Femoral Nerve Block Versus Long-Acting Wound Infiltration in Total Knee Arthroplasty

Liposomal Bupivacaine for Peripheral Nerve Blockade: A Randomized, Controlled, Crossover, Triple-blinded Pharmacodynamic Study in Volunteers

BACKGROUND

Little is known about the pharmacodynamic characteristics of liposomal bupivacaine. Hypothesizing that they would not identify pharmacodynamic differences from plain bupivacaine during the initial period after administration, but would find better long-term pharmacodynamic characteristics, the authors designed a randomized, controlled, triple-blinded, single-center study in volunteers.

METHODS

Volunteers aged 18 to 55 yr (body mass index, 18 to 35 kg/m2) received two ulnar nerve blocks under ultrasound guidance. Using a crossover design with a washout phase of 36 days or more, one block was performed with liposomal and one with plain bupivacaine. Which came first was determined by randomization. Sensory data were collected by pinprick testing and motor data by thumb adduction, either way in comparison with the contralateral arm. Endpoints included success, time to onset, and duration of blockade. Residual efficacy was assessed by the volunteers keeping a diary. Statistical analysis included Wilcoxon signed-rank and exact McNemar's tests, as well as a generalized estimation equation model.

RESULTS

Successful sensory blockade was noted in 8 of 25 volunteers (32%) after liposomal and in 25 of 25 (100%) after plain bupivacaine (P < 0.0001). Significant differences emerged for time to onset, defined as 0% response to pinpricking in four of five hypothenar supply areas (P < 0.0001), and for time from onset to 80% or 20% in one of five areas (P < 0.001; P < 0.001). Carryover effects due to the randomized sequencing were unlikely (estimate, -0.6286; sequence effect, 0.8772; P = 0.474). Self-assessment greater than 3.5 days did reveal, for liposomal bupivacaine only, intermittent but unpredictable episodes of residual sensory blockade.

CONCLUSIONS

The results show that liposomal bupivacaine is not a suitable "sole" drug for intraoperative regional anesthesia. Findings of its limited long-term efficacy add to existing evidence that a moderate effect, at best, should be expected on postoperative pain therapy.

EDITOR’S PERSPECTIVE

Updates on Wound Infiltration Use for Postoperative Pain Management: A Narrative Review

Local anesthetic wound infiltration (WI) provides anesthesia for minor surgical procedures and improves postoperative analgesia as part of multimodal analgesia after general or regional anesthesia. Although pre-incisional block is preferable, in practice WI is usually done at the end of surgery. WI performed as a continuous modality reduces analgesics, prolongs the duration of analgesia, and enhances the patient’s mobilization in some cases. WI benefits are documented in open abdominal surgeries (Caesarean section, colorectal surgery, abdominal hysterectomy, herniorrhaphy), laparoscopic cholecystectomy, oncological breast surgeries, laminectomy, hallux valgus surgery, and radical prostatectomy. Surgical site infiltration requires knowledge of anatomy and the pain origin for a procedure, systematic extensive infiltration of local anesthetic in various tissue planes under direct visualization before wound closure or subcutaneously along the incision. Because the incidence of local anesthetic systemic toxicity is 11% after subcutaneous WI, appropriate local anesthetic dosing is crucial. The risk of wound infection is related to the infection incidence after each particular surgery. For WI to fully meet patient and physician expectations, mastery of the technique, patient education, appropriate local anesthetic dosing and management of the surgical wound with “aseptic, non-touch” technique are needed.

Adductor Canal Block vs Liposomal Bupivacaine Periarticular Injection in Total Knee Arthroplasty: A Randomized Controlled Trial

BACKGROUND

This study compares postoperative pain scores and functional outcomes between liposomal bupivacaine peri-articular injection (LB-PAI) vs a single-shot adductor canal block (ACB) using bupivacaine HCl in patients undergoing primary total knee arthroplasty (TKA).

