Is continuous catheter adductor canal block better than single-shot canal adductor canal block in primary total knee arthroplasty?: A GRADE analysis of the evidence through a systematic review and meta-analysis

The Effect of Postoperative Single-Injection Adductor Canal Block in Total Knee Arthroplasty Under Spinal Anesthesia With Intraoperative Dexmedetomidine Infusion

Background

Single-injection adductor canal block (SACB) is one of the multimodal pain managements in total knee arthroplasty. The effect of an intrathecal local anesthetic is prolonged with an intraoperative dexmedetomidine infusion. Currently, SACB's effect along with the prolonged spinal anesthesia effect by dexmedetomidine has not been studied elsewhere.

Methods

Seventy-eight patients were randomized to either the SACB group (n = 39) or the control group (n = 39). Spinal anesthesia and continuous infusion of dexmedetomidine were performed intraoperatively. The SACB was performed using 15 mL of either 0.5% ropivacaine or normal saline in postanesthesia care unit postoperatively. Primary endpoint examined the average numerical rating scale (NRS) pain scores at 2, 6, 12, and 24 hours after SACB while resting or moving. The secondary outcomes were the morphine equivalent, postoperative nausea and vomiting score, quadriceps strength, and overall satisfaction score.

Results

The SACB group showed a lower average NRS pain score until 24 hours than the control group (2.4 vs 3.3 resting, 3.4 vs 4.1 moving). Resting and moving NRS scores at 6 and 12 hours were significantly lower in the SACB group, whereas no difference was found at 2, 24, and 48 hours, regardless of movement. The satisfaction score was higher in the SACB group than in the control group (9 [7.3-10.0] vs 7 [5.3-8.8]), and morphine equivalent at 2 hours was lower in the SACB group (2 [1-3]) than in the control group (2.9 [1.6-4]).

Conclusions

SACB provided an additional analgesic effect in patients undergoing total knee arthroplasty under spinal anesthesia with continuous dexmedetomidine intravenous infusion.

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

PURPOSE

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

SOURCE

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

PRINCIPAL FINDINGS

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

CONCLUSION

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

A prospective, randomized trial of liposomal bupivacaine compared to conventional bupivacaine on pain control and postoperative opioid use in adults receiving adductor canal blocks for total knee arthroplasty

BACKGROUND

Total knee arthroplasty (TKA) is a commonly performed procedure to alleviate pain and improve functional limitations caused by end-stage joint damage. Effective management of postoperative pain following TKA is crucial to the prevention of complications and enhancement of recovery. Adductor canal blocks (ACB) with conventional bupivacaine (CB) provide adequate analgesia after TKA, but carry a risk of rebound pain following block resolution. Liposomal bupivacaine (LB) is an extended-release local anesthetic that can provide up to 72 h of pain relief. The objective of this study was to compare postoperative outcomes between ACBs using LB and CB after TKA.

METHODS

This single institution, prospective, randomized, clinical trial enrolled patients scheduled for TKA. Participants were randomized to receive ACB with either LB or CB. Pain scores up to 72 h postoperatively were assessed as the primary outcome. Opioid consumption and length of stay were evaluated as secondary outcomes.

RESULTS

A total of 80 patients were enrolled. Demographic and clinical characteristics were similar between the two groups. LB group showed significantly lower cumulative opioid use during the 72 h evaluated (P = 0.016). There were no differences in pain scores or length of stay between the groups.

CONCLUSION

The study demonstrated that LB ACBs led to significantly lower opioid consumption in the days following TKA without affecting pain scores or length of stay. This finding has important implications for improving postoperative outcomes and reducing opioid use in TKA patients. Previous studies have reported inconsistent results regarding the benefits of LB, highlighting the need for further research.

TRIAL REGISTRATION

This project was retrospectively registered with clinicaltrials.gov ( NCT05635916 ) on 2 December 2022.

