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

Iliopsoas plane block does not improve pain after primary total hip arthroplasty in the presence of multimodal analgesia: a single institution randomized controlled trial

BACKGROUND

The clinical analgesic efficacy of iliopsoas plane block remains a subject of discussion. This study aimed to assess the analgesic efficacy of iliopsoas plane block under general anesthesia using multimodal analgesia.

METHODS

Fifty-six adult patients who underwent elective primary hip arthroplasty were enrolled. Patients were randomized to receive either a single-shot iliopsoas plane block (10 mL 0.75% ropivacaine with 1:200 000 epinephrine) or a sham block (10 mL normal saline). All patients received general anesthesia, multimodal analgesia (preoperative buprenorphine patch, 5 µg/h), intraoperative intravenous dexamethasone (8 mg) and nefopam (20 mg), and round-the-clock acetaminophen and celecoxib. The primary outcome was the numeric rating scale pain score at rest 6 hour after surgery.

RESULTS

Iliopsoas plane block did not have a notable advantage over the sham block in terms of pain relief at rest, as assessed by the numeric rating scale score, 6 hour after total hip arthroplasty (iliopsoas plane block: median, 4.0; IQR, 2.0-5.8; sham: median, 5.5; IQR, 2.3-6.8; median difference, -1.0; 95% CI -2.0 to 0.0; p≥0.999). Linear mixed model analysis showed no differences in pain scores, opioid consumption, quadriceps strength, or quality of recovery between the groups.

CONCLUSIONS

Iliopsoas plane block did not improve postoperative analgesia following total hip arthroplasty under general anesthesia with a multimodal analgesic regimen. The blockade of sensory femoral branches supplying the anterior hip capsule using iliopsoas plane block may not yield additional benefits concerning patient outcomes in the aforementioned clinical context.

TRIAL REGISTRATION NUMBER

NCT05212038, https://clinicaltrials.gov/ct2/show/NCT05212038.

Efficacy of iliopsoas plane block for patients undergoing hip arthroscopy: a prospective, triple-blind, randomized, placebo-controlled trial

BACKGROUND

Intraoperative stretching of the hip joint capsule often generates severe pain during the first 3 hours after hip arthroscopy. The short-lived severe pain mandates high opioid consumption, which may result in adverse events and delay recovery. The femoral nerve nociceptors are located anteriorly in the hip joint capsule. A femoral nerve block reduces pain and opioid demand after hip arthroscopy. It impedes, however, ambulation and home discharge after outpatient surgery. The iliopsoas plane block selectively anesthetizes the femoral sensory nerve branches innervating the hip joint capsule without compromising ambulation. We aimed to assess reduction of opioid consumption after iliopsoas plane block during the short-lived painful postsurgical period of time after hip arthroscopy.

METHODS

In a randomized, triple-blind trial, 50 patients scheduled for hip arthroscopy in general anesthesia were allocated to active or placebo iliopsoas plane block. The primary outcome was opioid consumption during the first three postoperative hours in the postanesthesia care unit. Secondary outcomes included pain, nausea, and ability to ambulate.

RESULTS

Forty-nine patients were analyzed for the primary outcome. The mean 3-hour intravenous morphine equivalent consumption in the iliopsoas plane block group was 10.4 mg vs 23.8 mg in the placebo group (p<0.001). No intergroup differences were observed for the secondary outcomes during the postoperative follow-up.

CONCLUSION

An iliopsoas plane block reduces opioid consumption after hip arthroscopy. The reduction of opioid consumption during the clinically relevant 3-hour postsurgical period of time was larger than 50% for active versus placebo iliopsoas plane block in this randomized, triple-blind trial.

