Radiofrequency Procedures to Relieve Chronic Hip Pain: An Evidence-Based Narrative Review

Effect of bupivacaine concentration on ultrasound-guided pericapsular group nerve block efficacy in hip surgery patients: comparative, randomized, double-blinded clinical trial

Background

The pericapsular nerve group (PENG) block offers effective postoperative pain relief following hip fracture surgery. This research investigated three doses of bupivacaine, all administered in the same total volume, for performing ultrasound-guided PENG blocks during hip fracture procedures.

Methods

This randomized, double-blinded clinical trial was conducted on 135 patients aged between 18 and 70 years of both sexes who underwent hip fracture surgeries. Participants were randomized into three groups (n = 45). Ultrasound-guided PENG block was applied, the groups received 20 mL of local anesthetics. The first group received 0.5% bupivacaine, the second group received 0.375% bupivacaine, and the third group received 0.25% bupivacaine. The following parameters were recorded: onset of sensory block, resting NRS after passively raising the limb by 15° half an hour post-procedure, quality of recovery score (QoR-15) at 24 h postoperative.

Results

The 0.25% bupivacaine group exhibited a longer sensory block onset than the other groups (p ≤ .05). Significant differences were demonstrated between the groups regarding the time to 1st analgesia (p = .033) and total morphine consumption (p = .025). NRS at baseline and T30 post-block did not show significant differences between the studied groups. No significant differences were detected postoperatively in rest and dynamic NRS (p ≤ .05). Patient satisfaction, QoR-15 score, and ease of spinal positioning did not differ between the groups.

Conclusion

Compared to 0.25% bupivacaine, PENG block with 0.5% and 0.375% bupivacaine provided a rapid onset sensory block, delayed first analgesic requirements, and reduced total morphine consumption after hip surgeries.

Protocol Registration

The trial was registered at the clinicaltrials.gov with study number (Trial ID: NCT05788458).

Hip chronic pain: ultrasound guided ablation of anterior articular branches plus posterior neurolysis of the nerve to the quadratus femoris versus the alone anterior approach-a retrospective observational study

INTRODUCTION

Chronic hip pain is a common painful condition in the elderly population. A mini invasive technique that is increasingly being considered for management of CHP is the percutaneous denervation of hip articular branches via radiofrequency ablation. We described a new ultrasound-guided technique based on the combination of 90° ultrasound-guided anterior radiofrequency ablation of the articular branches of femoral nerve, accessory obturator nerve and obturator nerve for anterior hip, combined with 90° ultrasound-guided ablation of the articular branches of the nerve of the quadratus femoris for posterior pericapsular neurolysis of the hip.

MATERIAL E METHODS

We retrospectively analyzed the medical records of patients from September 2022 to September 2023 treated for chronic hip pain in the ambulatory of Pain Management, identifying 22 patients who underwent ultrasound guided radiofrequency denervation of anterior hip articular branches alone (Group B); and 22 patients in which was also applied a radiofrequency denervation of the posterior articular branches, in addition to the anterior denervation (Group A). We analysed the pain intensity of both groups measured with numeric rating scale.

RESULT

The combined anterior plus posterior approach ensured that the results obtained were maintained 6 months after the procedure (T3) with excellent pain control and an average NRS of 1455 for group A. While for the group B, with the anterior approach alone, the NRS at six months showed an upward trend with an average NRS of 3818. The dual approach is more effective in pain relief at 6 months with a statistically significant difference in NRS values (p < 0.001).

CONCLUSION

This retrospective observational study highlighted the greater impact of the double approach (anterior plus posterior) in the denervation of the hip joint, compared to anterior neurolysis alone.

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.

The effect of conventional radiofrequency thermocoagulation of femoral and obturator nerves' articular branches on chronic hip pain: a prospective clinical study

BACKGROUND

Chronic hip pain is one of the most common and difficult-to-treat causes of disability. Our study's primary aim was to investigate the effects of ultrasound and fluoroscopy-guided radiofrequency thermocoagulation of the femoral and obturator nerve articular branches on chronic hip pain, and the secondary aim was to determine its effects on hip function and quality of life.

METHODS

Fifty-three patients with hip pain lasting more than three months were enrolled in the study. VPS scale and WOMAC, SF-12 questionnaires were applied to the patients before and in the first, third, and sixth months following the procedure.

RESULTS

Of the patients, 60.4% were female, and 39.6% were male. Hip pain was caused by osteoarthritis in 77.1%, postoperative hip pain in 12.5%, malignancy in 8.3%, and avascular necrosis in 2.1%. The VPS scores were 8.9 ± 1.1 (mean±SD) in the baseline period, 2.4 ± 2.5 in the first postoperative week, 3.8 ± 2.5 in the first month, 5.1 ± 2.8 in the third month, and 5.8 ± 2.7 in the sixth month, with a significant decrease in VPS score (P < .001). One patient developed a motor deficit that improved spontaneously.

CONCLUSIONS

We concluded that radiofrequency thermocoagulation application to the articular branches of the femoral and obturator nerves provides pain relief, hip function improvement, and better quality of life (better physical component scores but no improvement in mental component scores in SF-12) for up to 6 months in chronic hip pain.