Regional anesthesia for geriatric population

Advancements in modern health care over 20 years have substantially increased the average lifespan in developed countries, and the fastest growing population is the elderly population. The proportion of people in Saudi Arabia aged 60 or more is predicted to be 25 percent of the total population of 40 million by the end of 2050. Moreover, the number of people aged 80 or more is expected to reach 1.6 million or 4 percent of the total population in the same period. Improvements in surgical techniques, anesthesia, and intensive care units make surgical interventions in older and sicker patients possible. It is estimated that over half of the population older than 65 years will require surgical intervention at least once during the remainder of their lives. Therefore, elderly patients are becoming an even larger part of anesthetic practice. Regional anesthesia (RA) is frequently used in elderly patients, especially during orthopedic surgery, genitourologic and gynecologic procedures, and hernia repair. Although age can no longer be considered a contraindication to anesthesia and surgery, anesthesia-related morbidity and mortality remain higher among elderly than among young adult surgical patients. Undoubtedly, peripheral nerve (PN) blocks improve analgesia and reduce opioid consumption and their associated side effects. This is beneficial in the perioperative care of elderly patients who may have less physiologic reserve to withstand the side effects of general anesthesia (GA).

Current Trends and Future Directions for Outpatient Total Joint Arthroplasty: A Review of the Anesthesia Choices and Analgesic Options

The aging population and the obesity epidemic have led to an increased rate of joint arthroplasty procedures, specifically total knee arthroplasty and total hip arthroplasty. These surgeries are associated with increased hospital length of stay and, consequently, higher costs. Despite the benefits of outpatient surgery, only a small percentage of total joint arthroplasties (TJAs) are done in this manner. We reviewed the most up-to-date trends for outpatient TJA and discussed essential factors for a successful outpatient program, including the proper patient selection process and best available anesthetic and analgesic options, along with their risks and benefits. Risk stratification tools, such as the Outpatient Arthroplasty Risk Assessment, are helpful for predicting outcomes regarding outpatient TJA, and neuraxial anesthesia should be considered to minimize complications and facilitate early discharge. A multimodal analgesia regimen could be effective for pain management in outpatient TJA, and the currently recommended peripheral nerve blocks for total hip arthroplasty and total knee arthroplasty are the fascia iliaca compartment block and adductor canal block, respectively. However, blocks should be carefully considered for outpatient procedures. Enhanced recovery after surgery (ERAS) protocols help to guide perioperative care teams and allow for improved patient recovery, decreased length of stay, and increased patient satisfaction.

The effects of continuous catheter adductor canal block for pain management in knee replacement therapy: a meta-analysis

PURPOSE

Adductor canal block has emerged as a favourable element of multimodal analgesia regimens for total knee arthroplasty, due to the exclusive sensory blockade it provides. However, it is controversial as to whether a single shot or continuous technique adductor canal block is superior. This meta-analysis examined the effect of both these techniques on pain management associated with total knee arthroplasty.

METHODS

All randomised controlled trials published on Cochrane Library, PubMed, and EMBASE, Scopus, and PsychINFO were systematically searched. The PEDro scale was used to assess the quality of studies. A total of 8 articles, 2 of which were split by subgroup analyses to create 10 studies, with 828 adults were selected for inclusion in the analysis. The mean difference and effect size with a 95% confidence interval (CI) were analysed for the pooled results.

RESULTS

Statistically significant pooled effects of analgesia technique in favour of catheter use were found in the reduction of pain scores and VAS scores, and total rescue analgesia dosage. No significant changes were observed in the hospital stay time. Subgroup analysis revealed that patients with BMI 30 or more reported higher pain scores than those with BMI below 30.

CONCLUSION

Based upon studies that are currently available, our meta-analysis appears to demonstrate that continuous administration of analgesia through an adductor canal catheter provides greater pain reduction in total knee arthroplasty than single shot analgesia. Despite these current findings, future studies with larger sample sizes and greater control of study parameters are required to confirm the current findings.

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.

