Analgesia in Total Knee Arthroplasty: Current Pain Control Modalities and Outcomes

Diffusion doping of analgesics into UHMWPE for prophylactic pain management

Pain management after total joint arthroplasty is often addressed by systemic delivery of opioids. Local delivery of non-opioid analgesic drugs directly in the joint space from the UHMWPE component of the prosthesis would be highly beneficial to increase the efficacy of the drugs, decreasing the overall side effects and the risk of opioid addiction. It has been shown that effective concentrations of local analgesics can be achieved by eluting from analgesic-blended UHMWPE; however, this approach is limited by the decrease in mechanical properties resulting from the extent of phase separation of the blended drugs from the polymeric matrix. Here we hypothesized that mechanical properties could be maintained by incorporating analgesics into solid form UHMWPE by diffusion as an alternative method. Lidocaine or bupivacaine were diffused in solid form UHMWPE with or without radiation crosslinking. The loaded drug content, the spatial distribution of the drugs and their chemical stability after doping were characterized by FTIR and NMR spectroscopy, respectively. Drug release kinetics, tensile mechanical properties and wear rates were assessed. The results showed that diffusion doping could be used as a promising method to obtain a therapeutic implant material without compromising its mechanical and structural integrity.

Comparing Different Multimodal Analgesia Protocols for Primary Total Knee Arthroplasty-A Retrospective Cohort Analysis

Background: Several local regional anesthesia regimes have been described in the literature to reduce post-surgical pain following total knee arthroplasty (TKA), but it is unclear which regime has the best analgetic effect combined with the best motor function. The aim of this study was to determine if patients with infiltration between the popliteal artery and capsule of the posterior knee (IPACK) combined with an adductor canal block (SACB) had less pain, better motor function, and less opioid consumption after TKA than patients with a femoral nerve block (FNB) combined with a popliteal sciatic nerve block (PSB). Methods: In a retrospective cohort analysis, 342 patients following primary TKA were examined; 175 patients were treated with an IPACK combined with a SACB, and 167 patients with a femoral FNB combined with a PSB. The outcome parameters postoperative pain (visual analogue scale (VAS) for mobilization and at rest, functional recovery, opioid consumption, hospital discharge, and complications were analyzed and compared between both groups. Results: The IPACK/SACB group had a higher postoperative need for opioids despite higher doses of ropivacaine compared to the FNB/PSB group, accompanied by higher VAS scores. Patients' satisfaction was equal between the groups. Both groups showed comparable mobilization rates and walking distances following TKA. Conclusions: IPACK/SACB showed equal results compared to FNB/PSB for mobilization rates and patients' satisfaction following TKA without a reduction in opioid consumption.

Extended Release of Bupivacaine from Temperature-Responsive PNDJ Hydrogels Improves Postoperative Weight-Bearing in Rabbits Following Knee Surgery

Effective treatment of postoperative pain lasting for multiple days without opioids is an important clinical need. We previously reported analgesia lasting up to 96 h in a porcine soft tissue model of postoperative pain using SBG004, an extended-release formulation of bupivacaine based on the temperature-responsive polymer poly(N-isopropylacrylamide-co-dimethylbutyrolactone acrylamide-co-Jeffamine M-1000 acrylamide) [PNDJ]. Orthopaedic surgical sites such as the knee can involve complex sensory innervation which presents a distinct challenge to local anesthetic delivery. The purpose of this work was to evaluate the pharmacokinetics and efficacy of SBG004 in an orthopaedic surgical model in comparison to currently available local anesthetics. Pharmacokinetics following periarticular (PA) or intraarticular (IA) injection of SBG004 were compared against liposomal bupivacaine (Lip-Bupi) PA in New Zealand White rabbits (all doses 14.5 mg/kg). Analgesic efficacy of SBG004 (IA, PA, or IA + PA), three active comparators, and saline was evaluated following knee surgery in New Zealand White rabbits. Analgesia was assessed via weight-bearing on the operated limb during spontaneous large steps in video recordings. Systemic bupivacaine exposure lasted at least 7 days for SBG004 PA, 4 days for SBG004 IA, and 2 days for Lip-Bupi PA. In the analgesia study, weight-bearing in all active groups except SBG004 IA was more frequent versus saline through 8 h postoperatively (p < 0.05). Only SBG004 IA + PA resulted in a higher proportion of weight-bearing rabbits at 24 h versus saline (6/7 versus 2/10, p = 0.015). Analysis of pooled data from 24-72 h showed significantly greater frequency of weight-bearing in rabbits receiving SBG004 IA + PA (71%) versus saline (37%), ropivacaine cocktail (41%), and Lip-Bupi PA (36%). The results indicate that the release profile from SBG004 PA or IA coincides reasonably with the time course of postoperative pain, and SBG004 may produce longer duration of analgesia than local anesthetics currently used in knee surgery, including during the period of 24-72 h recognized as a target for extended-release local anesthetics.

Perioperative Differences Between Outpatient and Inpatient Pathways Following Hip and Knee Arthroplasty

Background

Optimization of clinical pathways and logistics led to the introduction of outpatient joint arthroplasty of the hip and knee. Nevertheless, little is known about what these current protocols look like and how they differ from "standard" inpatient protocols. This study aimed to find preoperative, intraoperative, and postoperative differences between outpatient and inpatient pathways.