Bipolar radiofrequency ablation lesion areas and confluence: An ex vivo study and technical report

INTRODUCTION

Radiofrequency ablation (RFA) has been used for nearly 100 years, treating an array of medical conditions including chronic pain. Radiofrequency (RF) energy depolarizes and repolarizes tissues adjacent to a probe producing heat and causing direct thermal injury. When positioned adjacent to neural structures, it leads to neural tissue injury and cell death interrupting pain signaling with the ultimate goal of providing lasting pain relief. Today, RFA is commonly used to treat cervical, thoracic, and lumbar zygapophyseal joints, sacroiliac joint, and more recently large peripheral joint-mediated pain. There are several applications of RFA systems, including bipolar, conventional thermal, cooled, protruding, and pulsed. As yet, no study has determined the best technical practice for bipolar RFA.

OBJECTIVE

This ex vivo study examines RFA lesion midpoint (LMP) area and lesion confluence comparing three different commonly used gauge (g) probes (18-g, 20-g, and 22-g) with 10-mm active tips at various interprobe distances (IPD) to guide best technical practices for its clinical application.

METHODS

Bipolar RFA lesions were generated in preservative-free chicken breast specimens using three different gauge probes (18-g, 20-g, and 22-g) with 10-mm active tips at various IPD (6, 8, 10, 12, 14, 16, and 18 mm). RF was applied for 105 s (15-s ramp time) at 80°C for each lesion at both room and human physiological temperature. The specimen tissues were dissected through the lesion to obtain a length, width, and depth, which were used to calculate the LMP area (mm2 ). The LMP areas of each thermal ablation were investigated using visualization and descriptive analysis. The Kruskal-Wallis test was performed to compare LMP areas between the two temperature groups and the three different gauge probe subgroups at the various IPDs.

RESULTS

Of the 36 RF lesions (14: 18-g, 12: 20-g, and 10: 22-g) performed, 24 demonstrated lesion confluence. The average time to reach 80°C was 16-17 s; therefore, the average time of RF-energy delivery (at goal temperature) was 88-89 s despite varying needle size or IPD. Comparing the 25 and 37°C groups, 18-g probes produced mean LMP areas of 73.7 and 79.2 mm2 , respectively; 20-g probes produced mean LMP areas of 66 and 66.8 mm2 , respectively; 22-g probes produced mean LMP areas of 56.6 and 59.7 mm2 , respectively. There was no statistical evidence to state a difference regarding LMP area between temperature groups; however, the 18-g probes produced consistently larger LMP areas in the 37°C compared to 25°C specimen groups at each IPD. Lesion confluence was lost for 18-g, 20-g, and 22-g probes at IPD of 14, 12, and 10 mm, respectively, in both 25 and 37°C groups. LMP area was similar between 6 and 8 mm IPD in all of the three-gauge groups; however, there was a significant drop in LMP area from 8 mm IPD to 10 mm and greater. The 18-g, 20-g, and 22-g probes all demonstrated a sharp decline in LMP area when increasing the IPD from 8 to 10 mm.

CONCLUSION

This ex vivo technical study evaluated bipolar RFA LMP areas and lesion confluence, and determined the recommended IPD of 18-g, 20-g, and 22-g probes to be less than 12, 10, and 8 mm, respectively, for best clinical practice. Placing bipolar probes at an IPD greater than 14, 12, and 10 mm, respectively, risks the loss of lesion confluence and failure to produce a clinically significant treatment response due to lack of nerve capture. In clinical practice, the use of injectate may produce larger lesions than demonstrated in this study. Additionally, in vivo factors may impact ablation zone size and ablation patterns. As there are a paucity of studies comparing various RFA applications and conventional RFA needles are least expensive, it is possible that bipolar conventional RFA is more cost-effective than other techniques.

Ultrasound-Guided Radiofrequency Ablation for Chronic Hip Pain Due to Osteoarthritis

BACKGROUND AND AIMS

Hip osteoarthritis (OA) has a prevalence of 2.9% in Portugal and is a related cause of pain and disability. A sufficient number of patients report these symptoms even after total hip arthroplasty (THA), while others are contraindicated to such surgery and suffer from uncontrolled pain. Percutaneous denervation of hip nerve branches using radiofrequency ablation (RFA) has emerged as a powerful therapeutic avenue to consider for patients with chronic hip pain.

METHODS

Between January 2020 and March 2021, 26 patients with chronic hip pain received ultrasound-guided RFA with a pericapsular nerve group (PENG) block technique adaptation. Patients suffering from chronic hip pain for more than three months with radiographic evidence of osteoarthritis were included. A numeric rating scale (NRS) and pain medication reduction were defined as outcome variables assessed before treatment and at three-, six-, nine-, and 12-month follow-ups.

RESULTS

All selected patients underwent the procedure. All the patients had hip osteoarthritis. Twelve-month follow-up data revealed a statistically significant decrease in the numeric rating scale. The mean NRS for pain was 2 after the procedure. Over 75% of patients reported >50% pain relief during the follow-up and 85% reduced pain medication consumption. No side effects were reported.

CONCLUSION

Hip sensory articular branch RFA is a treatment option with interesting outcomes for chronic hip pain, as demonstrated by our study.