METHODS

This is a randomized controlled trial of 56 patients who were treated with TKA for arthritis. Patients were randomized to receive an intraoperative LB-PAI (n = 27) or preoperative ACB using bupivacaine HCl (n = 29). Both groups were otherwise given our institutional standard multimodal pain protocol. Data on Visual Analog Scale (VAS) pain scores, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, knee range of motion, postoperative ambulation distance, hospital length of stay, and opioid use were collected. The total cost of each intervention was compared at the conclusion of the study.

RESULTS

Age, gender, or body mass index was similar between groups. Compared to the ACB group, the LB-PAI group trended to lower average VAS pain scores on postoperative days 0, 1, and 2 (average difference [95% confidence interval] = -0.5 [-0.7, 1.7], -1.0 [-0.1, 2.0], -0.2 [-0.8, 1.3]), and identical average VAS pain scores on postoperative days 4 and 7. These differences and all postoperative outcome measures were not statistically significant at any time point. A single 266-milligram vial of liposomal bupivacaine costs $351, and a single-shot ACB costs $893 at our institution.

CONCLUSIONS

This randomized controlled trial shows similar postoperative pain control, functional outcomes, and opioid use between LB-PAI and a single-shot ACB in patients undergoing primary TKA. However, the single-shot ACB costs $542 more than the LB-PAI at our institution.

Comparison of liposomal bupivacaine and 0.5% bupivacaine hydrochloride for control of postoperative pain in dogs undergoing tibial plateau leveling osteotomy

OBJECTIVE

To compare liposome-encapsulated bupivacaine (LEB) and (nonliposomal) 0.5% bupivacaine hydrochloride (0.5BH) for control of postoperative pain in dogs undergoing tibial plateau leveling osteotomy (TPLO).

ANIMALS

33 client-owned dogs.

PROCEDURES

In a randomized clinical trial, dogs undergoing TPLO received LEB (5.3 mg/kg [2.4 mg/lb]) or 0.5BH (1.5 mg/kg [0.68 mg/lb]) by periarticular soft tissue injection. All dogs received carprofen (2.2 mg/kg [1 mg/lb], SC, q 12 h) beginning at extubation. Signs of pain were assessed at extubation and predetermined times up to 48 hours later with the Colorado State University-Canine Acute Pain Scale and Glasgow Composite Pain Scale-Short Form. A pressure nociceptive threshold device was used at the affected stifle joint before surgery and at 5 postoperative time points. Methadone (0.1 mg/kg [0.05 mg/lb], IV) was administered if the Colorado State University pain scale score was ≥ 2 (scale, 0 to 4). Surgical variables; pain scores; pressure nociceptive thresholds; times to first administration of rescue analgesic, first walk, and first meal consumption; and total opioid administration were compared between treatment groups.

RESULTS

28 dogs completed the study. Dogs administered LEB were less likely to require rescue analgesia and received lower amounts of opioids than dogs administered 0.5BH. There were no significant intergroup differences in other measured variables.

CONCLUSIONS AND CLINICAL RELEVANCE

The LEB appeared to provide adequate analgesia after TPLO with lower requirements for opioid treatments, which may allow dogs to be discharged from the hospital earlier than with traditional pain management strategies.

Comprehensive Comparison of Liposomal Bupivacaine with Femoral Nerve Block for Pain Control Following Total Knee Arthroplasty: An Updated Systematic Review and Meta-Analysis

To compare the efficacy of liposomal bupivacaine (LB) and femoral nerve block following total knee arthroplasty, we conducted this systematic review and meta-analysis. 11 trials with 2,908 patients were included in this study. The pooled data demonstrated that total morphine consumption equivalents during the hospital stay was significantly increased in FNB group. In addition, LB has significantly better outcome in view of the postoperative functional recovery, such as the odds of fall, the incidences of straight leg rise (SLR), the number of patients who can walk independently in the day of surgery,the ambulation distance at POD1, the number of patients discharged at POD1. Consistent with the faster functional recovery, liposomal bupivacaine shortens the length of hospital stay. However, there was no significant difference between LB and FNB in terms of Visual Analogue Score (VAS) during the hospital stay. All in all, liposomal bupivacaine has significantly better outcome in view of the postoperative functional recovery and the length of hospital stay compared with femoral nerve block following the total knee arthroplasty.

