A Cadaveric Study of Ultrasound-Guided Subpectineal Injectate Spread Around the Obturator Nerve and Its Hip Articular Branches:

Subpectineal obturator nerve block reduces opioid consumption after hip arthroscopy: a triple-blind, randomized, placebo-controlled trial

BACKGROUND

Hip arthroscopy causes severe pain during the first few hours in the postoperative care unit. This is probably due to the intraoperative stretching of the hip joint capsule. Pain relief requires high doses of opioids which may prolong recovery and may cause opioid-related adverse events.The majority of hip joint capsule nociceptors are located anteriorly. The obturator nerve innervates the anteromedial part of the hip joint capsule. We hypothesized that a subpectineal obturator nerve block using 15 ml bupivacaine 5 mg/mL with added epinephrine 5 μg/mL would reduce the opioid consumption after hip arthroscopy.

METHODS

40 ambulatory hip arthroscopy patients were enrolled in this randomized, triple-blind controlled trial. All patients were allocated to a preoperative active or placebo subpectineal obturator nerve block. The primary outcome was opioid consumption for the first 3 hours in the postanesthesia care unit. Secondary outcomes were pain, nausea, and hip adductor strength.

RESULTS

34 patients were analyzed for the primary outcome. The mean intravenous morphine equivalent consumption in the subpectineal obturator nerve block group was 11.9 mg vs 19.7 mg in the placebo group (p<0.001). The hip adductor strength was significantly reduced in the active group. No other intergroup differences were observed regarding the secondary outcomes.

CONCLUSION

We found a significant reduction in the opioid consumption for patients receiving an active subpectineal obturator nerve block. The postoperative intravenous morphine equivalent reduction the first painful 3 hours was reduced by 40% for patients receiving a subpectineal obturator nerve block in this randomized, triple-blind trial.

TRIAL REGISTRATION NUMBER

EudraCT database 2021-006575-42.

Comparison of the Analgesic Effect of Pericapsular Nerve Group Block and Lumbar Erector Spinae Plane Block in Elective Hip Surgery

Background and Objectives: The aim of this study was to compare the effectiveness of pericapsular nerve group (PENG) and lumbar erector spinae plane (L-ESP) blocks, both administered with a high volume (40 mL) of local anesthetic (LA), for multimodal postoperative analgesia in patients undergoing hip surgery. Materials and Methods: This was a prospective, double-blind, randomized study that included 75 adult patients who were divided into three equal groups: control, PENG, and L-ESP. The study compared pain intensity, morphine consumption, time to first morphine request, and postoperative satisfaction between the control group, which received standard multimodal analgesia, and the block groups, which received PENG or L-ESP block in addition to multimodal analgesia. The numerical rating scale (NRS) was used to measure pain intensity. Results: The results showed that the block groups had lower pain intensity scores and morphine consumption, a longer time to the first morphine request, and higher postoperative satisfaction compared to the control group. The median maximum NRS score during the first 12 h was four in the control group, two in the PENG group, and three in the L-ESP group. The control group (21.52 ± 9.63 mg) consumed more morphine than the two block groups (PENG, 11.20 ± 7.55 mg; L-ESP, 12.88 ± 8.87 mg) and requested morphine 6.8 h earlier and 5 h earlier than the PENG and L-ESP groups, respectively. The control group (median 3) had the lowest Likert satisfaction scores, while the PENG group (median 4) had the lowest NRS scores (L-ESP, median 4). Conclusions: The application of PENG or L-ESP blocks with high-volume LA in patients undergoing hip surgery reduces the need for postoperative analgesia and improves the quality of multimodal analgesia.

Ultrasound-guided pericapsular nerve group and obturator nerve phenol neurolysis for refractory inpatient hip cancer metastasis pain: a case report

INTRODUCTION

Bone cancer metastasis may produce severe and refractory pain. It is often difficult to manage with systemic analgesics. Chemical neurolysis may be an effective alternative in terminally ill patients.

CASE REPORT

Female terminally ill patient with hip metastasis of gastric cancer in severe pain. Neurolytic ultrasound-guided blocks of the pericapsular nerve group and obturator nerve were performed with 5% phenol. This led to satisfactory pain relief for 10 days, until the patient's death.

DISCUSSION

This approach may be effective and safe as an analgesic option for refractory hip pain due to metastasis or pathologic fracture in terminally ill patients.