Methods

A questionnaire (ranging between 23 and 37 items) was developed and administered by email to orthopedic surgeons who were a member of the Dutch Hip Society and Dutch Knee Society. Survey response rate was 38% (N = 117).

Results

No significant differences were found in preoperative pathway characteristics. The administration regime for tranexamic acid significantly differed between outpatient and inpatient pathways (P < .001 and P = .002 for hip and knee arthroplasty, respectively), with outpatient pathways using a combined (eg, oral and intravenous) administration regime more frequently. The perioperative antibiotic prophylaxis regime also significantly differed between outpatient and inpatient pathways (P < .001 and P = .014, respectively), with outpatient pathways more frequently incorporating fewer antibiotic doses. Same-day postoperative mobilization significantly less often occurred if surgery took place later that day in inpatient hip arthroplasty pathways (24%; P = .034). Postoperative hemoglobin-check occurred significantly more often on indication in outpatient than in inpatient hip and knee arthroplasty pathways (∼75% vs ∼25%; P = .001).

Conclusions

Few intraoperative and postoperative differences in outpatient and inpatient pathways were found and probably mainly relied on logistical grounds. Nonetheless, findings suggested that outpatient pathways tended to be more up-to-date and innovative than inpatient pathways.

Bibliometric and visual analysis of research on analgesia and total knee arthroplasty from 1990 to 2022

Background

In recent decades, there have been notable advancements in the field of analgesia and total knee arthroplasty (TKA). This study aims to employ bibliometric analysis to elucidate the prevailing research focal points and trends within analgesia and TKA from 1990 to 2022.

Material and methods

Relevant publications were retrieved from the Web of Science Core Collection. CiteSpace, VOSviewer, and Scimago Graphica were used for visualization and bibliometric analysis of countries, institutions, authors, journals, references, and keywords.

Results

A total of 2776 publications on analgesia and TKA were identified, with the United States having the highest number of publications. The University of Copenhagen was the most productive institution, and Kehlet, Henrik was the most prolific author. The Journal of Arthroplasty had the most publications and citations. The most common keywords were "TKA," "pain management," "postoperative pain," "Total hip arthroplasty (THA)," and "postoperative management." Keyword burst detection demonstrated that adductor canal block (ACB) was a recent research hotspot.

Conclusion

Our study revealed a sharp increase in global publications on analgesia and TKA, and this trend is expected to continue. Further research is necessary to determine the optimal regimen for multimodal analgesia, the ideal location and volume of ACB, and their clinical significance.

Chronic post-surgical pain after knee arthroplasty: a role of peripheral nerve blocks

Introduction

Peripheral nerve blocks are an efficient method of pain control after total knee arthroplasty (TKA), but there is no report of their impact on chronic post-surgical pain (CPSP).

Methods

This prospective observational study aimed to assess adductor canal block (ACB) and IPACK block (blocks vs. no blocks) on opioid consumption, postoperative pain score, chronic post-surgical pain 2 years after TKA.

Results

166 patients (82 vs. 84) were analyzed. Opioid consumption was less in the group with blocks (9.74 ± 3.87 mg vs. 30.63 ± 11.52 mg) (p < 0.001). CPSP was present in 20.24% of patients in the group without blocks and 6.1% of patients with blocks (p = 0.011). Predictor variables of CPSP included pain before surgery (cut-off of 5.5), pain at rest (cut-off of 2.35), pain during active movement (cut-off: 2.5), and opioid consumption (cut-off: 8 mg).

Conclusion

Peripheral nerve blocks provide adequate analgesia, significantly decrease opioid consumption, improve functional outcomes, and reduce CPSP 2 years after surgery.

The nuts and bolts of multimodal anaesthesia in the 21st century: a primer for clinicians

PURPOSE OF REVIEW

This review article explores the application of multimodal anaesthesia in general anaesthesia, particularly in conjunction with locoregional anaesthesia, specifically focusing on the importance of EEG monitoring. We provide an evidence-based guide for implementing multimodal anaesthesia, encompassing drug combinations, dosages, and EEG monitoring techniques, to ensure reliable intraoperative anaesthesia while minimizing adverse effects and improving patient outcomes.

RECENT FINDINGS

Opioid-free and multimodal general anaesthesia have significantly reduced opioid addiction and chronic postoperative pain. However, the evidence supporting the effectiveness of these approaches is limited. This review attempts to integrate research from broader neuroscientific fields to generate new clinical hypotheses. It discusses the correlation between high-dose intraoperative opioids and increased postoperative opioid consumption and their impact on pain indices and readmission rates. Additionally, it explores the relationship between multimodal anaesthesia and pain processing models and investigates the potential effects of nonpharmacological interventions on preoperative anxiety and postoperative pain.

SUMMARY

The integration of EEG monitoring is crucial for guiding adequate multimodal anaesthesia and preventing excessive anaesthesia dosing. Furthermore, the review investigates the impact of combining regional and opioid-sparing general anaesthesia on perioperative EEG readings and anaesthetic depth. The findings have significant implications for clinical practice in optimizing multimodal anaesthesia techniques (Supplementary Digital Content 1: Video Abstract, http://links.lww.com/COAN/A96 ).