The Efficacy of Liposomal Bupivacaine Over Traditional Local Anesthetics in Periarticular Infiltration and Regional Anesthesia During Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Since its Food and Drug Administration approval in 2011 as a local anesthetic for postsurgical analgesia, liposomal bupivacaine (LB) has been incorporated into the periarticular injection (PAI) of many knee surgeons. The slow release of this medication from vesicles should significantly extend the duration of its analgesic effect, but current evidence has not clearly demonstrated this benefit.

METHODS

We systematically searched electronic databases including PubMed, MEDLINE, Cochrane Library, EMBASE, ScienceDirect, and Scopus, as well as the Journal of Arthroplasty web page for relevant articles. All calculations were made using Review Manager 5.3.

RESULTS

We identified 42 studies that compared LB to an alternate analgesic modality. Seventeen of these studies were controlled trials that were included in meta-analysis. Significant differences were seen in pain scores with LB over a peripheral nerve block (mean difference = 0.45, P = .02) and LB over a traditional PAI (standard mean difference = -0.08, P = .004).

CONCLUSION

While LB may offer a statistically significant benefit over a traditional PAI, the increase in pain control may not be clinically significant and it does not appear to offer a benefit in reducing opioid consumption. However, there is no standardization among current studies, as they vary greatly in design, infiltration technique, and outcome measurement, which precludes any reliable summarization of their results. Future independent studies using a standardized protocol are needed to provide clear unbiased evidence.

Nanotechnology: A Promising New Paradigm for the Control of Pain

Objective

The objective of this article is to critically review both preclinical and clinical studies that focus on the use of nanotechnology for both acute and chronic pain management, surveying both diagnostic and therapeutic applications. The article also provides information on nanotechnology for pain practitioners, so that they may better understand how this technology works and how it may be applied to their day-to-day clinical practice.

Study Design

Narrative review.

Methods

The Pubmed NCBI and EMBASE databases were utilized to review published reports of in vivo and clinical studies that focus on using nanotechnology for pain management applications in both the acute and chronic pain settings.

Results

Articles were screened by title, abstract, and full article review. They were then analyzed by specific clinical indications, and appropriate data were presented based on a critical analysis of those articles.

Conclusions

As the development of nanomedical applications in acute and chronic pain management continues, medical practitioners should consider their growing potential to enhance the care of patients who are consistently living with pain. Current barriers to implementation include manufacturing scale-up for commercial viability, long-term nanoparticle toxicity considerations, and high cost for successful passage through clinical trials. These challenges will need to be overcome with ongoing translational research efforts in collaboration with industry and government bodies such as the Food and Drug Administration (FDA).

Periarticular Knee Injection With Liposomal Bupivacaine and Continuous Femoral Nerve Block for Postoperative Pain Management After Total Knee Arthroplasty: A Randomized Controlled Trial

BACKGROUND

Local periarticular infiltration (PAI) analgesia has emerged as an important component of multimodal approaches to treat total knee arthroplasty postoperative pain. Liposomal bupivacaine may provide prolonged analgesic duration when injected into the surrounding tissues. The purpose of this study was to compare the analgesic efficacy and serum bupivacaine levels of a continuous femoral nerve block (CFNB) with bupivacaine to PAI with liposomal bupivacaine.

METHODS

Sixty-five patients undergoing primary unilateral total knee arthroplasty were randomized into 2 groups: (1) CFNB and PAI with bupivacaine (CFNB group) or (2) PAI with bupivacaine:liposomal bupivacaine mixture at the end of surgery (LB group). The primary outcome was pain intensity at maximum knee flexion 24 hours following surgery. Secondary outcomes included pain intensities at rest and movement at timed intervals and serum bupivacaine levels.