Bibliometrics and knowledge map analysis of ultrasound-guided regional anesthesia

Through bibliometric analysis, we aim to comprehensively understand the research dynamics in this field, reveal key scientific research achievements and breakthrough discoveries, and provide valuable reference and guidance for future research directions. Utilizing the Web of Science, we retrieved the literature pertaining to ultrasonics-guided regional anesthesiology (1994-2022). CiteSpace and VOSviewer were used for bibliometric and knowledge mapping analysis. Our examination encompassed publication trends, authorship patterns, institutional contributions, frequently occurring keywords, keyword clustering, and emerging terminology trends. Of the 570 papers reviewed, there was a rising trend in publications each year. The main keywords in regional anesthesia were ultrasound guidance, nerve, analgesia, and pain score. Key research areas were regional anesthesia, ultrasound guidance, approach, pain score, and plane block. The U.S. led in research. Stanford University, University of Toronto, and Cork University Hospital were central institutions. Chan V was the top author with 24 articles, while Marhofer P was the most cited at 150 times. Regional anesthesia and pain medicine were the predominant journal in both publications and citations. In conclusion, research in this field consistently grew yearly, and visualization showcased trends in ultrasound-guided regional anesthesia. These visuals provided key bibliometric insights, helping researchers further explore and understand this domain.

Motor-sparing peripheral nerve blocks for hip and knee surgery

PURPOSE OF REVIEW

To summarize the recent literature describing and comparing novel motor-sparing peripheral nerve block techniques for hip and knee surgery. This topic is relevant because the number of patients undergoing same day discharge after hip and knee surgery is increasing. Preserving lower extremity muscle function is essential to facilitate early physical therapy for these patients.

RECENT FINDINGS

Distal peripheral nerve blocks may allow for preserved quadriceps motor strength and comparable analgesia to traditional techniques. However, few studies in hip and knee populations include strength or function as primary outcomes. For hip surgeries, studies have failed to show analgesic differences between regional blocks and periarticular infiltration. Similarly for knee arthroplasty in the absence of periarticular infiltration, recent evidence suggests adding combinations of blocks (ACB plus iPACK or genicular nerve blocks) may balance pain control and early ambulation.

SUMMARY

The use of motor-sparing peripheral nerve block techniques enables early ambulation, adequate pain control, and avoidance of opioid-related side effects facilitating outpatient/ambulatory lower extremity surgery. Further studies of these techniques for continuous peripheral nerve block catheters are needed to assess if extended blockade continues to provide motor-sparing and opioid-sparing benefits.

A randomized controlled trial of iliopsoas plane block vs. femoral nerve block for hip arthroplasty

BACKGROUND

Iliopsoas plane block (IPB) is a novel analgesic technique for hip surgery that retains quadriceps strength. However, evidence from randomized controlled trial is remains unavailable. We hypothesized that IPB, as a motor-sparing analgesic technique, could match the femoral nerve block (FNB) in pain management and morphine consumption, providing an advantage for earlier functional training in patients underwent hip arthroplasty.

METHODS

We recruited ninety patients with femoral neck fracture, femoral head necrosis or hip osteoarthritis who were scheduled for unilateral primary hip arthroplasty were recruited and received either IPB or FNB. Primary outcome was the pain score during hip flexion at 4 h after surgery. Secondary outcomes included quadriceps strength and pain scores upon arrival at post anesthesia care unit (PACU) and at 2, 4, 6, 24, 48 h after surgery, the first time out of bed, total opioids consumption, patient satisfaction, and complications.

RESULTS

There was no significant difference in terms of pain score during hip flexion at 4 h after surgery between the IPB group and FNB group. The quadriceps strength of patients receiving IPB was superior to those receiving FNB upon arrival at PACU and at 2, 4, 6 and 24 h after surgery. The IPB group showed a shorter first time out of bed compared to the FNB group. However, there were no significant differences in terms of pain scores within 48 h after surgery, total opioids consumption, patient satisfaction and complications between the two groups.

CONCLUSION

IPB was not superior to FNB in terms of postoperative analgesia for hip arthroplasty. However, IPB could serve as an effective motor-sparing analgesic technique for hip arthroplasty, which would facilitate early recovery and rehabilitation. This makes IPB worth considering as an alternative to FNB.

TRIAL REGISTRATION

The trial was registered prior to patient enrollment at the Chinese Clinical Trial Registry (ChiCTR2200055493; registration date: January 10, 2022; enrollment date: January 18, 2022; https://www.chictr.org.cn/searchprojEN.html ).

