.

CONCLUSION

Clinicians should consider the unique injury, surgery, anesthesia, and rehabilitation on central nervous system adaptations. Therapeutic strategies across the continuum of care may be beneficial to mitigate maladaptive neuroplasticity in those after ACL injury.

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.

Femoral nerve block at time of ACL reconstruction causes lasting quadriceps strength deficits and may increase short-term risk of re-injury

PURPOSE

To determine whether femoral nerve blockade (FNB) at the time of primary ACL reconstruction is associated with meeting isokinetic extension strength return to sport criteria near completion of physical therapy and whether FNB affects 1-year or 2-year risk of ipsilateral ACL graft rupture or contralateral native ACL injury.

METHODS

Three-hundred and sixty patients (n = 244 with FNB, n = 116 no FNB) underwent primary ACL reconstruction. All patients completed rehabilitation and underwent functional strength testing towards the end of knee rehabilitation (mean 5.6 months post-surgery). Association between FNB and isokinetic extension strength limb symmetry index (LSI) (goal LSI ≥ 90% for return to sport) as well as risk of recurrent ACL injury within first or second year after surgery was evaluated.

RESULTS

Ipsilateral or contralateral ACL injury within 2 years occurred in 11.2% of patients with FNB and 5.7% without FNB (p = 0.01). Patients with FNB had higher incidence of ipsilateral graft rupture within the first year after surgery but no difference in graft rupture during the second. Two-year risk of contralateral ACL injury was similar in both groups. At the time of initial testing, patients who received FNB had lower fast isokinetic extension LSI versus patients without FNB and were less likely achieve a goal ≥ 90% LSI; slow extension LSI was unaffected.

CONCLUSION

Use of FNB at the time of primary ACL reconstruction can negatively affect achievement of isokinetic extension strength return to sport criteria. FNB increases risk of graft rupture within the first year after surgery but does not affect re-injury risk during the second. FNB may not be appropriate for use in patients already at high risk of ACL re-injury.

LEVEL OF EVIDENCE

III.

The Influence of Perioperative Nerve Block on Strength and Functional Return to Sports After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Patients often have quadriceps or hamstring weakness after anterior cruciate ligament reconstruction (ACLR), despite postoperative physical therapy regimens; however, little evidence exists connecting nerve blocks and ACLR outcomes.

PURPOSE

To compare muscle strength at return to play in patients who received a nerve block with ACLR and determine whether a specific block type affected subjective knee function.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients were recruited 5 to 7 months after primary, isolated ACLR and completed bilateral isokinetic strength tests of the knee extensor/flexor groups as a single-session return-to-sport test. Subjective outcomes were assessed with the International Knee Documentation Committee (IKDC) score. Strength was expressed as torque normalized to mass (N·m/kg) and limb symmetry index as involved/uninvolved torque. Chart review was used to determine the type of nerve block and graft used. Nerve block types were classified as knee extensor motor (femoral nerve), knee flexor motor (sciatic nerve), or isolated sensory (adductor canal block/saphenous nerve). A 1-way analysis of covariance controlling for graft type was used.

RESULTS

A total of 169 patients were included. Graft type distribution consisted of 102 (60.4%) ipsilateral bone-patellar tendon-bone (BTB) and 67 (39.6%) ipsilateral hamstring tendon. Nerve block type distribution consisted of 38 (22.5%) femoral, 25 (14.8%) saphenous, 45 (26.6%) femoral and sciatic, and 61 (36.1%) saphenous and sciatic. No significant difference was found in knee extensor strength (P = .113) or symmetry (P = .860) between patients with knee extensor motor blocks (1.57 ± 0.45 N·m/kg; 70.1% ± 15.3%) and those without (1.47 ± 0.47 N·m/kg; 69.6% ± 18.8%). A significant difference was found between patients with knee flexor motor blocks (0.83 ± 0.26 N·m/kg) and those without (0.92 ± 0.27 N·m/kg) for normalized knee flexor strength (P = .21) but not knee flexor symmetry (P = .592). Controlling for graft type, there were no differences in subjective knee function (IKDC score) between all nerve block groups (P = .57).

CONCLUSION

Our data showed that use of a sciatic nerve block with ACLR in patients with hamstring and BTB grafts influences persistent knee flexor strength deficits at time of return to sports. Although the cause of postoperative muscular weakness is multifactorial, this study adds to the growing body of evidence suggesting that perioperative nerve blocks affect muscle strength and functional rehabilitation after ACLR.

Effects of adductor canal block versus femoral nerve block in patients with anterior cruciate ligament reconstruction: A protocol for a systematic review and meta-analysis

OBJECTIVE

It is reported that both adductor canal block (ACB) and femoral nerve block (FNB) are commonly used methods for postoperative analgesia in anterior cruciate ligament (ACL) reconstruction. Currently, no record has compared the efficacy of postoperative pain relief and the influence to quadriceps strength between them. This study aims to provide a protocol to compare the efficacy and safety between ACB and FNB for the postoperative analgesia of ACL reconstruction.