RESULTS

Patients in the CFNB group experienced lower pain scores at maximum knee flexion at 24 hours (7.91; 95% confidence interval, 7.19-8.61) compared to the LB group (8.95; 95% confidence interval, 8.42-9.48; P = .02). The mean peak serum bupivacaine level in the LB group up to 72 hours was 0.55 μg/mL versus 1.4 μg/mL for CFNB group (P = .0008) with one patient in the CFNB group exceeding the reported minimum serum bupivacaine threshold for toxicity.

CONCLUSION

While similar pain control was observed on the day of surgery for both groups, patients with a CFNB experienced lower pain intensities during maximum knee flexion at 24 hours. Total serum concentrations in LB group remained below the toxicity threshold over the study period.

Impact of treatment with liposomal bupivacaine on hospital costs, length of stay, and discharge status in patients undergoing total knee arthroplasty at high-use institutions

Aims: Post-surgical pain experienced by patients undergoing total knee arthroplasty (TKA) can be severe. Enhanced recovery after surgery programs incorporating multimodal analgesic regimens have evolved in an attempt to improve patient care while lowering overall costs. This study examined clinical and economic outcomes in hospitals using liposomal bupivacaine (LB) for pain control following TKA.Methods: This retrospective observational study utilized hospital chargemaster data from the Premier Healthcare Database from January 2011 through April 2017 for the 10 hospitals with the highest number of primary TKA procedures using LB. Within these hospitals, patients undergoing TKA who received LB were propensity-score matched in a 1:1 ratio to a control group not receiving LB. Outcomes included hospital length of stay (LOS), discharge status, 30-day same-hospital readmissions, total hospitalization costs, and opioid consumption; only patients with Medicare or commercial insurance as the primary payer for TKA were considered.Results: The study population included 20,907 Medicare-insured patients (LB = 10,411; control =10,496) and 12,505 patients with commercial insurance (LB = 6,242; control = 6,263). Overall, LOS was 0.6 days shorter with LB (p < 0.0001), and patients who received LB were 1.6-times more likely to be discharged home (p < 0.0001). Total hospitalization costs for the TKA procedure were lower with LB for patients with both Medicare (-$616; P < 0.0001) and commercial insurance (-$775; p < 0.0001). Opioid consumption was lower with LB in both payer populations (p < 0.0001). No significant differences for 30-day readmissions were found.Limitations: Costs were estimated using Premier charge-to-cost ratios and limited to goods and services recorded in the chargemaster. Findings from these 10 hospitals may not be representative of other US hospitals.Conclusions: In a sub-set of 10 US hospitals with the highest use of LB for TKA, LB use was associated with shorter hospital LOS, increased home discharge, lower total hospitalization costs, and decreased opioid use after TKA.

Prospective Randomized Trial Comparing Femoral Nerve Block With Intraoperative Local Anesthetic Injection of Liposomal Bupivacaine in Total Knee Arthroplasty

BACKGROUND

Postoperative pain after total knee arthroplasty (TKA) may impact long-term results and incidence of complications. Femoral nerve block (FNB) provides excellent pain relief after TKA, although associated risks include weakness, delayed participation in therapy, and nerve injury. Liposomal bupivacaine (LB) is a potentially longer acting local anesthetic that may reduce postoperative pain.

METHODS

We performed a prospective, randomized, double-blind study of 373 TKA patients randomized to receive either an FNB (control group), or an intraoperative periarticular injection (PAI) with LB and a placebo saline FNB (experimental group). Patients were evaluated with visual analog scores for pain, range of motion, performance of straight leg raise (SLR), walking distance, and Short Form-12 up to 1 year postoperatively.

RESULTS

Twelve and 24 hours postoperatively, the control group had significantly lower pain scores (mean 3.24 vs 3.87; P = .02) and higher range of motion (84.54° vs 78°; P < .001). The patients receiving LB PAI were significantly more likely to perform a straight leg raise 12 hours postoperatively (73% vs 50%; P = .0003). Patients in the LB (experimental) group scored better in the physical function component of the Short Form-12 (-23 vs -27, P = .01) 3 months postoperatively.