Parameters of Iliopsoas Plane Immediately Caudal to the Indirect Tendon of Rectus Femoris in Axial Plane Measured on Magnetic Resonance Images in an Adult Eastern Asian Population

The iliopsoas plane (IP) is a fascial plane deep to the iliopsoas complex and is the target of several novel ultrasound-guided analgesic interventions for hip. Currently, limited information is known about its parameters. From the pelvic magnetic resonance (MR) images of an adult Eastern Asian population (n = 49), the IP width, depth, and needle-beam angle in the axial plane immediately caudal to the level of indirect tendon of rectus femoris (RF) were found to be 10.7 ± 1.6 mm, 48.5 ± 15.5 mm, and 84.2 ± 8.2 degrees, respectively. There was a statistically significant difference in the age categories for IP width, and older patients seemed to have wider IP. Our data may provide applications for the technical modification of ultrasound-guided iliopsoas plane block (IPB) in acute hip pain management and the future development of ultrasound-guided single-needle-entry radiofrequency neuroablation in chronic hip pain management.

New ultrasound-guided capsular blocks for hip surgery: A narrative review

Surgery on the hip joint is very common. Improving pain management has been and is one of the fundamental pillars to optimize the functional recovery of patients. To do this, we must design a multimodal anesthetic-analgesic plan that covers the entire perioperative period. Peripheral nerve blocks and fascial blocks are an important component of multimodal analgesic strategies. Traditional blocks have moderate efficacy, prolonged motor impairment, and increased risk of falls. As an alternative, capsular blocks ("ileopsoas plane block" or "IPB" and pericapsular nerve group block or "PENG block") have recently been described that aim to avoid motor impairment while maintaining optimal analgesic efficacy. The objective of this review is to describe the new capsular blocks and to analyze whether they allow to improve postoperative analgesia and promote functional recovery with fewer complications, based on the innervation of the hip. To do this, a bibliographic review was carried out in the PubMed, Embase and Cochrane Library databases from January 2018 to June 2020.

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.

Analgesic effect of iliopsoas plane block for hip fracture

Background

Hip fracture and surgery are associated with moderate to severe pain, which hampers early mobilization and extends the hospital stay. Femoral nerve block and fascia iliaca compartment block could provide effective postoperative pain relief. Unfortunately, they could weaken the strength of the quadriceps muscle and increase the risk of falls. Iliopsoas plane block (IPB) is a novel motor-sparing regional technique, which targets the sensory branches of the hip joint originating from the femoral nerve. However, the analgesic effect of IPB has not been confirmed yet.

Case presentation

In the present case series, IPB and lateral femoral cutaneous nerve block were implemented under the guidance of ultrasound for eight patients with hip fractures. The median (IQR) visual analog scale (VAS) score (0–10; 0: no pain, 10: worst pain) decreased from 1.5 (0.25–2) before IPB to 0 (0–0) 0.5h after IPB at rest. The median (IQR) VAS score decreased from 8 (7–8) before IPB to 2 (1–2) 0.5h after IPB during flexion of hip 30°. Pain score was no more than one at rest and three during flexion of the hip 30° within 48h after surgery. Furthermore, the MMT grades of quadriceps strength were no less than four after IPB.

Conclusions

Our case series firstly highlights that IPB might be an effective analgesic technique for hip fracture and surgery, while retaining motor function.

Clinical Observation of Ultrasound-Guided Nerve Block Anesthesia on Postoperative Pain Control of Fracture Patients