Efficacy of a Modified Cocktail for Periarticular Local Infiltration Analgesia in Total Knee Arthroplasty: A Prospective, Double-Blinded, Randomized Controlled Trial

BACKGROUND

Periarticular local infiltration analgesia (LIA) is largely utilized for controlling pain after total knee arthroplasty (TKA). The present work aimed to assess the efficacy of a modified LIA cocktail for patients undergoing TKA.

METHODS

Magnesium sulfate (MgSO4) and sodium bicarbonate (NaHCO3) were added to a conventional LIA cocktail comprising ropivacaine, epinephrine, and dexamethasone. After the safety of this modified cocktail was tested in rats, its efficacy and safety were evaluated in a prospective, double-blinded study including 100 individuals randomized to receive periarticular infiltration of the modified cocktail or a conventional cocktail. The primary outcome was postsurgical use of morphine hydrochloride for rescue analgesia. Secondary outcomes were the time until the first rescue analgesia, postsurgical pain (on a visual analog scale [VAS]), functional recovery (assessed by range of knee motion and ambulation distance), time to discharge, and complication rates.

RESULTS

Adding NaHCO3 to the local anesthetics caused some instantaneous precipitation in all cases. Administering the modified cocktail to rats did not obviously damage the injected area of the nerve or surrounding tissues. Administration of the modified cocktail to patients was associated with markedly reduced postsurgical morphine use in the initial 24 hours (4.2 ± 5.0 versus 14.6 ± 8.9 mg, p < 0.001), reduced total morphine use (9.8 ± 8.4 versus 19.6 ± 11.4 mg, p < 0.001), prolonged time to the first rescue analgesia, lower VAS pain scores at rest and during motion at 12 and 24 hours following the operation, better functional recovery on postoperative days 1 and 2, and a shorter hospital stay. The modified and conventional cocktail groups had similar rates of complications.

CONCLUSIONS

The present modification of a conventional cocktail significantly prolonged analgesia and reduced opioid consumption, which may substantially improve pain control in arthroplasty.

LEVEL OF EVIDENCE

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

Electroacupuncture alleviates pain after total knee arthroplasty through regulating neuroplasticity: A resting-state functional magnetic resonance imaging study

INTRODUCTION

We aimed to evaluate the efficacy of electroacupuncture in relieving acute pain after total knee arthroplasty (TKA) and related mechanism.

METHODS

In this randomized, single-blind, and sham-acupuncture controlled study. Forty patients with postoperative acute pain were recruited and randomly divided electroacupuncture group (n = 20) and sham-acupuncture group (n = 20) from November 2020 to October 2021. All patients received electroacupuncture or sham-acupuncture for 5 days after TKA. Their brain regions were scanned with resting-state functional magnetic resonance imaging before and after intervention. Pain was scaled. Another 40 matched healthy controls underwent scanning once. The amplitude of low-frequency fluctuation (ALFF) values was compared. Pearson's correlation analysis was utilized to explore the correlation of ALFF with clinical variables in patients after intervention.

RESULTS

Compared with the HCs, patients with acute pain following TKA had significantly decreased ALFF value in right middle frontal gyrus, right supplementary motor area, bilateral precuneus, right calcarine fissure and surrounding cortex, and left triangular part of inferior frontal gyrus (false discovery rate corrected p < .05). Patients had higher ALFF value in bilateral precuneus, right cuneus, right angular gyrus, bilateral middle occipital gyrus, and left middle temporal gyrus after electroacupuncture (AlphaSim corrected p < .01). Correlation analysis revealed that the change (postoperative day 7 to postoperative day 3) of ALFF in bilateral precuneus were negatively correlated with the change of NRS scores (r = -0.706; p = .002; 95% CI = -0.890 to -0.323) in EA group.

CONCLUSIONS

The functional activities of related brain regions decreased in patients with acute pain after TKA. The enhancement of the functional activity of precuneus may be the neurobiological mechanism of electroacupuncture in treating pain following TKA.

Addition of infiltration between the popliteal artery and the capsule of the posterior knee (IPACK) to local infiltration analgesia for total knee arthroplasty: a prospective randomized controlled trial

BACKGROUND

Local infiltration analgesia (LIA) is a popular analgesic technique commonly administered during total knee arthroplasty (TKA). Recent studies have demonstrated that the infiltration between the popliteal artery and the capsule of the posterior knee (IPACK) can be complementary to analgesic modalities. However, the combined and relative efficacy of LIA and IPACK is unclear. We aimed to evaluate the analgesic and functional outcomes among LIA, IPACK, and LIA+IPACK.

MATERIALS AND METHODS

A total of 120 patients undergoing primary TKA were randomly allocated to 1 of 3 groups: LIA (50 mL of 0.25% ropivacaine and 2.0 μg/mL epinephrine); IPACK (20 mL of 0.25% ropivacaine and 2.0 μg/mL epinephrine); and LIA+IPACK. The primary outcome was the visual analog scale (VAS) pain score. Secondary outcomes were opioid use, knee range of motion (ROM), quadriceps muscle strength, mobilization distance, timed up and go (TUG) test, and postoperative complications.