Ultrasound-Guided Peripheral Nerve Blocks for Hip Surgery: A Concise Perspective

Ultrasound implementation for the facilitation of peripheral nerve blocks is well established. Ultrasound-guided lumbar plexus, femoral, fascia iliaca and supra-inguinal fascia iliaca compartment, pericapsular nerve group and quadratus lumborum nerve blocks have been employed for analgesia purposes in hip surgery. The combination of motor-sparing regional anesthesia strategies for optimal postoperative pain control with recovery protocols targeting to early and safe patients' mobilization constitute the current dogma of orthopedic surgery. Therefore, this editorial sets out to revisit the role of peripheral nerve blocks in postoperative pain management of hip surgery patients, under the prism of current orthopedic practice.

Novel Ultrasound-Guided Radiofrequency Ablation of the Medial Epicondylar Sensory Nerve for Recalcitrant Medial Epicondylosis: A Case-Based Technical Report

Recalcitrant medial epicondylosis (ME) is a chronic tendinopathy affecting the common flexor-pronator tendon origin which causes significant pain and functional limitations. Recalcitrant ME is difficult to manage with non-surgical treatment options. The medial epicondylar sensory nerve (MEsn) is a small sensory nerve that travels within the medial intermuscular septum to innervate the osseous-tendinous structures of the medial epicondyle. In this report, we describe a novel technique for the treatment of recalcitrant ME via radiofrequency ablation (RFA) of the MEsn under ultrasound guidance. The MEsn is localized under ultrasound in the medial distal arm, just proximal to the medial epicondyle. Patients with a positive prognostic block of the MEsn subsequently underwent RFA of the MEsn. We have performed this procedure on two patients who have demonstrated improvement in pain and function for up to nearly one year after the procedure. The relief from pain and improvement in function of these patients warrants further investigation and comparative trials with respect to conventional treatment options, as MEsn RFA may be a viable treatment option for recalcitrant ME.

Interventional Therapies for Osteoarthritis: An Update

Osteoarthritis (OA) is one of the most common diseases worldwide and is expected to increase in incidence as the age of the general population rises. Both oral medications, such as NSAIDs, and surgical treatments used for OA management have limitations. Demand is rising for minimally invasive techniques such as intraarticular injections and percutaneous interventions for use in place of or in conjunction with oral medications and surgical therapies, and the past 2 decades have seen a rapid expanse in both pharmacologic and nonpharmacologic minimally invasive OA treatments. Image guidance with fluoroscopy, CT, or ultrasound is often used in conjunction with these procedures to achieve precise treatment localization to achieve maximal therapeutic effect. The choice of modality used for image guidance is often influenced by clinician experience, patient characteristics, and equipment availability. This article reviews the mechanisms of action, contraindications, complications, and efficacy of conventional and developing minimally invasive OA treatments. The minimally invasive treatment options described in this Review include therapeutic injections such as antiinflammatory agents, viscosupplements, and biologics, as well as nonpharmacologic treatments of subchondroplasty, nerve ablation, genicular artery embolization, intraarticular pulsed radiofrequency therapy, and MRI-guided focused ultrasound therapy.

The difficulty of choosing the method of analgesia after total replacement of the lower limb large joints (case report, literature review)

A case of successful treatment of a patient with a periprosthetic fracture of the femur is described. The fracture occurred one day after total hip replacement as a result of a fall, possibly associated with postoperative conduction analgesia. Lower limb large joints total replacement may become the most frequently performed type of elective surgery already in the current decade. The increasing prevalence of osteoporosis, osteoarthritis, rheumatic diseases and hip fractures is an objective prerequisite for it. Despite of all efforts, the problem of postoperative pain control during these surgical interventions currently remains unresolved. There is currently no “gold standard” for pain relief after total hip and knee replacement surgeries. An excellent ratio of effectiveness and safety is demonstrated by multimodal pain relief programs based on peripheral nerve blocks. However, while having undeniable advantages, conduction anesthesia/analgesia has a critically important drawback. The cornerstone of postoperative rehabilitation for patients undergoing total hip or knee replacement is their early activation. All methods of conduction anesthesia are associated with motor blockade. In particular, femoral nerve block causes weakness of quadriceps muscle of thigh, inducing patients’ inadvertent falling when attempting to stand or walk. The situation with the choice of the method of anesthesia after total replacement of the lower limb large joints can be described as “a long way to go”.

Role of N-Methyl-D-Aspartate Receptor NR2B Subunit in Inflammatory Arthritis-Induced Chronic Pain and Peripheral Sensitized Neuropathic Pain: A Systematic Review

Arthritis is a common clinical disease that affects millions of people in the world. The most common types of arthritis are osteoarthritis and rheumatoid arthritis. Inflammatory arthritis (IA), a chronic painful disease, is characterized by synovitis and cartilage destruction in the early stages. Pathologically, IA causes inflammatory changes in the joints and eventually leads to joint destruction. Pain is associated with inflammation and abnormal regulation of the nervous system pathways involved in pain promotion and inhibition. In addition, the occurrence of pain is associated with depression and anxiety. We found that there are many factors affecting pain, in addition to inflammatory factors, glutamate receptor may be the possible cause of long-term chronic pain caused by IA. N-methyl-d-aspartate receptor subunit 2B (NR2B) has been reported to involved in IA and nervous system diseases, especially peripheral neuropathic pain. In this review, we summarized the mechanisms of the NR2B subunit of the N-methyl-D-aspartate (NMDA) receptor in peripheral nerve sensitization during IA and chronic pain.