Sonographic Obturator Nerve Block At Level Of Superior Pubic Ramus: A Thiel based Cadaveric Investigation With Latex

INTRODUCTION

A proximal obturator nerve block has a similar block efficacy as the distal obturator nerve block. Previous cadaveric investigation injecting methylene blue dye solution and an immediate dissection proved the solution engulfing the anterior and posterior divisions of the obturator nerve as they emerge from the obturator canal. Uptake of methylene blue dye by the fascia and muscles obscures the exact delineation of the stained nerves. We hypothesized that injection of latex at the level of superior pubic rami in the plane between pectineus and obturator externus under real time ultrasound and a delayed dissection in a Thiel-based cadaver would be the optimal cadaveric investigational technique.

METHODS

Three investigated bodies donated to science (BDTS) fall under the strict rules of the donation program of the Department of Macroscopic and Clinical Anatomy of the Medical University of Graz and the Styrian burial law. The BDTS were embalmed with Thiel´s method which provides very lifelike conditions for investigations with regional anaesthesia backgrounds. In two cadavers (a total of specimens), latex injections were performed under ultrasound, while in the third cadaver cross-sections were executed.

RESULTS

Our Thiel based cadaveric open dissection (C1 and C2) demonstrated that a single injection of latex in the inter-fascial plane between the pectineus muscle and the obturator externus muscle at the level of superior pubic ramus led to adequate spread along trunk of the obturator nerve and its branches in all specimens.

CONCLUSIONS

An in-plane ultrasound-guided latex injections at the level of superior pubic rami, between the pectineus and the obturator externus muscles soaks the anterior ramus, posterior ramus, and the obturator nerve trunk.

Anatomical and Radiological Assessments of Injectate Spread Stratified by the Volume of the Pericapsular Nerve Group Block

BACKGROUND

The pericapsular nerve group (PENG) block was recently suggested as a regional technique for managing acute pain after hip surgery. However, few anatomical studies have confirmed the spread of injectate during the PENG block. This cadaver study aimed to analyze injectate spread to the target nerves during single-injection ultrasound-guided PENG block.

METHODS

Ultrasound-guided PENG block with 3 different injectate volumes (10, 20, or 30 mL) was performed in 18 cadavers. Injectate spread by the volume was first evaluated on computed tomography, followed by cadaver dissection. The spread of the dye over the pelvis and lower limb was evaluated.

RESULTS

The articular branches of the femoral nerve were stained nearly sufficiently with 20- and 30-mL specimens. The femoral nerve itself was stained simultaneously in six of 12 (50%) 20-mL specimens and 12 of 12 (100%) 30-mL specimens. The accessory obturator nerve was observed only in three (9%) of 36 specimens. The articular branches of the obturator nerve were rarely affected, regardless of injectate volume (1/12, 10 mL specimens; 2/12, 20 mL specimens; 1/12, 30 mL specimens; P > .999). Rather, the obturator nerve was affected. However, the obturator nerve was not stained consistently even with 30 mL of injectate (50%).

CONCLUSIONS

After combining the dissection and radiological findings, the single-injection ultrasound-guided PENG blocks with volumes of 10, 20, and 30 mL do not support motor sparing or selective anterior hip capsule innervation in a clinical setting. If early rehabilitation is needed, high-volume PENG block might not be the ideal option, and persisting pain after PENG block might be attributed in part to the lack of obturator nerve articular branches blockade.

Efficacy of pericapsular nerve group block vs. fascia iliaca compartment block for Hip surgeries: A systematic review and meta-analysis

Objective

The review aimed to compare outcomes of pericapsular nerve group block (PENG) vs. fascia iliaca compartment block (FICB) for patients undergoing hip surgeries.

Methods

Randomized controlled trials (RCTs) published in the databases of PubMed, CENTRAL, Embase, and Web of Science comparing PENG vs. FICB for pain control after hip surgeries were included in the review.

Results

Six RCTs were included. 133 patients received PENG block and were compared with 125 patients receiving FICB. Our analysis showed no difference in 6 h (MD: -0.19 95% CI: -1.18, 0.79 I 2 = 97% p = 0.70), 12 h (MD: 0.04 95% CI: -0.44, 0.52 I 2 = 72% p = 0.88) and 24 h (MD: 0.09 95% CI: -1.03, 1.21 I 2 = 97% p = 0.87) pain scores between PENG and FICB groups. Pooled analysis showed that mean opioid consumption in morphine equivalents was significantly less with PENG as compared to FICB (MD: -8.63 95% CI: -14.45, -2.82 I 2 = 84% p = 0.004). Meta-analysis of three RCTs showed no variation in the risk of postoperative nausea and vomiting in the two groups. The quality of evidence on GRADE was mostly moderate.