RESULTS

The mean VAS pain scores were significantly higher after using IPACK alone than after using LIA+IPACK and LIA within 24 hours (all p＜0.05). LIA+IPACK had lower mean VAS pain scores than LIA when the knees were at rest (within 12 hours, p < 0.05) and flexion (within 8 hours, p＜0.05). Patients receiving LIA+IPACK and LIA had significantly lower morphine equivalents (ME) than those receiving IPACK alone within 24 hours (26.3, 28.9 versus 47.8, both p＜0.05) and during hospitalization (98, 101.6, versus 128.4 both p＜0.05). Both LIA+IPACK and LIA had higher ROM (within two days), higher level of muscle strength (within 12 hours), longer mobilization distances (within one day), and shorter TUG time (till discharge) compared with IPACK alone (all p＜0.05), while LIA+IPACK only had a higher knee ROM than LIA on the first postoperative day (p＜0.05). There was no significant difference in any other outcomes.

CONCLUSIONS

This randomized controlled trial demonstrated that there were significantly lower pain scores, less opioid consumption, and better functional results with LIA+IPACK and LIA when compared with IPACK alone, suggesting that IPACK alone was inferior for pain control.

Perioperative duloxetine administration reduces pain after high tibial osteotomy and non-steroidal anti-inflammatory administration: A prospective, controlled study

BACKGROUND

Postoperative pain management is essential for patient satisfaction; however, no reports have described the effect of perioperative duloxetine administration on the postoperative pain management following knee surgery. This study aimed to determine whether perioperative duloxetine administration reduces pain following high tibial osteotomy.

METHODS

In this prospective clinical trial, 35 and 33 patients receiving (40 mg/day) and not receiving duloxetine (control), respectively were enrolled. The knee pain and quality of recovery were evaluated using the numeric rating scale (NRS) scores, the frequency of analgesic drugs used, and patient-reported outcome measures, including the NRS score at rest and the Knee Injury and Osteoarthritis Outcome Score (KOOS), were compared between the groups.

RESULTS

The NRS scores of the duloxetine group (D) were significantly reduced compared with those of the control group (C) on postoperative day 1 (D:3.8 vs C:5.1, p = 0.022), day 7 (D:2.1 vs C:2.9, p = 0.021), and day 14 (D:1.6 vs C:2.9, p = 0.001). Non-steroidal anti-inflammatory drug administration was significantly lower in the duloxetine group than in the control group (p < 0.001). Although the KOOS score was not significantly different in several subcategories at the pre- and postoperative time-points, the Function in Sport subcategory of the KOOS was significantly improved in the duloxetine group compared with that in the control group at 3 months postoperatively (p < 0.05).

CONCLUSION

Perioperative use of duloxetine from 2 weeks before surgery to 2 weeks after surgery is advantageous in perioperative pain management and KOOS improvement following high tibial osteotomy.

Analgesic efficacy of adding the IPACK block to multimodal analgesia protocol for primary total knee arthroplasty: a meta-analysis of randomized controlled trials

BACKGROUND

Total knee arthroplasty (TKA) is a standard treatment for end-stage degenerative knee disease. Most patients will experience moderate-to-severe postoperative knee pain, significantly affecting rehabilitation. However, controversy remains regarding the efficacy of adding the interspace between the popliteal artery and capsule of the knee (IPACK) into multimodal analgesia protocol.

METHODS

PubMed, Medline, Embase, Cochrane Library, and other databases were searched from inception to February 1, 2021. Studies comparing patients receiving IPACK to patients not receiving IPACK were included. The primary outcome was the ambulation pain score on a visual analogue scale (VAS) of 0-10. Secondary outcomes included pain score at rest, morphine usage, functional recovery, clinical outcomes, and complications.

RESULTS

Thirteen RCTs involving 1347 knees were included. IPACK was associated with lower ambulation pain scores (weight mean difference [WMD] - 0.49, 95% confidence interval [CI] - 0.72 to - 0.26). The benefits were observed from 2 to 4 h, 6 to 12 h, and beyond one week. IPACK also significantly reduced rest pain scores (WMD - 0.49, 95% CI - 0.74 to - 0.24), and the benefits were observed from 6 to 12 h and beyond one week. IPACK reduced the overall morphine consumption (WMD - 2.56, 95% CI - 4.63 to - 0.49). Subgroup analysis found reduced oral morphine consumption from 24 to 48 h (WMD - 2.98, 95% CI - 5.71 to - 0.24) and reduced rate of morphine requirement from 12 to 24 h (relative risk [RR] = 0.51, 95% CI 0.31 to 0.83). Functional recovery outcomes regarding ambulation distances (on the second postoperative day [POD2]) (WMD = 1.74, 95% CI 0.34 to 3.15) and quadriceps muscle strength (at 0 degree) (WMD = 0.41, 95% CI 0.04 to 0.77) favored IPACK. And IPACK reduced the rate of sleep disturbance (on POD 1) (RR = 0.39, 95% CI 0.19 to 0.81). There was no significant difference in the other outcomes.