CONCLUSION

While pain scores were slightly lower in the control group in the first 24 hours after TKA compared with LB PAI, the magnitude of the difference was small, and excellent pain relief was provided by both interventions. Use of LB PAI in TKA is a reasonable alternative to FNB, which avoids the additional weakness and other risk associated with FNB procedures.

Effect of local infiltration analgesia, peripheral nerve blocks, general and spinal anesthesia on early functional recovery and pain control in unicompartmental knee arthroplasty

Background

The aim of the study was to analyze the effect of local infiltration analgesia (LIA), peripheral nerve blocks, general and spinal anesthesia on early functional recovery and pain control in primary unicompartmental knee arthroplasty (UKA).

Methods

Between January 2016 until August 2016, 134 patients underwent primary UKA and were subdivided into four groups according to their concomitant pain and anesthetic procedure with catheter-based techniques of femoral and sciatic nerve block (group GA&FNB, n = 38) or epidural catheter (group SP&EPI, n = 20) in combination with general anesthesia or spinal anesthesia, respectively, and LIA combined with general anesthesia (group GA&LIA, n = 46) or spinal anesthesia (group SP&LIA, n = 30). Outcome parameters focused on the evaluation of pain (NRS scores), mobilization, muscle strength and range of motion up to 7 days postoperatively. The cumulative consumption of (rescue) pain medication was analyzed.

Results

The LIA groups revealed significantly lower (about 50%) mean NRS scores (at rest) compared to the catheter-based groups at the day of surgery. In the early postoperative period, the dose of hydromorphone as rescue pain medication was significantly lower (up to 68%) in patients with SP&EPI compared to all other groups. No significant differences could be detected with regard to grade of mobilization, muscle strength and range of motion. However, there seemed to be a trend towards improved mobilization and muscle strength with general anesthesia and LIA, whereof general anesthesia generally tended to ameliorate mobilization.

Conclusions

Except for a significant lower NRS score at rest in the LIA groups at day of surgery, pain relief was comparable in all groups without clinically relevant differences, while the use of opioids was significantly lower in patients with SP&EPI. A clear clinically relevant benefit for LIA in UKA cannot be stated. However, LIA offers a safe and effective treatment option comparable to the well-established conventional procedures.

Effect of local infiltration analgesia, peripheral nerve blocks, general and spinal anesthesia on early functional recovery and pain control in total knee arthroplasty

BACKGROUND

Postoperative pain control and enhanced mobilization, muscle strength and range of motion following total knee arthroplasty (TKA) are pivotal requisites to optimize rehabilitation and early recovery. The aim of the study was to analyze the effect of local infiltration analgesia (LIA), peripheral nerve blocks, general and spinal anesthesia on early functional recovery and pain control in primary total knee arthroplasty.

METHODS

Between January 2016 until August 2016, 280 patients underwent primary TKA and were subdivided into four groups according to their concomitant pain and anesthetic procedure with catheter-based techniques of femoral and sciatic nerve block (group GA&FNB, n = 81) or epidural catheter (group SP&EPI, n = 51) in combination with general anesthesia or spinal anesthesia, respectively, and LIA combined with general anesthesia (group GA&LIA, n = 86) or spinal anesthesia (group SP&LIA, n = 61). Outcome parameters focused on the evaluation of pain (NRS scores), mobilization, muscle strength and range of motion up to 7 days postoperatively. The cumulative consumption of (rescue) pain medication was analyzed.

RESULTS

Pain relief was similar in all groups, while the use of opioid medication was significantly lower (up to 58%) in combination with spinal anesthesia, especially in SP&EPI. The LIA groups, in contrast, revealed significant higher mobilization (up to 26%) and muscle strength (up to 20%) in the early postoperative period. No analgesic technique-related or surgery-related complications occurred within the first 7 days. Due to insufficient pain relief, 8.4% of the patients in the catheter-based groups and 12.2% in the LIA groups resulted in a change of the anesthetics pain management.