Conclusion

Moderate quality of evidence suggests that PENG may result in better analgesia than FICB in patients undergoing hip surgeries. Data on motor-sparing ability and complications are scarce to draw conclusions. Further large-scale and high-quality RCTs should be conducted to supplement current findings.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022350342.

Pericapsular nervegroup (PENG) block—a scoping review

The obturator nerve and its accessory branch supplying the hip region, unlike the femoral nerve, are not adequately anaesthetized by conventional regional anaesthetic techniques targeting the hip region. With advancements in ultrasound-guided regional anaesthetic techniques, interests are revived in the field and efforts are being made to block them together. One such successful attempt is the novel peri-capsular nerve group (PENG) block. Consequently, further research on the PENG block began to explore its versatilities. The present study undertakes a scoping review of research on the PENG block in humans for any indication to determine the extent of the research done, the methodologies used, and other practical issues addressed in the research. This will help to identify potential research gaps that should be addressed in the future. PubMed, Google Scholar, Cochrane Library, KoreaMed, Latin American and Caribbean Health Science Literature, and the directory of open access journals were searched with the keyword “PENG block” and “pericapsular nerve group”. Manual search of electronically retrieved papers was also carried out. Among the 67 articles selected in our review, eighteen are case series; twenty-nine are case reports; two are randomized studies; one each of prospective cohort study, review, and cadaveric study; and 15 are editorials. However, only 64 articles were included later due to the retraction of three case reports. Data is insufficient to provide firm recommendations for or against different aspects of the block. The review encourages future work addressing different aspects of the PENG block.

Pericapsular Nerve Group Block and Iliopsoas Plane Block: A Scoping Review of Quadriceps Weakness after Two Proclaimed Motor-Sparing Hip Blocks

Iliopsoas plane (IP) is a fascial plane deep to the iliopsoas complex that can serve as a potential space for the injection of local anesthetics to selectively block the articular branches of femoral nerve and accessory obturator nerve to the anterior hip capsule. Two highly similar ultrasound-guided interfascial plane blocks that target the IP, pericapsular nerve group (PENG) block and iliopsoas plane block (IPB), were both designed to achieve motor-sparing sensory block to the anterior hip capsule. However, the most recent evidence shows that PENG block can cause 25% or more of quadriceps weakness, while IPB remains the hip block that can preserve quadriceps strength. In this scoping review of quadriceps weakness after PENG block and IPB, we first performed a focused review on the complicated anatomy surrounding the anterior hip capsule. Then, we systematically searched for all currently available cadaveric and clinical studies utilizing PENG block and IPB, with a focus on quadriceps weakness and its potential mechanism from the perspectives of fascial plane spread along and outside of the IP. We conclude that quadriceps weakness after PENG block, which places its needle tip directly deep to iliopsoas tendon (IT), may be the result of iliopectineal bursal injection. The incidental bursal injection, which can be observed on ultrasound as a medial fascial plane spread, can cause bursal rupture/puncture and an anteromedial extra-IP spread to involve the femoral nerve proper within fascia iliaca compartment (FIC). In comparison, IPB places its needle tip lateral to IT and injects just one-fourth of the volume of PENG block. The current evidence, albeit still limited, supports IPB as the true motor-sparing hip block. To avoid quadriceps weakness after PENG block, a more laterally placed needle tip, away from the undersurface of IT, and a reduction in injection volume should be considered. Future studies should focus on comparing the analgesic effects and quadriceps function impairment between PENG block and IPB.

A Preliminary Analysis of a Modified Anterior Approach to Hip Pericapsular Neurolysis for Inoperable Hip Fracture Using the IDEAL Framework