CONCLUSIONS

Moderate-level evidence confirmed that IPACK was related to better results in pain scores, morphine usage, and functional recovery without increasing the risk of complications.

REGISTRATION

CRD42021252156.

The efficacy of parecoxib in improving pain after total knee or total hip arthroplasty: Systematic review and meta-analysis

BACKGROUND

The cyclooxygenase-2 (COX-2) selective inhibitor parecoxib is widely used in the treatment of pain and inflammation. Parecoxib has been adopted for use for postoperative analgesia following a range of surgical procedures (orthopedic, general, gynecological, and dental surgery). Total knee or total hip arthroplasty (THA) surgery is mostly done in older patients, so postoperative analgesics need to be used more carefully, and the safety and efficacy of parecoxib in this type of surgery need to be further verified. The aim of this study was to investigate the effects of parecoxib on patient safety, cumulative morphine consumption and was at 24 and 48 hours in the analgesic treatment of total knee or THA for meta-analysis and systematic review, with few studies in this area so far.

METHODS

We searched the Online Database Cochrane Library, PubMed, Web of Science, EMBASE, and CBM (SinoMed), CNKI, VIP, WANFANG up to January 2021. According to the value of I2, the random-effect model or fixed-effect model was supposed to combine data from studies, respectively. Publication bias was assessed through funneling plot and Beggs test. Review Manager 5.3 and Stata 16.0 software were applied to perform the statistical analyses.

RESULTS

Eleven RCTs which involved 1690 participants were included in this study. The meta-analysis indicated parecoxib sodium could not significantly reduce the incidence of adverse events after total knee or THA compared with placebo. There was no statistical significance in incidence of nausea and vomiting. 24 hours resting VAS score was statistically significant between the group. The 48-hour resting VAS scores did not indicate a significant difference between the groups.

CONCLUSION

Parecoxib can reduce the incidence of adverse events after total knee or total hip surgery to some extent but cannot reduce the incidence of nausea and vomiting. Twenty-four hour postoperative analgesia is better than placebo, but 48 hours after operation analgesia is the same as placebo.

IPACK (Interspace between the Popliteal Artery and the Capsule of the Posterior Knee) Block Combined with SACB (Single Adductor Canal Block) Versus SACB for Analgesia after Total Knee Arthroplasty

OBJECTIVES

To evaluate the combination of the infiltration between the popliteal artery and the posterior capsule of the knee (iPACK) block and single adductor canal block (SACB) versus SACB for motor-sparing knee analgesia effects after total knee arthroplasty (TKA).

METHODS

PubMed, Ovid, Cochrane Library, and other databases were searched from the inception to January 2021. Randomized controlled trials (RCTs) comparing patients receiving iPACK plus SACB with patients receiving SACB after TKA were included. The included studies were assessed by two reviewers according to the Cochrane risk of bias criteria. Meta-analysis was performed with STATA 13.0 software, the risk ratios (RR) and mean differences (MD) were used to compare dichotomous and continuous variables. The primary outcome was ambulation pain and secondary outcomes were rest pain, opioid consumption, function ability, clinical outcomes, and complications.

RESULTS

Seven RCTs (304 knees in iPACK + SACB group; 305 knees in SACB group) were included. The follow-up periods ranged from 2 days to 3 months. Pooled data indicated lower pain scores at ambulation (p < 0.0001) for iPACK + SACB. When comparing the pain scores of subgroups analyzed at specific periods, lower scores in subgroups within 12 h (at rest and ambulation) and after 48 h (at ambulation) were observed in the iPACK + SACB group. Analysis demonstrated greater reduction in morphine consumption (p = 0.007) in the iPACK + SACB group. The iPACK + SACB group is also superior to the SACB group regarding function ability, which included range of motion (ROM) (p = 0.001), time up to go (TUG) test (p = 0.030), and ambulation distance (p < 0.0001). No difference was found in clinical outcomes or complications.

CONCLUSIONS

With the iPACK added to SACB, pain scores, morphine consumption, functional ability were improved. Additional high-quality studies are required to further address this topic.

Comparison Between Periarticular Analgesia Versus Intraarticular Injection for Effectiveness and Safety After Total Knee Arthroplasty

PURPOSE

In most studies, local infiltration analgesia (LIA) can provide better analgesic effect in the early postoperative period, but the optimal technique is unknown. Our study was designed to evaluated the early clinical efficacy and safety of periarticular analgesia versus intraarticular injection in Total knee arthroplasty (TKA).

DESIGN

A prospective study was conducted on 100 patients admitted for TKA. Subjects were divided into two groups: 50 in group A, 50 in Group B.

METHODS

Patients in group A received periarticular analgesia with ropivacaine 300 mg and morphine 5 mg (the drugs were diluted with saline to 50 ml) in the periosteal borders, posterior capsule and extensor apparatus and subcutaneous tissues during surgery. After stitching of joint capsule, tranexamic acid (TXA) 2 g (20 ml) was injected into the articular cavity. Group B patients had all of the 70 mL mixture (ropivacaine 300 mg, morphine 5 mg and TXA 2 g) injected intraarticularly after stitching of the joint capsule. We assessed postoperative length of stay (LOS), knee functional outcome, pain, and complications after surgery.