Ultrasound guided Fascia Iliaca Block versus Pericapsular Nerve Group for Postoperative Analgesia Prior to Spinal Anaesthesia for Hip Surgeries

For evaluating per capsular nerve group (PENG) block’s analgesic effect on elderly patient’s suffering from femoral neck fracture undergoing hip arthroplasty to provide a basis for optimizing perioperative analgesia in hip arthroplasty. This is a Prospective Observational study conducted in patients scheduled to undergo surgery for hip fracture under spinal anesthesia in Department of Anaesthesiology, Sapthagiri Institute of Medical Sciences and Research centre, Bengaluru, Karnataka. As per previous studies a total of 40 patients were included in the study over a period of 6 months. A prospective study was conducted after obtaining approval by the institutional ethics committee and informed written consent, patient scheduled for hip fracture surgery under spinal anesthesia based on inclusion criteria was randomly divided into two groups as group FIB and group PENG. Total 40 patients were included in the current study. The demographic data of both the groups are presented. There was no statistically significant difference in both groups with respect to demographic characteristics. VAS score for pain before nerve block between Group P (8.4 ± 0.58) and Group F (8.1 ± 0.61) was comparable (p = 0.9983).

CT-Guided Cooled Radiofrequency Denervation for Chronic Arthritis Pain of the Hip and Shoulder

The paradigm in the treatment of arthritis pain is shifting for previously open surgical denervations of the hip and shoulder, as it already has for the geniculate nerves in knee arthritis. Interventional radiology is poised to contribute to this space with the use of CT guidance to provide safe, fast, and effective targeting of the target nerves for unequivocal diagnostic nerve block and definitive cooled radiofrequency denervation. The authors provide the background of which nerves are targeted for hip and shoulder denervation and the normal CT appearance of these blocks.

Genicular Nerve Ablation Review Using Cooled-Radiofrequency Nerve Ablation

Osteoarthritis (OA) is globally the most prevalent joint disease and causes patients great pain, limited joint mobility, and psychological distress. Short- and long-term therapies like steroid injections and arthroplasty exist, respectively. Joint arthroplasty can effectively treat symptomatic end-stage OA, but most patients do not go through with surgery because they are not qualified, have comorbidities, or do not wish to undergo surgery. As a result, patients can turn to opioid agonists for pain relief, which contributes to the growing opioid epidemic that mars our communities. Cooled radiofrequency ablation (C-RFA) is an effective treatment modality that can alleviate the pain associated with moderate to severe OA, especially in patients who have tried and failed conservative therapy. This review article elucidates the benefits of C-RFA, while also walking through the technical steps to performing the procedure. For patients suffering from debilitating joint OA, especially of the knee, C-RFA is a minimally invasive procedure that ensures pain relief.

Cooled radiofrequency ablation for pain related to Perthes' disease: a novel application

Perthes' disease is a rare paediatric condition involving idiopathic avascular necrosis of the femoral head, leading to degenerative hip joint disease. While joint replacement surgery is considered as the definitive surgical choice of managing degenerative hip disease, alternative methods of pain relief are available, especially for young patients, to defer joint replacement to a later date. One method of reducing pain for 18-24 months is cooled radiofrequency ablation (CRFA). CRFA has been gaining recognition as an effective treatment option for chronic musculoskeletal-related pain in multiple joints. This is the first case report describing the successful use of CRFA in the non-surgical management of Perthes' disease-related osteoarthritic hip pain in a man in his 40s. CRFA treatment led to a reported subjective improvement in pain of 60%-70%, with a documented objective improvement in the Oxford Hip Score from 18 to 40 within 6 weeks of the CRFA procedure.

Cooled Radiofrequency Ablation for Chronic Joint Pain Secondary to Hip and Shoulder Osteoarthritis

Osteoarthritis (OA) of the shoulder and hip is a leading cause of physical disability and mental distress. Traditional nonsurgical management alone is often unable to completely address the associated chronic joint pain. Moreover, a large number of patients are not eligible for joint replacement surgery owing to comorbidities or cost. Radiofrequency ablation (RFA) of articular sensory nerve fibers can disrupt the transmission of nociceptive signals by neurolysis, thereby providing long-term pain relief. A subtype of RFA, cooled RFA (CRFA), utilizes internally cooled electrodes to generate larger ablative zones compared with standard RFA techniques. Given the complex variable innervation of large joints such as the glenohumeral and hip joints, a larger ablative treatment zone, such as that provided by CRFA, is desired to capture a greater number of afferent nociceptive fibers. The suprascapular, axillary, and lateral pectoral nerve articular sensory branches are targeted during CRFA of the glenohumeral joint. The obturator and femoral nerve articular sensory branches are targeted during CRFA of the hip. CRFA is a promising tool in the interventionalist's arsenal for management of OA-related pain and symptoms, particularly in patients who cannot undergo, have long wait times until, or have persistent pain following joint replacement surgery. An invited commentary by Tomasian is available online. ^©RSNA, 2022.