Introduction: With an increasingly ageing population, there is a growing impact of fragility hip fracture on the healthcare system and on society as a whole. Oral and injectable analgesics are often insufficient whilst traction and regional blocks do not allow patients to be discharged easily. While the conventional approach of ultrasound-guided anterior hip pericapsular neurolysis can help a lot of inoperable hip fracture patients to relieve their fracture pain and facilitate subsequent nursing care, enormous technical challenges are encountered in some cases. In this retrospective case study, we evaluated the overall pain and functional outcomes of our modified approach of anterior hip pericapsular neurolysis for inoperable hip fractures using the IDEAL framework. Method: This retrospective case series studied patients with acute inoperable hip fracture who received the modified approach of anterior hip pericapsular neurolysis from January 2018 to June 2019 according to the IDEAL recommendations. The modified approach consisted of pericapsular nerve group (PENG) injection, iliopsoas plane infiltration, and the sagittal approach of obturator nerve articular branches (ONAB) injection. Subsequent alcohol neurolysis would be performed in the same setting if there were positive diagnostic blocks. Assessments were carried out on post-intervention day 5. The primary outcome was pain intensity during hip flexion at 80 degrees in the recumbent position and during gentle hip internal and external rotation using an appropriate pain scoring tool. The secondary outcomes were the range of tolerable hip flexion and occurrence of any lower limb neurological deficit because of the procedure. Interim outcomes were also briefly evaluated. Results: Among the 74 patients who were reviewed in the study period, the median dynamic pain at hip flexion 80° (p < 0.001) and on gentle hip external and internal rotation (p < 0.001) was significantly reduced from a composite score of 3 (severe pain) to 1 (mild pain) on post-intervention day 5 after the modified approach of hip neurolysis. This translated to 72% of patients achieving satisfactory pain control, which was defined as a composite pain score of ≤1 on hip flexion at 80°. Functionally, the mean range of tolerable hip flexion significantly improved from 39.7° at baseline to 74° on post-intervention day 5 (p < 0.001). Transient and reversible hypotension was seen in about 10% of the patients. No other major procedural adverse event was noted. Interim follow-up at 4−6 months post-intervention revealed that more than 95% of patients continued to have satisfactory dynamic pain control (i.e., composite pain score ≤ 1). According to the IDEAL classification, this study could be ranked as stage 2a (development). Conclusions: Our findings suggested that anterior hip pericapsular neurolysis using a modified approach could offer consistent and satisfactory analgesic and functional benefits to a majority of patients with inoperable hip fractures during the interim of the fracture healing process, and it was potentially safer than the conventional approach. This technique might have achieved its readiness to proceed to the next stage of research according to the IDEAL framework.

Comparison of three obturator nerve block techniques for injectate spread into the obturator canal: a randomized controlled trial

Purpose

The obturator nerve branches into the obturator canal; therefore, local anesthetic spread into the obturator canal predicts the success of the obturator nerve block (ONB). We compared three ONB techniques for the spread of local anesthetic mixed with contrast medium into the obturator canal.

Methods

We performed the ONB using the classical pubic approach (PA), inguinal approach (IA), or ultrasound-guided methodologic approach (UMA) in 143 patients undergoing transurethral resection of bladder tumors. The obturator nerve course and branching patterns of the UMA group were examined using ultrasound imaging. After injecting a local anesthetic mixed with a contrast medium, we evaluated its spread into the obturator canal using fluoroscopic imaging. P < 0.05 indicated statistical significance.

Results

Success rate of obturator canal enhancement was the greatest in the UMA group (84%; P < 0.001); the PA (42.6%; 20/47 patients) and IA (47.8%; 22/46 patients) groups did not differ significantly (P = 1.000). Both branches of the obturator nerve passed above the superior margin of the external obturator muscle (EOM), and the obturator canal was enhanced in 13 of 50 (26%) patients in the UMA group. The posterior branch of the obturator nerve passed between the superior and main fasciculi of the EOM in 37 of 50 patients (74%) in the UMA group; the obturator canal was enhanced in 29 of these 37 patients (78%).

Conclusion

Local anesthetic spread into the obturator canal using the UMA was superior to that using the PA and IA. Both branches of the obturator nerve could be blocked using the UMA.

From emergency department to operating room: interventional analgesia techniques for hip fractures

PURPOSE OF REVIEW

To provide an update on pain management options with regional anesthesia for patients with hip fractures at the emergency department (ED).

RECENT FINDINGS

Patients who sustain a hip fracture are typically admitted and diagnosed in the ED before being transferred to the operating room for surgery. Studies have clearly demonstrated the ability of the fascia iliaca compartment blocks (FICBs) and femoral nerve blocks (FNBs) to reduce pain and the risk of an acute confusional state. Their administration at an early stage of the patient's trajectory in the ED is beneficial. Recent anatomical studies contributed new knowledge of nociception in the hip joint, which allowed the development of more specific infiltration analgesia techniques without muscle weakness (e.g., pericapsular hip blocks). Further research on the timing of nerve blocks and an evaluation of new motor sparing techniques is indicated.

SUMMARY

FICB and FNB are established and recommended techniques in pain management for hip fracture patients. Their use early on in the ED may improve patient comfort and outcome. Pericapsular nerve hip blocks could provide a relevant alternative in future pain management in this group of patients.