Positioning the Catheter Tip Anterior or Posterior to the Saphenous Nerve in Continuous Adductor Canal Block: A Mono-Centric Retrospective Comparative Study

Background and Aim

Ultrasound-guided continuous adductor canal block (cACB) is a conventional choice in patients undergoing total knee arthroplasty (TKA) for the management of the postoperative pain. This study aims to compare different catheter tip locations for cACB relative to the saphenous nerve (anteriorly vs posteriorly) in terms of efficacy and complications.

Methods

At the department of Surgical Sciences, Orthopedic Trauma and Emergencies of the University of Naples Federico II (Naples, Italy), between January 2020 and November 2021, retrospective comparative study was executed. Patients planned for TKA were included in the study if they met the follow inclusion criteria: patients undergone TKA; aged 50-85 years; body mass index (BMI) of 18-35 kg/m2; American Society of Anesthesiologists (ASA) physical status classification from I to III; subarachnoid technique for anesthesiology plane; continuous adductor canal block performed by an anesthetist with considerable experience. Patients were assigned to receive cACB with the catheter tip located anteriorly (Group 1, G1) or posteriorly to the saphenous nerve (Group 2, G2). Postoperative pain, ambulation ability, episodes of pump block and rate of catheter dislodgement and leakage were evaluated and analyzed.

Results

Altogether, 102 patients were admitted to the study (48 in G1 and 54 in G2). After the first 8 postoperative hours, in G1 17 patients (35.4%) had a VAS greater than 4, while in group 2 only 3 patients (5.6%) had a VAS greater than 4 (p-value <0.01). All patients of both groups showed ambulation ability in the postoperative period. No episode of leakage was recorded. While the catheter displacement rate was similar in the two groups (2.1% for G1 vs 3.7% for G2; p-value >0.05), the episodes of pump block were significantly less in G2 than in G1 (3.7% vs 20.8%; p-value <0.01).

Conclusion

In cACB for TKA, we found that positioning the catheter tip posteriorly to the saphenous nerve may lead to a greater postoperative analgesia and reduce the risk of pump block compared to placing the catheter tip anteriorly to the nerve.

Peripheral Nerve Block for Pain Management after Total Hip Arthroplasty: A Retrospective Study with Propensity Score Matching

This study aimed to evaluate the effect of a peripheral nerve block (PNB) on immediate postoperative analgesia and the early functional outcomes for patients who underwent total hip arthroplasty (THA). From January 2016 to August 2021, 353 patients who underwent THA were divided into two groups: the patient-controlled analgesia (PCA) group (n = 217) who received only intravenous (IV) analgesia, and others who received IV PCA and PNB (PCA + PNB group) (n = 136). After propensity score matching for age and sex, 136 patients from each group were included in the study. Primary outcomes were the visual analogue scale (VAS) at rest, activity status at postoperative 6, 24, 48 h. Secondary outcomes were functional scores by the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index, Harris Hip Score (HHS) and rescue medications used. The postoperative VAS at 6, 24, 48 h at rest and 6 h at activity were significantly lower in the PCA + PNB group (p = 0.000, 0.001, 0.000, 0.004 in order). There was no significant difference for postoperative 3-month HHS (p = 0.218), except for 3-month WOMAC index (p = 0.001). There were no significant differences for VAS between the PNB methods except femoral nerve block (FNB) and fascia iliaca compartment block (FICB) at postoperative activity 48 h (p = 0.028). There was no significant difference in the total count and amount of rescue medication (p = 0.091, 0.069) and difference in the quadriceps weakness was not noted. Therefore, PNB is beneficial for patients who undergo THA as it provides sufficient postoperative analgesia, especially during immediate postoperative resting pain without quadriceps weakness.

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.

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

BACKGROUND.

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

METHODS.

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

RESULTS.

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

CONCLUSIONS.