CONCLUSIONS

The LIA technique offers a safe and effective treatment option concerning early functional recovery and pain control in TKA. Significant advantages were shown for mobilization and muscle strength in the early postoperative period while pain relief was comparable within the groups.

Improved Chondrotoxic Profile of Liposomal Bupivacaine Compared With Standard Bupivacaine After Intra-articular Infiltration in a Porcine Model

BACKGROUND

Increasingly, liposomal bupivacaine is being used with multimodal pain management strategies. In vitro investigations have shown decreased chondrotoxicity profiles for liposomal bupivacaine; however, there is no evidence regarding its in vivo effects. Hypothesis/Purpose: This study sought to investigate the in vivo chondrotoxicity of liposomal bupivacaine, hypothesizing that there would be increased chondrocyte viability after exposure to liposomal bupivacaine when compared with standard bupivacaine.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight juvenile, female Yorkshire cross piglets underwent a lateral stifle joint injection with either 1.3% liposomal bupivacaine or 0.5% bupivacaine. Injections were performed on one joint per animal with no injection to the contralateral knee, which served as the control. Chondrocyte viability was assessed 1 week after injection with a live-dead staining protocol and histologic examination.

RESULTS

Significant chondrocyte death was seen with the live-dead staining in the bupivacaine group (33% nonviable cells) in comparison with liposomal bupivacaine (6.2%) and control (5.8%) groups ( P < .01). However, histologic examination showed no differences in chondral surface integrity, fibrillation, and chondrocyte viability.

CONCLUSION

Liposomal bupivacaine was found to be safe for intra-articular injection in this animal model. Although bupivacaine demonstrated decreased chondrocyte viability on a cellular level, histologically there were no changes. This study highlights the dichotomy between fluorescent staining and histologic appearance of articular chondrocytes in short-term analyses of viability.

CLINICAL RELEVANCE

This study supports the peri-articular application of liposomal bupivacaine in the setting of preserved articular cartilage. A single injection of standard bupivacaine did not produce histologic changes in the articular cartilage.

Liposomal Bupivacaine Versus Continuous Popliteal Sciatic Nerve Block in Total Ankle Arthroplasty

BACKGROUND

Liposomal bupivacaine (LB) is widely used in joint arthroplasty, but there is little reported on the use of LB in foot and ankle surgery. Continuous popliteal sciatic nerve block (CPSNB) is more commonly used for major foot and ankle reconstructions. The purpose of this study was to compare use of intraoperative LB injection to CPSNB as a regional anesthetic for total ankle arthroplasty (TAA), with attention to postoperative pain scores, narcotic use, and complications.

METHODS

Retrospective review of TAA patients of 2 fellowship-trained orthopedic foot and ankle surgeons was performed. Patients received either preoperative single-shot popliteal sciatic nerve block with 0.2% ropivacaine followed by intraoperative injection of LB or preoperative CPSNB alone. Outcomes examined were visual analog scale (VAS) pain score at 8 hours, 24 hours, 1 week, and 3 weeks following surgery; need for opioid pain medication refill; physician office notification for pain issues or other adverse events; and complications within the first 90 days following surgery. Standard statistical analysis was performed, and P < .05 was considered significant. Seventy-five patients were identified who underwent TAA and met inclusion criteria. Forty-one received LB, and 34 received CPSNB.

RESULTS

No statistical difference was seen between groups with regard to complications, emergency department visits, readmissions, reoperations, VAS pain score at any time point, physician office contacts, and narcotic refills. Sixteen of 41 (39%) LB patients had narcotic refills, versus 12 of 34 (35%) CPSNB patients ( P = .81). Two of 41 (5%) LB patients had a complication postoperatively, versus 4 of 34 (12%) CPSNB patients. There were no complications specific to the anesthetic used in either group.