Selective periarticular blocks for postoperative pain after hip and knee arthroplasty

PURPOSE OF REVIEW

This review aims to provide an overview of selective periarticular blocks for postoperative pain after hip and knee arthroplasty and the current evidence for their use.

RECENT FINDINGS

Most interventional analgesia techniques for hip and knee arthroplasty result in a motor block and muscle weakness. Therefore, these are not well suited for fast-track protocols. In contrast, selective pericapsular infiltration techniques provide selective joint sensory block without an associated motor block. This facilitates postoperative pain management and avoids impairing ambulation and early rehabilitation.

SUMMARY

The pericapsular blocks of the hip (pericapsular nerve group block, iliopsoas plane block, hip block), genicular nerves block, and infiltration between the popliteal artery and the capsule of the knee play an increasingly important role in providing postoperative analgesia after hip and knee arthroplasty without impeding fast-track protocols.

Obturator nerve block does not provide analgesic benefits in total hip arthroplasty under multimodal analgesic regimen: a randomized controlled trial

BACKGROUND AND OBJECTIVES

Although regional analgesia is considered an important component of optimal pain management, use of peripheral nerve blocks for total hip arthroplasty remains controversial. Since the obturator nerve innervates the anteromedial part of the joint capsule, we hypothesized that an obturator nerve block would decrease the opioid consumption after total hip arthroplasty.

METHODS

In this single center, prospective, triple blinded study, we randomly allocated 60 patients undergoing total hip arthroplasty under opioid-sparing total intravenous general anesthesia to a preoperative obturator nerve block or a sham block (placebo group) using 20 mL of ropivacaine 0.2% or saline, respectively. All patients received a multimodal analgesic regimen with non-opioid analgesics including periarticular local infiltration analgesia. The primary outcome was the intravenous opioid consumption in the post-anesthesia care unit.

RESULTS

Median (IQR) intravenous oxycodone consumption in the post-anesthesia care unit was 4 (2, 7.5) mg in the obturator nerve block group and 3 (0, 4) mg in the placebo group (p=0.05). There were no differences in pain scores between groups in the first 24 hours except at arrival on the surgical ward with significant higher pain scores in the placebo group (p=0.03). The ability to stand up and walk within 24 hours was comparable between groups as was the time to first walk (180 (90, 720) vs 240 (120, 780) min for the obturator nerve block and placebo groups, respectively; p=0.62).

CONCLUSIONS

Obturator nerve block did not improve postoperative opioid consumption after total hip arthroplasty performed under general anesthesia with a multimodal analgesic regimen.

TRIAL REGISTRATION NUMBER

NCT04085640.

Surgical treatment of proximal femoral fractures in high-risk geriatric patients under peripheral regional anesthesia : A prospective feasibility study

BACKGROUND AND OBJECTIVE

Due to changing demographics geriatric patients with multiple comorbidities and proximal femoral fractures are an increasing patient population. In these patient groups, peripheral regional anesthesia could become increasingly more important besides established procedures, such as neuraxial or general anesthesia. The aim of this single center feasibility study was to evaluate a combined blockade technique of the lumbosacral plexus for three predefined subgroups depending on the type of hip fracture.

METHODS

We used a unilateral double injection three-step technique to block the sacral (parasacral block) and lumbar plexus (anterior quadratus lumborum and psoas compartment block, n = 78). The blockade was performed both under ultrasound guidance and simultaneous nerve stimulation and 20 ml ropivacaine 0.375% was injected at each of the 3 injection sites (total dose 225 mg).

RESULTS

In 42% of cases the surgery was opioid-free (n = 33). In 5 patients a conversion to general anesthesia (insertion of a laryngeal mask and pressure-controlled or pressure-supported ventilation) was necessary (6%). The overall success rate of combination anesthesia (peripheral nerve blocks with supplemental sedative (propofol 1-2 mg/kg*h) or analgesic (incremental doses of 5 µg sufentanil) medication) was 94%, regardless of fracture type and surgical treatment.

CONCLUSION

The combined anesthetic technique presented in this study enables surgical treatment of proximal femoral fractures. The associated effort and requirement for expert knowledge in regional anesthesia indicates that this method should be considered especially in cases with high anesthetic risk, suitable sonoanatomy, and non-compromised coagulation.

