Peripheral Nerve Radiofrequency Neurotomy

[Thermal radiofrequency of the medial genicular nerves in chronic pain related to degenerative meniscopathy. A clinical case]

Persistent knee pain in patients around the fifth decade of life is a frequent cause of attention in rehabilitation consultations. The most common cause of diagnosis is knee osteoarthritis, considering the existence of different degrees seen in simple radiographies. The advanced degrees present joint space reduction, osteophytosis and subchondral sclerosis; however, in the initial degrees, the findings are more subtle and sometimes nonexistent for conventional radiology. Clinical ultrasound has partly come to fill this «diagnostic gap», making it possible to detect meniscal extrusions and small osteophytes as signs of incipient osteoarthritis and to relate them as triggers of pain. In clinical practice we find a group of patients who, with little or no radiological alterations, present persistent and severe pain with medial predominance in most cases. These, until the appearance of the current evidence, were subsidiaries of meniscectomies. At this moment, when meniscectomies are not recommended, it is necessary to find a treatment for those cases in which conservative and non-ablative interventional treatment has failed. In this context, the possibility of using radiofrequency arises. Its use is widespread in the case of tricompartmental and advanced osteoarthritis. However, little data is available on its usefulness in cases of medial meniscal extrusion. It seems that thermal radiofrequency has greater effects than pulsed radiofrequency. We present a clinical case where thermal radiofrequency of the medial genicular nerves of the knee is proposed as a therapeutic alternative for chronic pain secondary to medial meniscal extrusion associated with incipient knee osteoarthritis, with the result of a decrease in pain (VAS 8 before treatment, VAS 1 after one year), subjective improvement of 80% and gait capacity.

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.

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.

Validation of a new protocol for ultrasound-guided genicular nerve radiofrequency ablation with accurate anatomical targets: cadaveric study

INTRODUCTION

Ultrasound (US)-guided radiofrequency ablation (RFA) of genicular nerves (GNs) is increasingly performed to manage chronic knee pain. The anatomical foundations supporting the choice of original targets for US-guided GN-RFA have been thoroughly improved by recent anatomical studies. Therefore, this study aimed to provide a new protocol with revised anatomical targets for US-guided GN-RFA and to assess their accuracy in a cadaveric model.

MATERIALS AND METHODS

Fourteen fresh-frozen cadaveric knees were used. After a pilot study with 4 knees, five consistent nerves were targeted in the other 10 knees with revised anatomical landmarks: superior medial genicular nerve (SMGN), superior lateral genicular nerve (SLGN), inferior medial genicular nerve (IMGN), recurrent fibular nerve (RFN) and the infrapatellar branch of the saphenous nerve (IPBSN). For each nerve, the lumen of radiofrequency (RF) cannula was prefilled with non-diffusible black paint, and then the cannula was inserted at the target site under US guidance. After US verification of correct placement, the stylet was introduced in the cannula to create a limited black mark on the tissues at the top of the active tip. Anatomical dissection was performed to assess for accuracy.

RESULTS

The proportion of nerves directly found in contact with the black mark was 7/10, 8/10, 10/10 and 9/10 for the SMGN, SLGN, IMGN and RFN, respectively. The proportions of nerve captured by the theoretical largest monopolar RF lesions were 100% for the SMGN, IMGN and RFN, and IPBSN and 95% for SLGN. The mean distances from the center of the black mark to the targeted nerve were 2.1±2.2 mm, 1.0±1.4 mm, 0.75±1.1 mm and 2.4±4.5 mm for the SMGN, SLGN, IMGN and RFN, respectively.

CONCLUSION

US-guided GN-RFA with revised anatomical targets resulted in accurate capture of the five targeted nerves. This protocol provides precise sensory denervation of a larger panel of nerves, targeting those whose constancy regarding anatomical location has been clearly demonstrated. It is expected to improve the clinical outcomes.

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.

Accuracy of fluoroscopic-guided genicular nerve blockade: a need for revisiting anatomical landmarks

BACKGROUND AND OBJECTIVES

Genicular nerve blockade (GNB) and radiofrequency ablation (RFA) have recently emerged as treatment options for patients with chronic knee pain. However, an increasing number of anatomical studies and systematic reviews concluded that the anatomical basis for needle placement was unclear, incomplete and somewhat inaccurate. This study was designed to assess the accuracy of updated anatomical landmarks for fluoroscopy-guided blockade of the consistent genicular nerves in a cadaveric model.

METHODS

Based on a comprehensive review of recent anatomical studies and prior dissection of 21 fresh cadaver knees, we defined bony landmarks with high likelihood of successful ablation of the five consistent genicular nerves (GN). We tested the accuracy of GNBs using the above-stated anatomical landmarks in 10 intact fresh cadaveric knees. Needle placement was guided by fluoroscopy and 0.5 mL of 0.1% methylene blue was injected at the site of each nerve. The knees were subsequently dissected to assess the accuracy of the injections. If the nerve was dyed with blue ink, the placement was considered accurate.

RESULTS

The accuracy of our injections was 100% for the superior medial genicular nerve, inferior medial GN, infrapatellar branch of saphenous nerve and recurrent fibular nerve. The superior lateral GN was dyed in 90% of specimens.

CONCLUSION

This study provides physicians with precise anatomical landmarks for the five consistent GN for fluoroscopic-guided GNB. Our revised technique, which targets more nerves with increased accuracy, could potentially lead to improved therapeutic benefits on chronic knee pain.

Management of chronic pain in Ehlers-Danlos syndrome: Two case reports and a review of literature

RATIONALE

Ehlers-Danlos syndromes (EDSs) are a heterogeneous group of heritable connective tissue disorders involving defective collagen synthesis. Patients with EDS are prone for chronic myofascial pain, apart from other comorbidities. Although the initial pathology is commonly nociceptive, progression of EDS leads to neuropathies and central sensitization of pain signals. Overall, approximately 90% or more EDS patients suffer from chronic pain. There are no existing guidelines to manage chronic pain in EDS patients. In this article, we illustrate 2 case reports of EDS patients with chronic pain and review the relevant literature regarding the pathological considerations and management of chronic pain in EDS.

PATIENT CONCERNS

Our first patient had worsening multiple joint pains despite treatment with medications and a recent diagnosis of EDS-type 3. The second patient had a complicated history including longstanding EDS and multiple previous surgeries. She was referred due to concern about complex regional pain syndrome (CRPS) in her upper extremity.

DIAGNOSES

For the first patient, apart from chronic pain due to her EDS, her history also revealed that she suffered from kinesiophobia. For the second patient, a detailed clinical assessment revealed no signs of CRPS but instead a generalized worsening of EDS symptoms.

INTERVENTIONS

Both patients were evaluated by the multidisciplinary team consisting of a pain physician, nurse, pain psychologist, and a kinesiologist. Their treatment involved optimization of daily medications, participation in pain self-management sessions that included cognitive behavioral therapy, graded exercises, coping, and relaxation strategies.

OUTCOMES

Both patients demonstrated significantly better pain control and achieved overall improvement in daily living.

LESSONS

EDS is a complex illness with a multitude of symptoms. As in our patients, EDS patients also suffer from panic and anxiety disorders that increase the burden of pain. Apart from optimization of medications, EDS patients are best managed by a multidisciplinary approach that includes pain education and life style changes. The caution that they are resistant to local anesthetics is unwarranted. Appropriate pain interventions in selected patients may have a role to decrease pain intensity.