METHODS

This study will be performed in accordance with the guideline of the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols. Online databases including PubMed, Embase, Web of Science, Cochrane Library, Wanfang database, and the Chinese National Knowledge Infrastructure database will be systematically searched from their inception up May 31, 2019. All randomized controlled trials will be included in present meta-analysis. The quality of enrolled literatures will be evaluated by using the Cochrane Collaboration Risk of bias Tool. Statistical analysis will be calculated by the Review Manager 5.3.

RESULTS

This review will investigate the efficacy and safety of ACB compared with FNB in patients undergoing ACL reconstruction. The primary outcomes are visual analog scale, cumulative opioid consumption during 24 hours after surgery, numerical rating scale, and the time to first straight-leg raise. The secondary outcomes include maximal voluntary isometric contraction, stretching torque at 3, 6 months' follow-up, and adverse effects.

CONCLUSION

Findings of this systematic review and meta-analysis will summarize the current evidence in postoperative analgesia for ACL reconstruction and also provide implications for clinical practice.

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.

Lower extremity regional anesthesia: essentials of our current understanding

The advent of ultrasound guidance has led to a renewed interest in regional anesthesia of the lower limb. In keeping with the American Society of Regional Anesthesia and Pain Medicine's ongoing commitment to provide intensive evidence-based education, this article presents a complete update of the 2005 comprehensive review on lower extremity peripheral nerve blocks. The current review article strives to (1) summarize the pertinent anatomy of the lumbar and sacral plexuses, (2) discuss the optimal approaches and techniques for lower limb regional anesthesia, (3) present evidence to guide the selection of pharmacological agents and adjuvants, (4) describe potential complications associated with lower extremity nerve blocks, and (5) identify informational gaps pertaining to outcomes, which warrant further investigation.

Femoral nerve block versus fascia iliaca block for pain control in total knee and hip arthroplasty: A meta-analysis from randomized controlled trials

BACKGROUND

This meta-analysis aimed to perform a meta-analysis to compare the efficiency and safety between femoral nerve block (FNB) and fascia iliaca block (FIB) for postoperative pain control in patients undergoing total knee and hip arthroplasties.

METHODS

A systematic search was performed in Medline (1966-2017.05), PubMed (1966-2017.05), Embase (1980-2017.05), ScienceDirect (1985-2017.05) and the Cochrane Library. Inclusion criteria (1) Participants: Only published articles enrolling adult participants that with a diagnosis of end-stage of osteoarthritis and prepared for unilateral TKA or THA; (2) Interventions: The intervention group received FIB for postoperative pain management; (3) Comparisons: The control group was received FNB for postoperative pain control; (4) Outcomes: Visual analogue scale (VAS) scores in different periods, opioids consumption, length of stay and postoperative complications; (5) Study design: clinical randomized control trials (RCTs) were regarded as eligible in our study. Cochrane Hand book for Systematic Reviews of Interventions was used for assessment of the included studies and risk of bias was shown. Fixed/random effect model was used according to the heterogeneity tested by I2 statistic. Sensitivity analysis was conducted and publication bias was assessed. Meta-analysis was performed using Stata 11.0 software.

RESULTS

Five RCTs including 308 patients met the inclusion criteria. The present meta-analysis indicated that there were no significant differences between groups in terms of visual analog scale (VAS) score at 12 hours (SMD = -0.080, 95% CI: -0.306 to 0.145, P = .485), 24 hours (SMD = 0.098, 95% CI: -0.127 to 0.323, P = .393), and 48 hours (SMD = -0.001, 95% CI: -0.227 to 0.225, P = .993). No significant differences were found regarding opioid consumption at 12 hours (SMD = 0.026, 95% CI: -0.224 to 0.275, P = .840), 24 hours (SMD = 0.037, 95% CI: -0.212 to 0.286, P = .771), and 48 hours (SMD = -0.016, 95% CI: -0.265 to 0.233, P = .900). In addition, no significant increase of complications was identified between groups.

CONCLUSION

There is no significant differences of VAS scores at 12-48 hour and opioids consumption at 12-48 hour between two groups following total joint arthroplasty. No increased risk of nausea, vomiting and pruritus was observed in both groups. More high-quality large RCTs with long follow-up period are necessary for proper comparisons of the efficacy and safety of FNB with FIB. The present meta-analysis exists some limitations that should be noted: (1) Only five articles were included in present meta-analysis, although all of them are recently published RCTs, the sample size are relatively small; (2) Functional outcome is an important parameter, due to the insufficiency of relevant data, we cannot perform a meta-analysis. (3) Dose and types of local anesthetics are varied, which may influence the results; (4) The duration of follow up is relatively short which leads to underestimating complications. (5) Publication bias in present meta-analysis may influence the results.