A systematic review and meta-analysis of the hip capsule innervation and its clinical implications

Detailed understanding of the innervation of the hip capsule (HC) helps inform surgeons' and anaesthetists' clinical practice. Post-interventional pain following radiofrequency nerve ablation (RFA) and dislocation following total hip arthroplasty (THA) remain poorly understood, highlighting the need for more knowledge on the topic. This systematic review and meta-analysis focuses on gross anatomical studies investigating HC innervation. The main outcomes were defined as the prevalence, course, density and distribution of the nerves innervating the HC and changes according to demographic variables. HC innervation is highly variable; its primary nerve supply seems to be from the nerve to quadratus femoris and obturator nerve. Many articular branches originated from muscular branches of the lumbosacral plexus. It remains unclear whether demographic or anthropometric variables may help predict potential differences in HC innervation. Consequently, primary targets for RFA should be the anterior inferomedial aspect of the HC. For THA performed on non-risk patients, the posterior approach with capsular repair appears to be most appropriate with the lowest risk of articular nerve damage. Care should also be taken to avoid damaging vessels and muscles of the hip joint. Further investigation is required to form a coherent map of HC innervation, utilizing combined gross and histological investigation.

Pericapsular nerve group block: an overview

INTRODUCTION

The PENG block is a recently described ultrasound-guided technique for the blockade of the sensory nerve branches to the anterior hip joint capsule. It was described as an analgesic block for the acute pain management after hip fracture, while subsequent studies expanded the original indication. The aim of this narrative review was to summarize the existing knowledge about the PENG block from the anatomical bases and to provide an up-to-date description of the technique, applications and effects.

EVIDENCE ACQUISITION

We reviewed the following medical literature databases for publications on PENG block: PubMed, Google Scholar, EMBASE, and Web of science until August 31st, 2020. Data regarding anatomy, indications, drugs and technique were also collected, reported and discussed.

EVIDENCE SYNTHESIS

From our search result we selected 57 relevant publications. Among them, 36 were case reports or case series and 12 publication were letters or correspondence; no RCT was identified. The main indication is the hip-related analgesia. The most commonly injected drug is a 20ml long-acting local anesthetic. There are some cases of femoral and obturator nerve block, but no major complication such as hematoma/bleeding or needle-related organ injury has been reported yet.

CONCLUSIONS

The PENG block is a promising technique. Randomized controlled trials of high methodological quality are required to further elaborate the role of this block.

Topography and evidence of a separate "fascia plate" for the femoral nerve inside the iliopsoas - A dorsal approach

The femoral nerve stretch test is an essential part of clinical neurological examinations. This test is performed alongside Magnetic Resonance Imaging (MRI) to determine if there is any evidence of nerve root irritation, usually as a consequence of disc prolapse. The test occasionally gives false positive results. Why such false positives can occur, is subject to continued research, however, no obvious reason has yet emerged. We hypothesize that connectives of the femoral nerve may explain such a phenomenon. To see these connectives, we approached the femoral nerve from dorsal in 12 cases. With the use of ink injection into the subparaneural compartment of the femoral nerve and dissections, a thin transparent structure can clearly be seen that is separate from the epineurium, perineurium, and a paraneural sheath. A continuation of the paraneural sheath produces a fascia plate approximately 1.5 cm in width and with a thickness of around 3 mm, which not only circumnavigates the nerve but projects into the surrounding tissues. Our qualitative observations show that not only does this femoral nerve fascia plate exists, but it also contains nerves and vessels. Furthermore, we show that the femoral nerve is connected to the myofascial complex of the iliopsoas, and in a separate fascia plate from the iliopsoas fascia. This plate is a hitherto neglected connective which extends as far as the spinal dura mater. Evidence from our plastinates and histological sections suggests that when tension is applied to the femoral nerve during the femoral nerve stretch test, tension is also applied to the femoral nerve fascia plate. The femoral nerve fascia plate could be a specific factor that contributes to pain resulting in a false positive femoral nerve stretch test.

Adjunct Analgesia Reduces Pain and Opioid Consumption After Hip Arthroscopy: A Systematic Review of Randomized Controlled Trials

BACKGROUND

Patients who undergo hip arthroscopy inevitably experience pain postoperatively; however, the efficacy and safety of adjunct analgesia to prevent or reduce pain are not well-understood.

PURPOSE

To perform a comprehensive qualitative synthesis of available randomized controlled trials evaluating the effect of adjunct analgesia on postoperative (1) pain, (2) opioid use, and (3) length of stay (LOS) in patients undergoing hip arthroscopy.

STUDY DESIGN

Systematic review.

METHODS

PubMed, OVID/MEDLINE, and Cochrane Controlled Register of Trials were queried for studies pertaining to analgesia interventions for patients undergoing hip arthroscopy. Two authors independently assessed article bias and eligibility. Data pertaining to changes in pain scores, additional analgesia requirements, length of hospital stay, and complications were extracted and qualitatively reported. Network meta-analyses were constructed to depict mean pain, opioid use, and LOS among the 3 analgesia categories (blocks, local infiltration analgesia, and celecoxib).