FINDINGS

There was no statistical difference in visual analog scale (VAS) scores for knee pain between the two groups on postoperative day (POD)1, 3, or 30 (P > .05). Mean postoperative LOS was 7.40 ± 1.98 days in Group A, compared to 8.02 ± 2.09 days in Group B (P > .05). No significant differences between groups were seen in the mean swelling ratio (P > .05), and no significant differences were found in the Hospital for Special Surgery (HSS) knee score and range of motion (ROM) at 30 days follow-up (P > .05). There was also no statistical difference in the incidence of complications (such as superficial wound infection, deep vein thrombosis (DVT) and nausea and vomiting) between the Group A and the Group B.

CONCLUSIONS

In conclusion, it seems that intraarticular injection had a similar analgesic effect compared with periarticular injection when adopting a multi-modal analgesia regimen. Our results suggest that there is no obvious advantage with the use of periarticular injections compared to intraarticular injection. The authors believe that intraarticular injection may be a better technique compared with periarticular injections in the absence of a drainage tube because intraarticular injection can reduce the number of surgical steps and have similar postoperative outcomes.

Cryoneurolysis Is a Safe, Effective Modality to Improve Rehabilitation after Total Knee Arthroplasty

Although long term pain and mobility outcomes in total knee arthroplasties (TKA) are successful, many patients experience significant amount of debilitating pain during the immediate post-operative period that necessitates narcotic use. Percutaneous cryoneurolysis to the infrapatellar saphenous and anterior femoral cutaneous nerves may help to better restore function and rehabilitation after surgery while limiting narcotic consumption. A retrospective chart review of primary TKA patients receiving pre-operative cryoneurolysis from 2019 to 2020 was performed to assess total opioid morphine milligram equivalents (MME) consumed inpatient and at interval follow-up. Demographics and medical comorbidities were compared between cryoneurolysis and age-matched control patients to assess baseline characteristics. Functional rehabilitation outcomes, including knee range of motion (ROM), ambulation distance, and Boston AM-PAC scores, as well as patient reported outcomes using the KOOS JR and SF-12 scores were analyzed using STATA 17 Software. The analysis included 29 cryoneurolysis and 28 age-matched control TKA patients. Baseline demographics and operative technique were not significant between groups. Although not statistically significant, cryoneurolysis patients had a shorter length of stay (2.5 vs. 3.5 days) and overall less inpatient and outpatient MME requirements. Cryoneurolysis patients had statistically significant improved 6-week ROM and 1-year follow-up KOOS JR and SF-12 mental scores compared to the control. There were no differences in complication rates. Cryoneurolysis is a safe, effective treatment modality to improve active functional recovery and patient satisfaction after TKA by reducing MME requirements. Patients who underwent cryoneurolysis had on average fewer MME prescribed during the perioperative period, improved active ROM, and improved patient-reported outcomes with no associated increased risk of infections, deep vein thrombosis, or neurologic complications.

Review on Nerve Blocks Utilized for Perioperative Total Knee Arthroplasty Analgesia

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

Liposomal Bupivacaine in Adductor Canal Blocks Before Total Knee Arthroplasty Leads to Improved Postoperative Outcomes: A Randomized Controlled Trial

BACKGROUND

This study compares the use of liposomal bupivacaine (Exparel) versus ropivacaine in adductor canal blocks (ACB) before total knee arthroplasties (TKAs).

METHODS

From the months of April 2020 to September 2021, 147 patients undergoing unilateral primary TKA were asked to participate in this prospective, double-blinded randomized controlled trial. Each patient received an iPACK block utilizing ropivacaine and was additionally randomized to receive an ACB with Exparel or Ropivacaine. For each patient, demographic information, inpatient hospital information, postoperative opioid use, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire scores were collected.

RESULTS

Overall, 100 patients were included (50 in each cohort). The Exparel group had a lower hospital length of stay compared to the Control group (36.3 vs 49.7 hours, P < .01). Patients in the Exparel group reported an increased amount of Numerical Rating Scale pain score improvement at all postoperative timepoints. These patients also used a lower amount of inpatient opioids (40.9 vs 47.3 MME/d, P = .04) but a similar amount of outpatient opioids (33.4 vs 32.1 MME/d, P = .351). Finally, the Exparel group had increased improvements in all WOMAC subscores and total scores at most timepoints compared to the Control group (P < .05).

CONCLUSION

Exparel peripheral regional nerve blocks lead to decreases in pain levels, shorter hospital lengths of stay, inpatient opioid usage, and improved WOMAC scores. Exparel can be safely used in ACB blocks before TKA to help in controlling postoperative pain and decrease length of stay.