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

Same-Day Outpatient Lower-Extremity Joint Replacement: A Critical Analysis Review

➢ The economics of transitioning total joint arthroplasty (TJA) to standalone ambulatory surgery centers (ASCs) should not be capitalized on at the expense of patient safety in the absence of established superior patient outcomes. ➢ Proper patient selection is essential to maximizing safety and avoiding complications resulting in readmission. ➢ Ambulatory TJA programs should focus on reducing complications frequently associated with delays in discharge. ➢ The transition from hospital-based TJA to ASC-based TJA has substantial financial implications for the hospital, payer, patient, and surgeon.

Implementation and Postoperative Management of Continuous Adductor Canal Catheters for Total Knee Arthroplasty to Reduce Surgical Backlog Related to the COVID-19 Pandemic: An Acute Pain Service Nursing Perspective and Educational Resource

PURPOSE

In response to the surgical backlog created by the COVID-19 pandemic and to spare valuable hospital resources, we developed and implemented a continuous adductor canal catheter (CACC) program for total knee arthroplasty (TKA) patients. CACC's offer superior analgesia, decrease opioid use, and increase patient satisfaction while simultaneously promoting a decreased length of hospital stay and even same day discharges. The implementation of analgesia protocols using continuous peripheral nerve catheters and isometric pumps has been described for other surgical procedures and populations; however, the role of the Acute Pain Service Nurse (APS RN) in the implementation of such a program has not been described.

DESIGN

An best practice initiative for TKA patients receiving CACC was developed and implemented for patients recovering both in the hospital and at home.

METHODS

We describe the development and implementation of a CACC program for TKA patients in response to the surgical backlog created by the COVID-19 pandemic from the perspective of the APS RN. We provide a detailed narrative description of our postoperative assessment and experience, and offer practical insights for the postoperative care of these patients. We share the educational resources and assessment tools we developed to ensure consistent, safe, and effective clinical management of CACC patients in the hospital and at home.

FINDINGS

CACCs via elastomeric pumps have been shown to offer significant advances to pain control following TKA, decrease opioid use, enable earlier discharge, and improve patient satisfaction, all of which we observed unequivocally in our patients. In our experience, implementation of a daily telephone follow up by an APS RN for discharged TKA patients with a CACC was crucial for patient safety, patient satisfaction, and reducing emergency phone calls and emergency room visits.

CONCLUSIONS

We anticipate this description will provide an invaluable educational resource for other Acute Pain Service programs as similar outpatient peripheral nerve catheter programs are developed in response to the pandemic.

Femoral 3-in-1 Nerve Block for Total Knee Replacement, an Analgesic Approach Not to Be Neglected. Single Center Experience and Literature Review

OBJECTIVES

Total Knee Replacement Surgery (TKR) is one of the most common elective orthopedic operations. Postoperative pain after total knee replacement, remains a challenge. In this retrospective observational study, we evaluated the effectiveness of 3-in-1 nerve block in patients after total knee arthroplasty compared to standard opioid treatment, and we state the reasons why this approach should still be considered.

METHODS

To evaluate the effectiveness of the 3-in-1 nerve block, we assessed the acute pain service archive and compared the values of the visual analog scale, by separating patients into two groups according to the analgesic regimen they received as per local protocols. In group A, patients received 0.25% bupivacaine through a 3 in 1 block catheter and additional meperidine IM if needed, while in group B they received meperidine every six hours.

RESULTS

Our analysis showed the statistically significant better effectiveness of 3-in-1 nerve block with bupivacaine administration in postoperative TKR pain control compared to repeated administration of meperidine.

CONCLUSION

The results of our study suggest that 3-in-1 nerve block with bupivacaine is an option that must always be considered in order to alleviate post-operative pain after TKR.

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

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

Perineural Liposomal Bupivacaine Is Not Superior to Nonliposomal Bupivacaine for Peripheral Nerve Block Analgesia

BACKGROUND

Liposomal bupivacaine is purported to extend analgesia of peripheral nerve blocks when administered perineurally. However, evidence of the clinical effectiveness of perineural liposomal bupivacaine is mixed. This meta-analysis seeks to evaluate the effectiveness of perineural liposomal bupivacaine in improving peripheral nerve block analgesia as compared with nonliposomal local anesthetics.