RESULTS

Fourteen level 1 studies were included; 12 (85.7%) reported pain reductions in the immediate and perioperative period after hip arthroscopy. Of the 7 studies that assessed an intervention (2 celecoxib, 1 fascia iliaca block, 1 lumbar plexus block, 1 femoral nerve block, 1 intra-articular bupivacaine, 1 extracapsular bupivacaine) versus placebo, more than half reported that patients who received an intervention consumed significantly fewer opioids postoperatively than patients who received placebo (lowest P value = .0006). Of the same 7 studies, 2 reported significantly shortened LOS with interventions, while 4 reported no statistically significant difference in LOS and 1 did not report LOS as an outcome.

CONCLUSION

The majority of studies concerning adjunct analgesia for patients undergoing hip arthroscopy suggest benefits in pain reduction early in the postoperative period. There is mild evidence that adjunct analgesia reduces postoperative opioid use and currently inconclusive evidence that it reduces length of hospital stay. Furthermore, it appears that local infiltration analgesia may provide the greatest benefits in reductions in pain and opioid consumption. We recommend the use of adjunct analgesia in appropriately selected patients undergoing hip arthroscopy without contraindication who are at a high risk of severe postoperative pain.

Future in regional anesthesia: new techniques and technological advancements

Regional anesthesia has a very interesting long history, initially preferred over general anesthesia because of safety concerns, then for a period general anesthesia became safer and was preferred. The use of innovative technologies such as ultrasound technology has made the blocks safer and successful by directly visualizing targeted nerves and the location of local anesthetics. With the wide use of ultrasound in the regional anesthesia field success rate of peripheral nerve blocks increased and novel blocks techniques developed. Moreover, new extended-release local anesthetic agents have begun to be promising time-efficient and longer duration of analgesia with a single injection. In this article, we attempt to summarize some of the novel block techniques, pharmacological agents, and new technologies in the field of regional anesthesia.

Implementation of the Obturator Nerve Block into a Supra-Inguinal Fascia Iliaca Compartment Block Based Analgesia Protocol for Hip Arthroscopy: Retrospective Pre-Post Study

Background and Objectives: The effect of supra-inguinal fascia iliaca compartment block (SI-FICB) in hip arthroscopy is not apparent. It is also controversial whether SI-FICB can block the obturator nerve, which may affect postoperative analgesia after hip arthroscopy. We compared analgesic effects before and after the implementation of obturator nerve block into SI-FICB for hip arthroscopy. Materials and Methods: We retrospectively reviewed medical records of 90 consecutive patients who underwent hip arthroscopy from January 2017 to August 2019. Since August 2018, the analgesic protocol was changed from SI-FICB to SI-FICB with obturator nerve block. According to the analgesic regimen, patients were categorized as group N (no blockade), group F (SI-FICB only), and group FO (SI-FICB with obturator nerve block). Primary outcome was the cumulative opioid consumption at 24 hours after surgery. Additionally, cumulative opioid consumption at 6 and 12 hours after surgery, pain score, additional analgesic requests, intraoperative opioid consumption and hemodynamic stability, and postoperative nausea and vomiting were assessed. Results: Among 87 patients, there were 47 patients in group N, 21 in group F, and 19 in group FO. The cumulative opioid (fentanyl) consumption at 24 hours after surgery was significantly lower in the group FO compared with the group N (N: 678.5 (444.0–890.0) µg; FO: 482.8 (305.8–635.0) µg; p = 0.014), whereas the group F did not show a significant difference (F: 636.0 (426.8–803.0) µg). Conclusion: Our findings suggest that implementing obturator nerve block into SI-FICB can reduce postoperative opioid consumption in hip arthroscopy.

Effect of ultrasound-guided proximal and distal approach for obturator nerve block in transurethral resection of bladder cancer under spinal anesthesia

Background: Ultrasound-guided proximal or distal approach for obturator nerve block is preformed to prevent adductor muscle spasm during transurethral resection of bladder tumors. The aim of the study was to compare the effectiveness of two different techniques in blocking the obturator nerve during transurethral resection of a bladder tumor.