Earlier Initiation of Postoperative Physical Therapy Decreases Opioid Use after Total Knee Arthroplasty

For patients with advanced osteoarthritis of the knee, total knee arthroplasty (TKA) has been shown to provide significant pain relief and improved function with consistent, reproducible results. Post-operative physical therapy (PT) plays an important role is restoring muscle strength and range of motion (ROM). Yet, the impact of earlier physical therapy initiation after TKA has not been well defined. We assessed 205 patients that underwent primary TKA including 136 patients who started PT on the first post-operative day (POD1) and a second group that started PT 3 days after surgery (POD3), or later. Length of hospital stay (LOS), opioid use during hospital stay, complications, re-admissions, knee ROM and the need for subsequent hospitalized rehabilitation were recorded. LOS was not significantly shorter in the early PT group, compared with the delayed PT group (6.4 ± 2.2 days vs. 6.8 ± 2 days, respectively, P = .217). Patients in the delayed PT group consumed more opioids during their inpatient stay compared with the early PT group on both POD 3 (89% vs 82%, p = 0.013) and POD 4 (81% vs 66%, p = 0.005). There was no significant difference in the incidence of Immediate post-operative complications or final knee ROM between the two groups. While early postoperative PT did not impact hospital LOS or final knee ROM, it was associated with an earlier reduction in postoperative opioid consumption after primary TKA.

Does Nefopam Provide Analgesic Effect and Reduce Morphine Consumption After Primary Total Knee Arthroplasty? A Prospective, Double-Blind, Randomized Controlled Trial

BACKGROUND

One of the most undesirable results after total knee arthroplasty (TKA) is severe immediate postoperative pain, resulting in patient dissatisfaction. We aimed to evaluate nefopam's analgesic efficacy after primary TKA along with related outcomes, including morphine consumption and adverse events.

METHODS

We conducted a double-blind, randomized controlled trial of patients undergoing unilateral primary TKA, comparing 24 hours of 80 mg of continuous intravenous nefopam to placebo infusion. A 100-mm Visual Analog Scale (VAS) for pain-at-rest and in-motion ≤48 hours was the primary outcome measure. Secondary outcomes were morphine and antiemetic consumption, adverse events, and functional outcomes: time-to-walk, timed up-and-go test, postoperative knee range of motion at 24 and 48 hours, time-to-discharge, and patient satisfaction scores.

RESULTS

Patients in the nefopam group had significantly lower VAS at rest 6 hours postop (20.3 ± 27.3 vs 35 ± 24.3, P = .01). Other timepoints and in-motion VAS did not significantly differ. Total morphine consumption (0-48 hours) was 37% less, significantly lower, in the nefopam group (5.3 ± 4.5 vs 8.4 ± 7.5 mg, P = .03). Antiemetic consumption was also 61% lower in the nefopam group but not statistically significant (0.8 ± 2.3 vs 2.0 ± 3.8 mg, P = .08). There were no variations in adverse events, functional outcomes, and satisfaction scores between groups.

CONCLUSION

Continuous nefopam administration as part of multimodal analgesia for 24 hours post-TKA produced a significant analgesic effect but only within the first 6 hours. However, there was a notable reduction in morphine use 48 hours postop. Nefopam is a useful agent for contemporary pain control after TKA.

LEVEL OF EVIDENCE

Therapeutic Level I.

Intraoperative Acupuncture as Part of a Multimodal Analgesic Regimen to Reduce Opioid Usage After Total Knee Arthroplasty: A Prospective Cohort Trial

Objective: Given the U.S. opioid crisis, surgeons and anesthesiologists must collaborate to optimize nonopioid analgesics perioperatively. A common surgical procedure, total knee arthroplasty (TKA) is a critical target for opioid reduction and development of enhanced recovery protocols. Auricular therapy can help reduce pain and opioid analgesic use in the perioperative timeperiod, but intraoperative use for TKA has yet to be explored. The aim of the present study was to investigate the effect of integrating intraoperative auricular therapy as part of an opioid-sparing protocol for TKA. Materials and Methods: In this prospective cohort study, 41 patients undergoing primary unilateral TKA under neuraxial anesthesia received a standardized, opioid-free intraoperative protocol including electroauricular acupuncture. The primary outcome was the number of patients able to remain on a low-dose opioid regimen: ≤112.5 oral morphine equivalents. Additional outcomes included patient-reported pain scores, side-effects, and prior experience with acupuncture. Results: Of the 40 patients who completed the study, 26 (65%) maintained a low-dose opioid regimen, with 3 (7%) remaining opioid-free for 30 days. No subjects used opioids beyond 30 days. Mean pain scores were low at rest (Day 0: 3.4, standard deviation [SD] 2.4; Day 1: 2.4, SD 1.8) and moderate with movement (Day 0: 4.8, SD 2.6; Day 1: 5.1, SD 2.1). The most-common side-effects were dry mouth (43.2%), drowsiness (24.3%), and lightheadedness (24.3%). Conclusions: Incorporating intraoperative electroauricular acupuncture into an existing multimodal analgesia regimen is a feasible way to maintain a low-dose opioid regimen after TKA. This research was registered at clinicaltrials.gov as Clinical Trial Number: NCT#04084288.

The Efficacy and Safety of Glucocorticoid on Periarticular Infiltration Analgesia in Total Knee Arthroplasty: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

The objective of this systematic review and meta-analysis was to examine the effect and safety of multimodal cocktail protocols implemented with or without glucocorticoids on periarticular infiltration analgesia (PIA) in patients undergoing total knee arthroplasty (TKA).