Radiofrequency Ablation of the Trochanteric Branches of the Femoral Nerve for the Treatment of Greater Trochanteric Syndrome

Background

Approximately 10–15% of the population over the age of 60 suffers from hip pain. Greater trochanteric pain syndrome (GTPS) is one of the most common diagnoses in patients with chronic hip pain, includes a number of disorders, and has a broad differential diagnosis. Conservative managements of GTPS, including pharmacologic interventions, physical therapy, chiropractic intervention, acupuncture, and more invasive techniques, such as intra-articular injections, commonly fail to provide patients with sufficient, long-term relief. While radiofrequency ablation (RFA) has been used to treat intra-articular hip pain in the past, there is little evidence for the feasibility of RFA for managing patients with GTPS. This case series builds on previous evidence that cooled radiofrequency ablation (CRF) of the trochanteric branch of the femoral nerve may offer patients with GTPS effective, safe, and lasting pain improvement.

Cases

A series of eight patients with GTPS underwent CRF of the nervus females to the trochanter. CRF procedures were either targeted at the left, right, or bilateral nerves.

Conclusion

This case series provides additional evidence for the safety and effectiveness of CRF of the nervus femoralis to the trochanter for offering long-term pain relief in patients with GTPS. All patients experienced at least two months of relief, with most patients experiencing ongoing relief from the procedure.

A Novel Treatment Approach of Ultrasound-Guided Radiofrequency Ablation of the Greater Trochanteric Sensory Nerve for Recalcitrant Greater Trochanteric Pain Syndrome

This report describes a novel technique for the treatment of recalcitrant greater trochanteric pain syndrome (GPTS) by radiofrequency ablation (RFA) of the greater trochanteric sensory nerve (GTsn). Here, we describe one patient suffering from recalcitrant GTPS treated with RFA of the GTsn in the outpatient pain clinic setting. Over the eight months subsequent to treatment, the patient was monitored for changes in the Numerical Pain Rating (NPR) and Lower Extremity Functional Score (LEFS). The patient demonstrated meaningful symptomatic and functional improvement as measured by both NPR and LEFS. GTsn RFA may be a viable treatment option for recalcitrant GTPS. Larger comparative trials are needed to establish improved results over conventional treatments.

No Association Between Intrauterine Contraceptive Devices and Musculoskeletal Hip Joint Pain

Purpose

To investigate the association between intrauterine device (IUD) use and hip pain, orthopaedic visits for hip pain, and arthroscopic hip surgery.

Methods

This was a retrospective cohort study of patients aged 18-44 years old using either IUDs or subdermal implants for contraception in a large commercial claims database (MarketScan) from 2012 to 2015. All patients had at least 12 months of continuous enrollment both before and after contraceptive placement. Patients with a history of hip pain or surgery were excluded. The primary outcome was new hip pain. Secondary outcomes included visiting an orthopaedic or sports medicine provider for a hip complaint, intra-articular hip injection, and arthroscopic hip surgery. Outcomes were analyzed with Cox proportional-hazard models.

Results

We identified a total of 242,383 patients, including 216,541 (89.3%) with IUDs and 25,842 (10.7%) with subdermal contraceptive implants. In time-to-event analysis, IUDs (vs implants) were not associated with increased risk of new hip pain diagnoses (hazard ratio [HR] 0.95, 95% confidence interval [CI] 0.87-1.03, P = .21). In contrast, both age (P < .001) and region (P < .001) were associated with increased risk of new hip pain. Similar results were seen for the secondary outcomes, including risk of orthopaedic visits for hip complaints (HR 1.06, 95% CI 0.83-1.35, P = .63), intra-articular injections of the hip (HR 0.94, 95% CI 0.63-1.41, P = .77), and hip arthroscopy procedures (HR 1.13, 95% CI 0.53-2.40, P = .75).

Conclusions

In this study, we found no evidence that IUDs were associated with hip pain or surgery.

Level of Evidence

Level III, retrospective cohort.

Hip Ablation Techniques

Radiofrequency ablation (RFA) is still an emergent technique for the management of chronic hip pain. Although the ablation technique for facet articular branches of lumbar and cervical spine was already established, the literature on the targets and technique of needle placement for hip denervation are evolving. This article summarizes the current understanding of the anatomy of the articular branches, sonoanatomy, and the suggested techniques for the RFA of the hip. It also reviews the literature on the clinical studies.

Latest Evidence-Based Application for Radiofrequency Neurotomy (LEARN): Best Practice Guidelines from the American Society of Pain and Neuroscience (ASPN)

Radiofrequency neurotomy (RFN), also known as radiofrequency ablation (RFA), is a common interventional procedure used to treat pain from an innervated structure. RFN has historically been used to treat chronic facet-joint mediated pain. The use of RFN has more recently expanded beyond facet-joint mediated pain to peripherally innervated targets. In addition, there has also been the emergence of different radiofrequency modalities, including pulsed and cooled RFN. The use of RFN has been particularly important where conservative and/or surgical measures have failed to provide pain relief. With the emergence of this therapeutic option and its novel applications, the American Society of Pain and Neuroscience (ASPN) identified the need for formal evidence-based guidance. The authors formed a multidisciplinary work group tasked to examine the latest evidence-based medicine for the various applications of RFN, including cervical, thoracic, lumbar spine; posterior sacroiliac joint pain; hip and knee joints; and occipital neuralgia. Best practice guidelines, evidence and consensus grading were provided for each anatomical target.