To observe the postoperative pain control and clinical efficacy of ultrasound-guided nerve block anesthesia for patients with tibial fracture. A total of 128 patients with tibial fracture who received surgical treatment in our hospital from October 2020 to April 2021 were selected. The ultrasound guided anesthesia group and general anesthesia group were established by random number table method, with 64 patients in each group. Patients in the ultrasound-guided anesthesia group received ultrasound-guided nerve block anesthesia, and patients in the general anesthesia group received conventional general anesthesia. Observation times anesthetic effect in both groups, changes in hemodynamic parameters, digital pain scale (NRS) score as a result, compared two groups of patients with adverse reactions occur, change of the serum inflammatory factors indicators before and after operation, and USES the Pearson correlation coefficient analysis of the correlation between serum levels of inflammatory factor index and NRS score. The effect of anesthesia, postoperative recovery, directional force recovery, motor block and sensory block time of patients in ultrasound-guided anesthesia group decreased significantly than those in general anesthesia group (all P < 0.05). The comparison of MAP, HR and RR at T1 and T2 levels between the two groups was statistically significant (all P < 0.05). The changes of MAP, HR and RR in ultrasound guided anesthesia group were more stable than those in general anesthesia group.The NRS scores of patients in both groups showed an increasing trend with the extension of time. The 6 h, 12 h and 24 hNRS scores of patients in the ultrasound guided anesthesia group decreased significantly than those in the general anesthesia group (all P < 0.05). The total incidence of adverse reactions in ultrasound guided anesthesia group decreased significantly than that in general anesthesia group (P < 0.05).The serum levels of inflammatory factor interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in 2 groups increased significantly before surgery, and the levels of each index in ultrasound guided anesthesia group decreased significantly than that in general anesthesia group (ALL P < 0.05). Pearson correlation coefficient showed that serum IL-6 and TNF-α levels were positively correlated with NRS score (all P < 0.05). Ultrasound-guided nerve block anesthesia surgery can effectively improve the tibia fracture patients intraoperative anesthetic effect, improve patients with intraoperative and postoperative hemodynamic index of stability, the anesthesia surgery will exert positive effects on patients with postoperative pain control, can reduce the risk in patients with postoperative adverse reactions, reduce the postoperative patients with inflammatory factor activity. In addition, this paper found significant positive correlation between serum inflammatory factors IL-6 and TNF-α and NRF score, suggesting that serum IL-6 and TNF-α can be monitored for postoperative pain control in patients with tibial fracture, providing reference for improving postoperative treatment plan of patients.

Overview of the Innervation of the Hip Joint

The innervation of the hip joint has been investigated for over 200 years by anatomists and clinicians. Knowledge of the distribution and location of these nerves relative to anatomic landmarks visible with image guidance is important for optimizing nerve blocks and radiofrequency ablation procedures. In this article, the innervation of the anterior and posterior hip joint is reviewed, focusing on the source of articular branches, their course, termination, and relationship to anatomic landmarks. The innervation of the hip joint is multifaceted, with articular nerves originating from many sources in close proximity to and distant from the hip joint.

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.

Fascial plane blocks: a narrative review of the literature

Fascial plane blocks (FPBs) are increasingly numerous and are often touted as effective solutions to many perioperative challenges facing anesthesiologists. As 'new' FPBs are being described, questions regarding their effectiveness remain unanswered as appropriate studies are lacking and publications are often limited to case discussions or technical reports. It is often unclear if newly named FPBs truly represent a novel intervention with new indications, or if these new publications describe mere ultrasound facilitated modifications of existing techniques. Here, we present broad concepts and potential mechanisms of FPB. In addition, we discuss major FPBs of (1) the extremities (2) the posterior torso and (3) the anterior torso. The characteristics, indications and a brief summary of the literature on these blocks is included. Finally, we provide an estimate of the overall level of evidence currently supporting individual approaches as FPBs continue to rapidly evolve.

Anatomical considerations for obturator nerve block with fascia iliaca compartment block

This report reviews the topographical and functional anatomy relevant for assessing whether or not the obturator nerve (ON) can be anesthetized using a fascia iliaca compartment (FIC) block. The ON does not cross the FIC. This means that the ON would only be blocked by an FIC block if the injectate spreads to the ON outside of the FIC. Such a phenomena would require the creation of one or more artificial passageways to the ON in the retro-psoas compartment or the retroperitoneal compartment by disrupting the normal anatomical integrity of the FI. Due to this requirement for an artificial pathway, an FIC block probably does not block the ON.

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.

Peripheral nerve blocks for analgesia after elective total hip arthroplasty

A significant subgroup of patients suffer from moderate or severe pain after total hip arthroplasty (THA). Regional analgesia has the potential to reduce post-operative pain and thereby spare patients from opioids, but regional analgesia of the hip is complicated as the area is innervated by multiple nerves. However, the nociceptors of the hip joint are primarily innervated by the obturator and femoral nerves. The effect of an obturator nerve block (ONB) on pain following THA has never been investigated. A femoral nerve block is known to reduce pain after THA, but is unfortunately accompanied by an increased risk of fall. We have developed a novel nerve block-the iliopsoas plane block (IPB)-that has the potential to anaesthetize the hip articular sensory branches of the femoral nerve without causing motor blockade.

