Peng block in prosthetic hip replacement: A cadaveric radiological evaluation

PENG for chronic pain: the clinical effectiveness of pericapsular nerve group block in chronic hip pain

OBJECTIVES

To evaluate the efficiency and tolerability of pericapsular nerve group block (PENG) for the treatment of chronic hip pain.

METHODS

This is a retrospective, single-centre, 4-group study conducted over a 3-month period to find out the most typical cause of chronic hip pain. A total of 112 patients with symptomatic hip osteoarthritis (OA), Stage 2-3, greater trochanteric pain (GTPS) and chronic pain after total hip arthroplasty (cTHA), who had an ultrasound-guided PENG block, were selected. To assess the effectiveness of the treatment, the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) and visual analogue scale (VAS) scores of the patients prior to treatment were compared with their scores after the 1st week, 1st month, and 3rd month of treatment. The study also aimed to analyse the patients' initial feelings of alleviation following the block (1st VAS/2) and problems experienced both during and after the block.

RESULTS

The parameters studied included pain, stiffness, and results of physical activity in the 1st week, 1st month, and 3rd month following PENG block application. At the beginning of the 1st week, of the 112 patients who were administered a PENG block for hip pain, we reported a 62% improvement in pain, a 52% reduction in stiffness, and a 53% increase in physical activity. Even though these results slightly declined in the 1st and 3rd months, the rates were still higher than 45%.

CONCLUSIONS

Overall, the PENG block was well-tolerated by the patients in our study. No treatment-related infections or any other serious complications were observed.

Comparison between supra-inguinal fascia iliaca and pericapsular nerve group blocks on postoperative pain and functional recovery after total hip arthroplasty: A noninferiority randomised clinical trial

BACKGROUND

Pain after a posterolateral approach for total hip arthroplasty (THA) may affect early functional recovery. Supra-inguinal fascia iliaca (SFIB) and pericapsular nerve group (PENG) blocks have been proposed as promising analgesia techniques.

OBJECTIVES

This trial was conducted to compare a PENG with a SFIB for controlling postoperative pain and for providing functional recovery.

DESIGN

Noninferiority monocentric randomised controlled study.

SETTING

One hundred and two patients scheduled for a total hip arthroplasty via the posterolateral approach under spinal anaesthesia were prospectively allocated to two groups. Data acquisition occurred between October 2021 and July 2022 at the University Hospital of Liege.

PATIENTS

One hundred and two patients completed the trial.

INTERVENTIONS

Group SFIB received supra-inguinal fascia iliaca block (SFIB) (40 ml ropivacaine 0.375%), whereas group PENG received a PENG block (20 ml ropivacaine 0.75%).

MAIN OUTCOME MEASURES

Rest and mobilisation pain on a 0 to 10 numeric rating scale at fixed time points: 1 and 6 h after surgery, on day-1 and day-2 at 8 a.m.,1 p.m. and 6 p.m. On day-1 and day-2, evolution of quality-of-recovery-15 score was assessed, and timed-up-and-go, 2 and 6 min-walking tests. The noninferiority margin was set as 1 numeric rating scale point 6 h after surgery.

RESULTS

Six hours after surgery, pain scores in group PENG were noninferior to those of group SFIB, with a difference between medians at 0 (95% CI -0.93 to 0.93). There were no significant differences between the groups regarding rest and dynamic pain trajectories during the first 48 postoperative hours, with no significant effects of group (rest P  = 0.800; dynamic P  = 0.708) or interaction between group and time (rest P  = 0.803; dynamic P  = 0.187). Similarly, no significant differences were observed regarding motor and functional recovery as assessed by timed-up-and-go ( P  = 0.197), 2 min ( P  = 0.364), and 6 min walking ( P  = 0.347) tests and quality-of-recovery-15 ( P  = 0.417) score.

CONCLUSION

Following a total hip arthroplasty via the posterolateral approach, a PENG block is noninferior to SFIB regarding postoperative pain control 6 h after surgery, and functional recovery.