Methods: Fifty obturator nerve blocks were performed for transurethral bladder tumor resection and divided into two groups. One group received ultrasound-guided proximal obturator nerve block approach (proximal group), and the other group received ultrasound-guided distal obturator nerve block approach (distal group). Grade of adductor muscle spasm, the rate of clinical effectiveness, duration of block procedure, and complications were recorded. Patients with grade two adductor spasms were transferred to general anesthesia.

Results: Two patients in the distal group and one in the proximal group were transferred to general anesthesia for severe adductor muscle spasms. No difference was found in clinical effectiveness rate of obturator nerve block between the two groups. differed insignificantly. The number of patients who had no adductor muscle spasms in the proximal group was significantly higher than that of the distal group. Vascular puncture was detected in two patients in the proximal group and one patient in the distil group. No other complications were observed.

Conclusion: No difference was found for clinical effectiveness between the two groups. However, vascular puncture should receive more attention.

[Surgical treatment of proximal femoral fractures in high-risk geriatric patients under peripheral regional anesthesia : A clinical case series]

The authors describe in a clinical case series (n = 7) of older (age 78-95 years) high-risk patients the successful surgical treatment of proximal femoral fractures in a peripheral regional anesthesia technique. After positioning on the non-fractured side, a double injection technique (dual guidance concept: sonography plus nerve stimulation) was chosen. The injections were performed parasacrally (blockade of the sacral plexus under the piriformis muscle) and lumbar-paravertebrally (psoas compartment block and transmuscular quadratus lumborum block). Per block 15 ml ropivacaine 0.5% or 20 ml ropivacaine 0.375% was administered. The total dose of 225 mg ropivacaine was never exceeded. In 5 out of 7 cases a supplemental medication with 2 times 5 μg sufentanil (n = 2) and/or 1-1.5 mg/kg body weight and h propofol (n = 4) was administered with spontaneous breathing. In addition to potential benefits, the authors also discuss limitations of the procedure, for example by the use of oral anticoagulants.

Lower extremity regional anesthesia: essentials of our current understanding

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

Pericapsular Nerve Group (PENG) Block for Hip Fracture

Fascia iliaca block or femoral nerve block is used frequently in hip fracture patients because of their opioid-sparing effects and reduction in opioid-related adverse effects. A recent anatomical study on hip innervation led to the identification of relevant landmarks to target the hip articular branches of femoral nerve and accessory obturator nerve. Using this information, we developed a novel ultrasound-guided approach for blockade of these articular branches to the hip, the PENG (PEricapsular Nerve Group) block. In this report, we describe the technique and its application in 5 consecutive patients.

Update on Selective Regional Analgesia for Hip Surgery Patients

In hip surgery, regional anesthesia offers benefits in pain management and recovery. There are a wide range of regional analgesic options; none have shown to be superior. Lumbar plexus block, femoral nerve block, and fascia iliaca block are the most supported by published literature. Other techniques, such as selective obturator and/or lateral femoral cutaneous nerve blocks, represent alternatives. Newer approaches, such as quadratus lumborum block and local infiltration analgesia, require rigorous studies. To realize long-term outcome benefits, postoperative regional analgesia must be tailored to the individual patient and last longer.

Spread of injectate around hip articular sensory branches of the femoral nerve in cadavers

BACKGROUND

Anatomical knowledge dictates that regional anaesthesia after total hip arthroplasty requires blockade of the hip articular branches of the femoral and obturator nerves. A direct femoral nerve block increases the risk of fall and impedes mobilisation. We propose a selective nerve block of the hip articular branches of the femoral nerve by an ultrasound-guided injection in the plane between the iliopsoas muscle and the iliofemoral ligament (the iliopsoas plane). The aim of this study was to assess whether dye injected in the iliopsoas plane spreads to all hip articular branches of the femoral nerve.

METHODS

Fifteen cadaver sides were injected with 5 mL dye in the iliopsoas plane guided by ultrasound. Dissection was performed to verify the spread of injectate around the hip articular branches of the femoral nerve.

RESULTS

In 10 dissections (67% [95% confidence interval: 38-88%]), the injectate was contained in the iliopsoas plane staining all hip articular branches of the femoral nerve without spread to motor branches. In four dissections (27% [8-55%]), the injection was unintentionally made within the iliopectineal bursa resulting in secondary spread. In one dissection (7% [0.2-32%]) adhesions partially obstructed the spread of dye.

CONCLUSION

An injection of 5 mL in the iliopsoas plane spreads around all hip articular branches of the femoral nerve in 10 of 15 cadaver sides. If these findings translate to living humans, injection of local anaesthetic into the iliopsoas plane could generate a selective sensory nerve block of the articular branches of the femoral nerve without motor blockade.