Editorial Commentary: Pain After Hip Arthroscopy-Are We Truly Addressing the Problem?

Pain after hip arthroscopy is a significant and challenging issue as is evidenced by the number of publications on this subject. Various analgesic strategies to circumvent this issue have been tried, with variable results. The central problem is that pain experienced by patients after hip arthroscopy is multifactorial in origin. Regarding local injection, an anatomic approach to the nerve supply to the hip with an effective pain relief strategy should take this into consideration and focus on using drugs with a low risk of complications and infiltration techniques that do not cause an unnecessary delay in rehabilitation and discharge of the patient. Furthermore, addressing traction time, surgical technique, and fluid extravasation and applying an individualized approach, keeping the patient's personality and profile in mind, will ensure adequate analgesia after arthroscopic intervention.

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.

An iliopsoas plane block does not cause motor blockade-A blinded randomized volunteer trial

BACKGROUND

A femoral nerve block relieves pain after total hip arthroplasty, but its use is controversial due to motor paralysis accompanied by an increased risk of fall. Assumedly, the iliopsoas plane block (IPB) targets the hip articular branches of the femoral nerve without motor blockade. However, this has only been indicated in a cadaver study. Therefore, we designed this volunteer study.

METHODS

Twenty healthy volunteers were randomly allocated to blinded paired active vs. sham IPB (5 mL lidocaine 18 mg/mL with epinephrine vs saline). The primary outcome was reduction of maximal force of knee extension after IPB compared to baseline. Secondary outcomes included reduction of maximal force of hip adduction, and the pattern of injectate spread assessed with magnetic resonance imaging.

RESULTS

Mean (confidence interval) change of maximal force of knee extension from baseline to after IPB was -9.7 N (-22, 3.0) (P = .12) (n = 14). The injectate was consistently observed in an anatomically well-defined closed fascial compartment between the intra- and extra-pelvic components of the iliopsoas muscle anterior to the hip joint.

CONCLUSION

We observed no significant reduction of maximal force of knee extension after an IPB. The injectate was contained in a fascial compartment previously shown to contain all sensory branches from the femoral nerve to the hip joint. The clinical consequence of selective anesthesia of all sensory femoral nerve branches from the hip could be a reduced risk of fall compared to a traditional femoral nerve block. Registration of Trial: The trial was prospectively registered in EudraCT (Reference: 2018-000089-12, https://www.clinicaltrialsregister.eu/ctr-search/search?query=2018-000089-12).

An Obturator Nerve Block does not Alleviate Postoperative Pain after Total Hip Arthroplasty: a Randomized Clinical Trial

BACKGROUND AND OBJECTIVES

A substantial group of patients suffer from moderate to severe pain following elective total hip arthroplasty (THA). Due to the complex innervation of the hip, peripheral nerve block techniques can be challenging and are not widely used. Since the obturator nerve innervates both the anteromedial part of the joint capsule as well as intra-articular nociceptors, we hypothesized that an obturator nerve block (ONB) would decrease the opioid consumption after THA.

METHODS

Sixty-two patients were randomized to receive ONB or placebo (PCB) after primary THA in spinal anesthesia. Primary outcome measure was opioid consumption during the first 12 postoperative hours. Secondary outcome measures included postoperative pain score, nausea score and ability to ambulate.

RESULTS

Sixty patients were included in the analysis. Mean (SD) opioid consumption during the first 12 postoperative hours was 39.9 (22.3) mg peroral morphine equivalents (PME) in the ONB group and 40.5 (30.5) mg PME in the PCB group (p=0.93). No difference in level of pain or nausea was found between the groups. Paralysis of the hip adductor muscles in the ONB group reduced the control of the operated lower extremity compared with the PCB group (p=0.026). This did, however, not affect the subjects' ability to ambulate.

CONCLUSIONS

A significant reduction in postoperative opioid consumption was not found for active versus PCB ONB after THA.

TRIAL REGISTRATION NUMBER

NCT03064165 and 2017-000068-14.