METHODS

The authors identified randomized trials evaluating the effectiveness of peripheral nerve block analgesic that compared liposomal bupivacaine with nonliposomal local anesthetics. The primary outcome was the difference in area under the receiver operating characteristics curve (AUC) of the pooled 24- to 72-h rest pain severity scores. Secondary outcomes included postoperative analgesic consumption, time to first analgesic request, incidence of opioid-related side effects, patient satisfaction, length of hospital stay, liposomal bupivacaine side effects, and functional recovery. AUC pain scores were interpreted in light of a minimal clinically important difference of 2.0 cm · h.

RESULTS

Nine trials (619 patients) were analyzed. When all trials were pooled, AUC pain scores ± SD at 24 to 72 h were 7.6 ± 4.9 cm · h and 6.6 ± 4.6 cm · h for nonliposomal and liposomal bupivacaine, respectively. As such, perineural liposomal bupivacaine provided a clinically unimportant benefit by improving the AUC (95% CI) of 24- to 72-h pain scores by 1.0 cm · h (0.5 to 1.6; P = 0.003) compared with nonliposomal bupivacaine. Excluding an industry-sponsored trial rendered the difference between the groups nonsignificant (0.7 cm · h [-0.1 to 1.5]; P = 0.100). Secondary outcome analysis did not uncover any additional benefits to liposomal bupivacaine in pain severity at individual timepoints up to 72 h, analgesic consumption, time to first analgesic request, opioid-related side effects, patient satisfaction, length of hospital stay, and functional recovery. No liposomal bupivacaine side effects were reported.

CONCLUSIONS

Perineural liposomal bupivacaine provided a statistically significant but clinically unimportant improvement in the AUC of postoperative pain scores compared with plain local anesthetic. Furthermore, this benefit was rendered nonsignificant after excluding an industry-sponsored trial, and liposomal bupivacaine was found to be not different from plain local anesthetics for postoperative pain and all other analgesic and functional outcomes. High-quality evidence does not support the use of perineural liposomal bupivacaine over nonliposomal bupivacaine for peripheral nerve blocks.

EDITOR’S PERSPECTIVE

The Impact of Femoral Nerve Anesthesia on Short-Term Clinical Outcomes and Opioid Claims After Total Knee Arthroplasty

Background

The impact of femoral nerve blocks (FNBs) during primary total knee arthroplasty (TKA) on clinical outcomes and pain management remains unclear. The present research investigates the impact that continuous and single-shot FNBs during TKA have on postoperative opioid claims and short-term clinical outcomes.

Methods

An administrative claims database was queried to identify patients who underwent primary TKA with a continuous FNB, single-shot FNB, or no FNB. More than 300,000 patients were analyzed from the database. Rates of opioid claims were compared via achi-square analysis. Incidence of postoperative complications was compared with multivariable logistic regression.

Results

Patients receiving a FNB had a significantly higher risk of falls both at 6 months (odds ratio [OR], 1.30) and 1 year postoperatively (OR, 1.25), as well as readmissions within 90 days (OR, 1.18) compared with patients without FNBs. The FNB cohort exhibited a higher risk of deep vein thrombosis (OR, 1.57), myocardial infarction (OR, 1.79), and cerebrovascular accident (OR, 1.20) during the inpatient stay. Relative to single-shot FNBs, continuous FNBs were associated with a higher risk of readmissions within 90 days and systemic complications, although the risk varied by age, sex, and Charlson Comorbidity Index score. More patients without FNBs filed opioid claims within 1 year postoperatively, but the average total morphine milligram equivalents prescribed was comparable to patients who received FNBs.

Conclusions

FNBs during TKA place patients at a significantly higher risk of falls, readmissions, and systemic complications in the short term. The risk of readmission and systemic complications was higher for continuous FNBs. More patients without FNBs filed opioid claims postoperatively than patients who received FNBs.