TRIAL REGISTRATION

European Clinical Trial Register under EudraCT-number 2020-005126-28 ( https://www.clinicaltrialsregister.eu/ctr-search/trial/2020-005126-28/BE ).

Combining Pericapsular Nerve Group (PENG) Block With the Supra-Inguinal Fascia Iliaca Block (SIFICB) for Perioperative Analgesia and Functional Recovery in Patients Undergoing Hip Surgeries: A Retrospective Case Series

BACKGROUND

The complex innervation of the hip joint may require a combined peripheral nerve block technique for perioperative effective analgesia and early recovery. The pericapsular nerve group (PENG) and suprainguinal fascia iliaca compartment blocks (SIFICB) are interfascial plane blocks aiming to involve the femoral, obturator, accessory obturator, and lateral femoral cutaneous nerves. The data still lacks in providing the standard of care for patients undergoing hip surgery. In this case series, we studied the efficacy of ultrasound-guided combined PENG block and SIFICB for perioperative analgesia and functional recovery in patients posted for hip surgery.

METHOD

We studied 10 adults of either gender who underwent close reduction and internal fixation of hip fracture. Before receiving spinal anesthesia, all patients had PENG block and SIFICB with 10 ml and 20 ml of local anesthetics respectively. Patients were observed for ease of giving sitting position for spinal anesthesia (EOSP), visual analogue score (VAS) at rest and 15° leg elevation, duration of postoperative analgesia, the cumulative requirement of rescue analgesic at 48 hours and ability of patients to undergo weight-bearing trial postoperatively.

RESULT

The static and dynamic VAS before receiving spinal anesthesia and postoperatively, was reduced compared to pre-block. The optimal position for delivering spinal anesthesia was possible to achieve as the patients were able to sit comfortably after 10 minutes of receiving both blocks. Duration of postoperative analgesia also extended up to 18 hours with the cumulative requirement of injection tramadol restricted to two doses postoperatively. All were able to walk down a minimum of 55 steps after 48 hours of completion of surgery.

CONCLUSION

Combining PENG block along with SIFICB is effective in the provision of perioperative analgesia with a considerable reduction in opioids and enhanced functional recovery due to motor sparing effect after surgical repair of the hip fracture.

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.

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 in hip surgery. An alternative that goes beyond what we know?

Hip fracture is a pathology usually observed in older patients, prone to complications and increased morbidity and mortality during hospital admission. The PENG (Pericapsular Nerve Group) block has recently been described to provide higher quality analgesia, favoring early ambulation. The literature search was carried out from November 2018 to July 2021 with the following keywords: pericapsular nerve group block and PENG block. Studies conducted in the pediatric population or in adults with an indication other than hip surgery were excluded; obtaining 18 articles to read in full text. The analyzed studies had positive results in favor of performing the PENG block in hip surgery. Unfortunately, the current evidence is insufficient to be able to integrate the results obtained and draw conclusions about the effectiveness and safety of the PENG block.

The analgesic efficacy of pericapsular nerve group block in patients with intertrochanteric femur fracture: A randomized controlled trial

Background

The aim of this study is to evaluate analgesic efficacy of pericapsular nerve group (PENG) block in patients with intertrochanteric femur fracture (IFF).

Methods

This double-blinded randomized controlled trial in patients with IFF scheduled for proximal femoral nail antirotation (PFNA) between December 2020 and November 2021. The primary outcome was VAS scores during exercising at 6 h after surgery; secondary outcomes were pain during exercising and rest, intraoperative dose of remifentanil, cumulative dose of postoperative fentanyl, postoperative analgesia satisfaction scores, and ratio of quadriceps weakness.

Results

A total of 50 patients were randomly divided into PENG block group (n = 25) or fascia iliaca compartment block (FICB) group (n = 25). Exercising VAS scores at 6 h after surgery were significantly lower in PENG block group than that in FICB group (2 (2, 4) vs. 6 (4, 7), P < 0.001). The intraoperative dose of remifentanil and cumulative dose of postoperative fentanyl by patient-controlled intravenous analgesia within 24 h after surgery in PENG block group were significantly lower than in FICB group (both P < 0.001). Postoperative analgesia satisfaction scores in PENG block group were significantly higher than those in FICB group (P = 0.016). The ratio of quadriceps weakness at 6 h after surgery was significantly higher in FICB group than PENG block group (48% vs. 0%, P < 0.001).