Radiofrequency Ablation for Chronic Hip Pain: A Comprehensive, Narrative Review

Chronic hip pain can be treated with physical therapy, oral medications, injections, and, definitively, total hip arthroplasty. Enough patients have contraindications to and refractory pain even after total hip arthroplasty, that there is a need to develop alternative managements for this disabling condition. This article examines the state of hip radiofrequency ablation literature including relevant anatomy, patient selection, and treatment outcomes.

Innervation of the Posterior Hip Capsule: A Cadaveric Study

OBJECTIVE

Recent studies of hip anatomy have turned to the posterior hip capsule to better understand the anatomic location of the posterior capsular sensory branches and identify nerves with potential for neural blockade. Current literature has shown the posterior hip capsule is primarily supplied by branches from the sciatic nerve, nerve to quadratus femoris, and superior gluteal nerve (1, 2). This cadaveric study investigated the gross anatomy of the posterior hip, while also identifying potential targets for hip analgesia, with emphasis on the superior gluteal nerve and nerve to quadratus femoris.

DESIGN

Cadaveric study.

SETTING

UT Health San Antonio Anatomy Lab.

METHODS

In total, 10 total cadavers (18 hips total), were posteriorly dissected identifying nerve to quadratus femoris, superior gluteal nerve, and sciatic nerve. Nerves were labeled with radio-opaque markers. Following the dissections, fluoroscopic images were obtained at sequential angles to identify neural anatomy and help expand anatomic knowledge for interventional pain procedures.

RESULTS

The posterior hip capsule was supplied by the sciatic nerve in 1/16 hips, the nerve to quadratus femoris in 15/18 hips, and the superior gluteal nerve in 6/18 hips.

CONCLUSIONS

The nerve to quadratus femoris reliably innervates the posterior hip joint. Both the sciatic nerve and superior gluteal nerve have small articular branches that may be involved in posterior hip innervation, but this is not seen commonly. The results of this study may elucidate novel therapeutic targets for treatment of chronic refractory hip pain (i.e., the nerve to quadratus femoris).

The expanding role of chronic pain interventions in multimodal perioperative pain management: a narrative review

Surgery is a risk factor for chronic pain and long-term opioid use. As perioperative pain management continues to evolve, treatment modalities traditionally used for chronic pain therapy may provide additional benefit to patients undergoing surgery. Interventions such as radiofrequency ablation, cryoneurolysis, and neuromodulation may potentially be used in conjunction with acute pain procedures such as nerve blocks and multimodal analgesia. Pharmacological agents associated with chronic pain medicine, including gabapentinoids, ketamine, and selective serotonin reuptake inhibitors, may be useful adjuncts in perioperative pain management when indicated. There may also be a role for acupuncture, music therapy, and other integrative medicine therapies. A transitional pain service can help coordinate outpatient care with inpatient perioperative pain management and promote a more personalized and comprehensive approach that can improve postoperative outcomes.

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.

A systematic review and meta-analysis of radiofrequency procedures on innervation to the shoulder joint for relieving chronic pain

BACKGROUND AND OBJECTIVE

Studies have reported relief of chronic shoulder pain with non-ablative pulsed neuromodulatory (pRF) or ablative radiofrequency (aRF) procedures on innervation of the shoulder joint but interpretation of these reports is hampered by inconsistent indications, anatomic targets and follow-up. This systematic review was conducted to synthesize the existing literature on procedures employing pRF or aRF for treating chronic shoulder pain.

DATABASES AND DATA TREATMENT

MEDLINE and other medical literature databases were reviewed up to 31 December 2019 for publications on pRF or aRF procedures on shoulder joint innervation to relieve chronic pain. Data on analgesic and functional outcomes measured at any time point following the interventions were extracted. Existing knowledge on innervation of the shoulder joint with relevance to RF procedures was also synthesized.

RESULTS

In all, 42 publications, 7 randomized controlled trials (RCTs) and 35 observational studies, case series or reports were identified. Thirty-six of these publications were on pRF procedure and 29 of these reported procedures exclusively targeting the suprascapular nerve. A meta-analysis of the seven RCTs evaluating pRF indicated no analgesic benefit or functional improvement with this treatment over conventional medical management. Case series and reports on aRF indicate a potential for analgesic benefit but the quality of this evidence was low.

CONCLUSIONS

RF treatments targeting the sensory innervation of the shoulder joint affected by degenerative conditions have the potential to reduce pain but the current evidence does not suggest analgesic or functional benefit (GRADE certainty of evidence-low). Studies of high methodological quality are required to further investigate the role of these interventions.