CONCLUSION

This is the first study evaluating the use of LB for total ankle arthroplasty. Liposomal bupivacaine was safe and effective as an option for regional anesthetic and postoperative pain control, with comparable results to CPSNB.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Evaluation of analgesic regimens in total knee arthroplasty, retrospective study

OBJECTIVE:

Analgesic therapies have an immense role in early rehabilitation period after total knee arthroplasty (TKA) and multimodal approaches should be considered as the first choice of treatment. In this retrospective study, the aim was to evaluate the effectiveness of multimodal analgesic therapies for TKA, including femoral nerve block (FNB) and patient controlled analgesia (PCA).

METHODS:

The data of 79 patients who underwent TKA between January and December 2016 were retrospectively evaluated. In all, 63 patients met the inclusion criteria. Hemodynamic records and Visual Analogue Scale (VAS) pain scores for postoperative 0, 2, 4, 6, 9, and 12 hours were evaluated and patients were separated into 3 groups. Group 1: FNB with 0.25% bupivacaine, Group 2: FNB with 0.166% bupivacaine, and Group 3: No FNB.

RESULTS:

The average age of the patients was 64.3±14.9 years and average body mass index (BMI) was 32.5±5.3 kg/m². There was no statistical difference between groups in age, gender, American Society of Anesthesiologists (ASA) classification of physical health scores, BMI, or anesthesia type (p<0.05). When VAS scores at postoperative time intervals were compared, there was a statistically significant difference between Group 1 and Group 2 (p>0.05). When difference between Groups 1 and 3 and Groups 2 and 3 were compared, the difference was statistically significant for VAS 0 (p>0.05). Additional analgesic use was highest in Group 3.

CONCLUSION:

This study demonstrated that FNB significantly decreases postoperative pain intensity and additional analgesia requirement in patients undergoing TKA. A concentration of 0.166% bupivacaine is as effective as a concentration of 0.25% when used as part of a multimodal analgesia regimen in TKA.

A prospective randomized controlled trial to identify the optimal postoperative pain management in shoulder arthroplasty: liposomal bupivacaine versus continuous interscalene catheter

BACKGROUND

Shoulder arthroplasty is the fastest growing joint replacement surgery in the United States, and optimal postoperative pain management is critical to optimize outcomes for these surgeries. Liposomal bupivacaine (LB) has gained popularity for its potential to provide extended postoperative pain relief with possibly fewer side effects. The goal of this study was to assess the impact of LB compared with continuous interscalene nerve block (CISB) in terms of postoperative pain control, outpatient pain scores, and patient-reported and functional outcomes after shoulder arthroplasty surgery.

METHODS

A prospective randomized controlled clinical trial compared consecutive patients undergoing shoulder arthroplasty treated with CISB vs. LB with a single bolus interscalene block. The primary outcome measures included pain assessment up to 24 hours after surgery; in addition, all doses and times of narcotics administered during the inpatient stay were recorded. Patient-reported outcome measures for pain, satisfaction, and functional outcomes were recorded postoperatively.

RESULTS

A total of 70 of 74 consecutive patients who underwent shoulder arthroplasty were included in the study. The LB group had equivalent narcotic use, pain scores, and time to first narcotic rescue compared with the CISB group within the first 24 hours (P > .05). The LB group had higher American Shoulder and Elbow Surgeons score and Penn Shoulder Score at final follow-up. There was an increased number of complications and cost for the CISB group.

CONCLUSION

This prospective randomized controlled trial demonstrated that LB provides excellent postoperative pain relief for shoulder arthroplasty patients. In addition, LB had fewer complications and lower cost, making it a promising addition to a multimodal pain regimen for shoulder arthroplasty.