METHODS

We comprehensively searched the PubMed, Medline, Embase, and Cochrane Library databases up to November 2020 for randomized controlled trials on glucocorticoids as a component of the cocktail protocol used in PIA for patients with TKA.

RESULTS

Our meta-analysis included 11 randomized controlled trial studies with 1051 primary TKAs (930 patients). Visual analog scale scores at postoperative day (POD) 1 and POD 2 in the glucocorticoid groups were significantly lower than those in the control group (95% CI [-1.01--0.10], P = .02; 95% CI [-0.51--0.13], P = .001). Furthermore, the glucocorticoid group was associated with a statistically significant improvement in the range of motion at POD 1 (95% CI [3.20-8.05] P < .00001), reduction in total morphine consumption at 24 hours, and lower levels of C-reactive protein on POD 2/3 compared with the control group. However, neither the length of hospital stays nor the long-term Knee Society Knee Score showed any differences between the two groups. In addition, the results of subgroup analyses favored triamcinolone acetonide over betamethasone, methylprednisolone, and dexamethasone regarding the postoperative visual analog scale scores and range of motion.

CONCLUSION

Glucocorticoid supplementation in PIA is effective and does not increase complications or side effects for patients with either unilateral or bilateral TKA. Moreover, triamcinolone acetonide could be recommended in multimodal cocktail protocols for glucocorticoid supplementation.

Comparative evaluation of analgesic efficacy of buprenorphine transdermal patch and fentanyl patch in management of postoperative pain after arthroscopic lower limb surgery: A randomized controlled trial

Background and Aims

Transdermal opioids are newer modality in use for the control of postoperative pain, because of its noninvasiveness, longer duration of action, sustained blood levels, and with minimal side effects. The study was aimed to evaluate the efficacy of analgesia of buprenorphine patch 10, 20 μg·h^-1 and fentanyl patch 25 μg·h^-1 for relief of pain in the postoperative period in patients undergoing arthroscopic lower limb surgeries.

Materials and Methods

It was a randomized, double-blinded, prospective study in which adult patients undergoing lower limb arthroscopic surgery were randomly segregated into three groups. In Group 1 (fentanyl patch 25 μg·h^-1), Group 2 (buprenorphine patch 10 μg·h^-1), and Group 3 (buprenorphine patch 20 μg·h^-1), transdermal patches were applied 12 h prior to surgery. Mean NRS score, total rescue analgesic requirement, drug-related adverse effects, and hemodynamic status were evaluated till 72 h in the postoperative period.

Results

Out of 175 screened patients, 150 patients were finally analyzed. Baseline characteristics were the same among all the three groups. Median NRS score was lowest in Group 3 [P value < 0.05 at 2, 4, 8, 12, and 24 h after surgery (Kruskal Wallis test). The total consumption of postoperative rescue analgesic diclofenac was the lowest in Group 3 as compared to other groups without any significant increase in adverse events.

Conclusions

In arthroscopic lower limb surgery, buprenorphine patch (20 μg·h^-1) applied 12 h prior to surgery is an effective postoperative analgesic and it is not associated with any significant adverse effects.

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.

Adductor Canal Block Combined With iPACK (Interspace Between the Popliteal Artery and the Capsule of the Posterior Knee) Block vs Periarticular Injection for Analgesia After Total Knee Arthroplasty: A Randomized Noninferiority Trial

BACKGROUND

The combination of adductor canal block (ACB) and infiltration between the popliteal artery and the posterior capsule of the knee (iPACK) block may provide sufficient motor-sparing anterior and posterior knee analgesia after total knee arthroplasty. This study aimed to determine if ACB with iPACK block was noninferior to ACB with periarticular injection (PAI) when combined with postoperative multimodal analgesia regimen.

METHODS

Seventy-six patients were randomized to receive either ACB + iPACK block and continuous ACB (CACB) (ACB + iPACK group) or PAI and CACB (ACB + PAI group). Noninferiority was concluded for the primary outcome if the adjusted mean between-group difference in pain on movement at 12 postoperative hours was within 1.3 points on a visual analog pain scale. Pain scores, morphine consumption, functional performance, and adverse events were the secondary outcome measures assessed for superiority.

RESULTS

Adjusted mean differences, (ACB + iPACK) - (ACB + PAI), in anterior and posterior knee pain scores on movement at 12 postoperative hours were -0.66 (-1.86, 0.54) and -0.19 (-1.36, 0.99), respectively. The upper limit of 95% confident interval was lower than the prespecified noninferiority limit. The mean visual analog scale pain scores were low and no clinically significant differences between groups. However, morphine requirement at 48 postoperative hours was significantly higher (P < .05) and showed greater reduced quadriceps strength at 0 and 45 degrees on postoperative day 0 (P = .006 and .04, respectively) in the ACB + iPACK group.

CONCLUSIONS

ACB with iPACK block provides a noninferior analgesia compared with PAI when combined with CACB. However, patients who received ACB + iPACK block may require higher amounts of opioids and have worse immediate functional performance.

LEVEL OF EVIDENCE

Therapeutic level I.