SIGNIFICANCE

This is a comprehensive review of literature on pulsed (non-ablative) and ablative radiofrequency (RF) procedures for chronic shoulder pain. The systematic review and meta-analysis of 7 trials found that pulsed RF for chronic shoulder pain provided similar analgesia and functional improvement as conservative medical management at three months after the procedures. The case series and reports on ablative RF for shoulder pain indicate possible analgesic benefit but their quality was low. This review highlights the need for studies of a high quality on ablative RF treatments for chronic shoulder pain.

[Interdisciplinary position paper: the value of radiofrequency denervation in the treatment of chronic pain]

Radiofrequency denervation has been established for many years as an important minimally invasive procedure for the treatment of chronic pain conditions. Positive experiences of many users for various indications are contrasted by a nonuniform evidence. With meticulous patient selection and correct assessment of the indications a longer term reduction of pain, a reduced need for analgesics and an improvement in the quality of life can be achieved. The aim of this interdisciplinary position paper is to present the value of radiofrequency denervation in the treatment of chronic pain. The summarized recommendations of the expert group are based on the available evidence and on the clinical experiences of Austrian centers that frequently implement the procedure. The position paper contains recommendations on patient selection and proven indications. We discribe safety aspects, complications, side effects and contraindications.

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.

Chronic hip pain in adults: Current knowledge and future prospective

Chronic hip pain is distressing to the patient as it not only impairs the daily activities of life but also affects the quality of life. Chronic hip pain is difficult to diagnose as patients often present with associated chronic lumbar spine and/or knee joint pain. Moreover, nonorthopaedic causes may also present as chronic hip pain. The accurate diagnosis of chronic hip pain starts with a detailed history of the patient and thorough knowledge of anatomy of the hip joint. Various physical tests are performed to look for the causes of hip pain and investigations to confirm the diagnosis. Management of chronic hip pain should be mechanistic-based multimodal therapy targeting the pain pathway. This narrative review will describe relevant anatomy, causes, assessment, investigation, and management of chronic hip pain. The focus will be on current evidence-based management of hip osteoarthritis, greater trochanteric pain syndrome, meralgia paresthetica, and piriformis syndrome. Recently, there is emphasis on the role of ultrasound in interventional pain procedures. The use of fluoroscopic-guided radiofrequency in periarticular branches of hip joint has reported to provide pain relief of up to 36 months. However, the current evidence for use of platelet-rich plasma in chronic hip osteoarthritis pain is inconclusive. Further research is required in the management of chronic hip pain regarding comparison of fluoroscopic- and ultrasound-guided procedures, role of platelet-rich plasma, and radiofrequency procedures with long-term follow-up of patients.

Minimally Invasive Therapies for Osteoarthritic Hip Pain: a Comprehensive Review

PURPOSE OF REVIEW

Osteoarthritis (OA) is a highly prevalent cause of chronic hip pain, affecting 27% of adults aged over 45 years and 42% of adults aged over 75 years. Though OA has traditionally been described as a disorder of "wear-and-tear," recent studies have expanded on this understanding to include a possible inflammatory etiology as well, damage to articular cartilage produces debris in the joint that is phagocytosed by synovial cells which leads to inflammation.

RECENT FINDINGS

Patients with OA of the hip frequently have decreased quality of life due to pain and limited mobility though additional comorbidities of diabetes, cardiovascular disease, poor sleep quality, and obesity have been correlated. Initial treatment with conservative medical management can provide effective symptomatic relief. Physical therapy and exercise are important components of a multimodal approach to osteoarthritic hip pain. Patients with persistent pain may benefit from minimally invasive therapeutic approaches prior to consideration of undergoing total hip arthroplasty. The objective of this review is to provide an update of current minimally invasive therapies for the treatment of pain stemming from hip osteoarthritis; these include intra-articular injection of medication, regenerative therapies, and radiofrequency ablation.

A Retrospective Case Series of Pericapsular Nerve Group (PENG) Block for Primary Versus Revision Total Hip Arthroplasty Analgesia

The innervation of the hip joint is complex and it is challenging to provide effective analgesia after hip surgery utilizing any single regional anesthesia technique. The pericapsular nerve group (PENG) block is an interfascial plane block aiming to block articular branches supplied by femoral, obturator, and accessory obturator nerves. In this case series, we compare the efficacy of the PENG block to provide analgesia in primary and revision total hip arthroplasty (THA). The ultrasound-guided PENG block technique is described and post-operative pain scores and opioid requirements are reported. The PENG block was successfully used in primary THA as a solo block, and it may be used in combination with other regional blocks for any hip surgery. The PENG block is an easy regional technique to perform in the supine position with motor-sparing benefits.

Domain Heterogeneity in Radiofrequency Therapies for Pain Relief: A Computational Study with Coupled Models

The objective of the current research work is to study the differences between the predicted ablation volume in homogeneous and heterogeneous models of typical radiofrequency (RF) procedures for pain relief. A three-dimensional computational domain comprising of the realistic anatomy of the target tissue was considered in the present study. A comparative analysis was conducted for three different scenarios: (a) a completely homogeneous domain comprising of only muscle tissue, (b) a heterogeneous domain comprising of nerve and muscle tissues, and (c) a heterogeneous domain comprising of bone, nerve and muscle tissues. Finite-element-based simulations were performed to compute the temperature and electrical field distribution during conventional RF procedures for treating pain, and exemplified here for the continuous case. The predicted results reveal that the consideration of heterogeneity within the computational domain results in distorted electric field distribution and leads to a significant reduction in the attained ablation volume during the continuous RF application for pain relief. The findings of this study could provide first-hand quantitative information to clinical practitioners about the impact of such heterogeneities on the efficacy of RF procedures, thereby assisting them in developing standardized optimal protocols for different cases of interest.