Comparison of periarticular anesthesia with liposomal bupivacaine with femoral nerve block for pain control after total knee arthroplasty: A PRISMA-compliant meta-analysis

BACKGROUND

Periarticular anesthesia (PAI) with liposomal bupivacaine (LB) and femoral nerve block (FNB) were 2 common type of pain management after total knee arthroplasty (TKA). There is no consensus about PAI with LB shows better clinical outcome than FNB. Thus, we performed a systematic review and meta-analysis to compare the efficacy and safety of PAI with LB and FNB for patients prepared for TKA.

METHODS

Randomized controlled trials (RCTs) and non-RCTs from PubMed (1966-2017.2), EMBASE (1980-2017.2), and the Cochrane Central Register of Controlled Trials (CENTRAL, 2017.2), Web of Science (1966-2017.2), and Chinese Wanfang database (1980-2017.2) were searched. Continuous outcomes including visual analogue scale (VAS) at 24, 48, and 72 hours, total morphine consumption, length of hospital, and range of motion (ROM) were reported as the weighted mean difference with 95% and confidence interval (CI) and discontinuous outcomes (the occurrence of postoperative nausea and vomiting [PONV]) were presented as relative risk with 95% CI. Random-effects model was adopted to analyze the relevant data.

RESULTS

According to the inclusion and exclusion criteria, 8 studies with 2407 patients were eligible and finally included in this meta-analysis (LB = 1114, FNB = 1293). There was no significant difference between VAS at 24, 4, and 72 hours, ROM, and the occurrence of PONV between PAI with LB group versus FNB group (P > 0.05). Compared with the FNB group, PAI with LB was associated with a significant decrease in length of hospital stay by 0.43 day (MD = -0.43; 95% CI -0.60 to -0.27; P = 0.001) and the total dose of total morphine consumption by (MD = -29.32; 95% CI -57.55 to -1.09; P = 0.042).

CONCLUSIONS

The review of trials found that PAI with LB provided a significant beneficial effect over FNB in improving the pain or decreased the total morphine consumption in patients who underwent TKA. However, PAI with LB associated with less LOS than FNB. More high quality RCTs are still needed to identify the effects and optimal dose of LB for pain management after TKA.

Role of Periarticular Liposomal Bupivacaine Infiltration in Patients Undergoing Total Knee Arthroplasty-A Meta-analysis of Comparative Trials

BACKGROUND

Over last 2 years, many trials have evaluated newly approved liposomal bupivacaine for periarticular infiltration in total knee arthroplasty (TKA) with mixed results. Our meta-analysis attempts to consolidate the results and make evidence-based conclusions.

METHODS

Trails comparing periarticular infiltration of liposomal bupivacaine to conventional analgesic regimens for total knee arthroplasty published till June 2016 were searched in medical database. Comparisons were made for length of stay (LOS), postoperative pain scores, range of motion, and opioid consumption. Meta-regression was performed for LOS to evaluate various analgesic control subgroups.

RESULTS

Sixteen trials were included in the final analysis. Liposomal bupivacaine group showed a shorter LOS (reported in 13 subgroups) than control group by 0.17 ± 0.04 days (random effects, P < .001, I² = 84.66%). Meta-regression for various types of control showed a predictability (R²) of 73%, τ² = 0.013 (random effects, P < .001, I² = 45.16). Only femoral block subgroup attained statistically significant shorter LOS on splitting the control group. Numeric pain scores were lower for pooled control group and local anesthetic infiltration subgroup in immediate postoperative phase. Second postoperative day analgesia was statistically superior to overall clubbed controls and femoral block subgroup. Superiority and/or inferiority of liposomal bupivacaine could not be proven for opioid consumption and range of motion because of a small pooled sample size. Publication bias is likely for LOS (Egger test, X intercept = 2.42, P < .001).

CONCLUSION

Liposomal bupivacaine infiltration has questionable clinical advantage, as it marginally shortens patient's hospital stay especially in comparison with patients receiving analgesic femoral nerve block. Compared with conventional regimens, it can provide slightly superior yet sustained (till second postoperative day) perioperative analgesia. High heterogeneity suggests need for standardization of infiltration techniques for better predictability of results.