Conclusions

Compared to FICB, ultrasound-guided PENG block may provide better postoperative pain relief in patients with IFF, with less pronounced quadriceps weakness.

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.

Surgeon-performed pericapsular nerve group (PENG) block for total hip arthroplasty using the direct anterior approach: a cadaveric study

Background

During total hip arthroplasty (THA) using the direct anterior approach, orthopaedic surgeons can identify all anatomical landmarks required for pericapsular nerve group (PENG) blocks and carry out the latter under direct vision. This cadaveric study investigated the success of surgeon-performed PENG block. Success was defined as dye staining of the articular branches of the femoral and accessory obturator nerves.

Methods

11 cadavers (18 hip specimens) were included in the current study. To simulate THA in live patients, an orthopaedic surgeon inserted trial prostheses using the direct anterior approach. Subsequently, a block needle was advanced until contact with the bone (between the anterior inferior iliac spine and iliopubic eminence). 20 mL of 0.1% methylene blue was injected. Cadavers were then dissected to document the presence and dye staining of the femoral, lateral femoral cutaneous, obturator and accessory obturator nerves as well as the articular branches of the femoral, obturator and accessory obturator nerves.

Results

Methylene blue stained the articular branches of the femoral nerve and the articular branches of the accessory obturator nerve (when present) in all hip specimens. Therefore, surgical PENG block achieved a 100% success rate. Dye stained the femoral and obturator nerve in one (5.6%) and two (11.1%) hip specimens, respectively. No dye staining was observed over the accessory obturator nerve in the pelvis nor the lateral femoral cutaneous nerve.

Conclusion

Surgeon-performed PENG block during direct anterior THA reliably targets the articular branches of the femoral and accessory obturator nerves. Future trials are required to compare surgeon-performed PENG block with anaesthesiologist-performed, ultrasound-guided PENG block, and surgeon-performed periarticular local anaesthetic infiltration.

Landmark-guided pericapsular nerve group (PENG) block for reduction of dislocated prosthetic hip: A case report

Dislocated hip joint is a painful condition, which requires urgent reduction. Previously, ultrasound (US)-guided pericapsular nerve group (PENG) block has been used for reduction of dislocated prosthetic hip. We have used landmark-guided PENG block in two patients of dislocation of prosthetic hip. We suggest that the landmark-guided technique of PENG block can be used safely and successfully as an alternative technique, where US facility is not available.

Permeable spaces between glenohumeral ligaments as potential gateways for rapid regional anesthesia of the shoulder

Shoulder pain is a highly prevalent condition, often resulting in major life limitations, and requiring effective treatments. In this work, we explore the anatomical basis of a proposed approach to the regional anesthesia of the shoulder through a single injection under the subscapularis muscle. Bilateral experimental injections in shoulders from body donors (Radiolar ® and Methylene-Blue) under the subscapular muscle (n = 11) and cadaveric systematic dissections of other 35 shoulders from body donors were performed. Injectate spread was then qualitatively assessed. Long axis of permeable foramina in the anterior aspect of the shoulder joint capsule was measured in centimeters using a digital caliper. More than 40% of specimens had at least one permeable space (Weitbrech and/or Rouvière foramina) communicating the subscapular bursa and the articular space. We further demonstrate that an ultrasonography-guided injection under the subscapularis muscle allows the spread of the injectate through the anterior, inferior and posterodorsal walls of the articular capsule, the subacromial bursa, and the bicipital groove, as well as into the articular space for some injections. The odds of accidental intraarticular injection decrease when injecting with low volumes. This anatomical study provides a detailed description of foramina between glenohumeral ligaments. Furthermore, the data shown in this work supports, as a proof of concept, a safe alternative for rapid and specific blockade of terminal sensory branches innervating the shoulder joint capsule.

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.