Therapeutic exercise and radiofrequency in the rehabilitation project for hip osteoarthritis pain

BACKGROUND

Severe hip osteoarthritis is responsible for disabling pain and functional impairment of the joint. Although total hip arthroplasty (THA) is a successful treatment, some patients have multiple comorbidities that represent contraindications for THA. Conventional drug therapies are often ineffective or responsible for numerous side effects. For these patients, it is difficult to draw up an acceptable rehabilitation path, as the main limitation is intense pain. New rehabilitation strategies that relieve pain and improve articular function need to be developed. The combination of traditional treatments such as education and therapeutic exercise with innovative, minimally-invasive therapies such as continuous radiofrequency (CRF) appears to reduce hip pain by determining the neurolysis of the joint.

AIM

The aim of our study was to describe the reduction in pain and improvements in joint function when CRF is combined with the therapeutic exercise in rehabilitation of patients with severe hip osteoarthritis.

DESIGN

Case series study.

SETTING

Rehabilitation service outpatients.

POPULATION

Twenty-five patients with severe hip osteoarthritis causing disabling pain and with contraindications to THA, and for whom conventional drug therapies were ineffective or responsible for numerous side effects.

METHODS

The study design included: initial clinical-functional assessment using the Harris Hip Score (HHS), the Numeric Rating Scale (NRS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC); a pre-lesion anaesthetic block; hip neuroablation with CRF; a three-week kinesitherapy protocol (3 sessions per week); two further assessments using the same scales one month (T1) and six months (T2) after CRF.

RESULTS

Improvements at T1 and T2 follow-ups, after CRF (P=0.000) were recorded for articular pain and function. However, results at T2 were worse than those at T1 (P=0.000).

CONCLUSIONS

CRF combined with therapeutic exercise in rehabilitation of severe hip osteoarthritis is an attractive option for significant pain relief as it allows patients to carry out kinesitherapy more easily.

CLINICAL REHABILITATION IMPACT

CRF could represent a valid alternative in the rehabilitation of patients with severe hip osteoarthritis especially when other therapeutic approaches are unworkable.

Review of Knee Joint Innervation: Implications for Diagnostic Blocks and Radiofrequency Ablation

Objective

To determine if commonly used knee radiofrequency ablation (RFA) techniques would be able to completely denervate the knee joint.

Methods

A comprehensive search of the literature on knee joint innervation was conducted using the databases Medline, Embase, and PubMed from inception through February 1, 2019. Google Scholar was also searched. Data on the origin, number of articular branches, course, distribution, and frequency of each nerve innervating the knee joint were extracted from the included studies and compared in order to identify variations.

Results

Twelve studies of anterior knee joint innervation and six studies of posterior knee joint innervation were included. The anterior knee joint was innervated by 10 nerves and further subdivided into two parts (anteromedial and anterolateral) or four quadrants (superomedial, inferomedial, superolateral, and inferolateral) based on innervation patterns; the posterior knee joint was innervated by two or three nerves, most commonly via the popliteal plexus. There is a lack of precise, validated anatomic targets identifiable with fluoroscopy and ultrasound for knee diagnostic blocks and RFA. Only three of the 12 or potentially 13 nerves innervating the knee joint are targeted by commonly used knee RFA techniques.

Conclusions

Commonly used knee RFA techniques would not be able to completely denervate the knee joint. It may not be necessary to capture all of the nerves, but only the nerves mediating a patient’s pain. Further clinical studies are required to validate specific diagnostic blocks and evaluate clinical outcomes using rigorous diagnostic blocks and anatomically specific knee RFA techniques.

Can recent chronic pain techniques help with acute perioperative pain?

PURPOSE OF REVIEW

This article discussed how the knowledge and technique of a few chronic pain procedures benefited the perioperative clinicians in their care of patients receiving specific orthopaedic surgical procedures.

RECENT FINDINGS

Recent emerging interest in hip and knee denervation for chronic pain management secondary to osteoarthritis stimulates publications on the new understanding of hip and knee joint innervation. The improved understanding of the anatomy allows better precision in targeting the articular branches. The procedures for chronic joint pain such as radiofrequency ablation, chemical neurolysis and neuromodulation procedure have recently been applied to the perioperative care in orthopaedic procedures because of the potential long-lasting analgesia, opioid-sparing effect and consequent improvement in physical function and health-related quality of life after surgery.

SUMMARY

Despite the widespread use of regional anaesthesia and multimodal analgesia in the perioperative pain management, more than two-third of the patients reported severe postoperative pain. Therefore, other therapeutic strategies used in chronic pain management such as radiofrequency ablation and neuromodulation have been proposed to optimize acute postsurgical pain. The early experience with those techniques is encouraging, and more studies are required to explore the incorporation of these procedures in the perioperative care.

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.