Branch Of Median Nerve Research Articles

Clinical-applied anatomy of the carpal tunnel regarding mini-invasive carpal tunnel release.

Carpal tunnel release is a widely performed procedure. Despite a high success rate, iatrogenic neurovascular injuries can occur which lead to a painful and unsatisfying outcome. This study conducted a detailed examination of the anatomy of the carpal tunnel and the proximity of neurovascular structures that are particularly susceptible to injury, especially in the context of minimally invasive carpal tunnel release procedures. The anatomy of the carpal tunnel of 104 wrists of 52 body donors was examined. The precise anatomical location and the presence of variations were recorded for the median nerve, ulnar nerve, ulnar artery and Berrettini branch. The distance between the median nerve, the ulnar artery, the ulnar nerve, and the Berrettini branch was measured in a proximo-distal and radio-ulnar direction in relation to the distal ulnar end of the carpal tunnel. The authors identified four main dangerous anatomical situations. (1) A proximal separation of the Long-Finger/Ring-Finger branch of the median nerve together with a narrow safe-zone; (2) an ulnar take-off of the recurrent muscle branch of the median nerve with a close radio-ulnar distance to the distal ulnar end of carpal tunnel; (3) an ulnar arterial arch lying close to the transverse carpal ligament; and (4) a proximal Berrettini branch also lying close to the latter. All situations are illustrated by photographs. Additionally, the authors present a sonographic carpal tunnel assessment protocol in order to reduce the risk of injury of any neurovascular structure in the proximity of the carpal tunnel. Certain patients may inherently face an increased risk of neurovascular injuries during minimally invasive carpal tunnel releases due to their anatomical variations. Four potentially risky scenarios were clearly illustrated. Consequently, one may consider conducting a preoperative ultrasound assessment of neurovascular structures at risk, when endoscopic or ultrasound-guided tunnel release are planned. In high-risk patients, open surgery should be preferred. II.

Clinical application of ultrasound in thoracic medial branch block and thoracic cooled-radiofrequency ablation: Case report and literature review

Introduction: Radiofrequency ablation is a procedure used to alleviate pain by destroying nerves with by radiofrequency-generated heat. Traditionally, radiofrequency ablation is preceded by diagnostic medial branch block injections, both guided by fluoroscopy. Fluoroscopic visualization of the superolateral aspect of the thoracic transverse process, where thoracic medial branch nerves occur, can be challenging due to anatomical complexities, especially in obese patients. We present a novel technique in which ultrasound was utilized in conjunction with fluoroscopy to perform medial branch block and radiofrequency ablation of the thoracic medial branch nerves. Case Report: First, two diagnostic thoracic medial branch nerve blocks were performed under ultrasound guidance. For the subsequent radiofrequency ablation, spinal needles were first advanced under ultrasound guidance to the target thoracic medial branch nerves. The position of those spinal needles was then used to guide the placement of cooled radiofrequency ablation probes using fluoroscopy. The patient reported 100% pain relief following the procedures. Discussion: We found that the addition of ultrasound allowed us to overcome the challenge of visualizing the superolateral aspect of thoracic transverse process under fluoroscopy alone. Direct ultrasound visualization allowed us to accurately and safely perform a thoracic medial branch block and radiofrequency ablation in a patient with poor fluoroscopic anatomy, as demonstrated by the patient’s complete pain relief after both medial branch block and radiofrequency ablation. We also theorize that our novel technique allows the provider to directly visualize the pleura, which could reduce the risk of severe pneumothorax associated with thoracic medial branch block and cooled radiofrequency ablation.

Targeted Muscle Reinnervation in the Upper Arm: A Functional Anatomical Study

BackgroundThe aim of this study was to accurately locate the neural fascicle controlling hand movement in the upper arm, to enhance expression of motor intention after targeted muscle reinnervation. MethodsThe right sides of the median, ulnar and radial nerves were dissected from distal to proximal in 6 fresh cadaver specimens. The sectional location and diameter of the functional fascicle were measured at 10 and 20 cm below the acromion. The diameter of the main muscle branches of muscle reinnervation target muscles was measured. ResultsThe median nerve branch of finger and wrist flexion was mainly located between the 9 and 12 o’clock positions in the plane 10 and 20 cm below the acromion, where the diameter of the nerve fascicle was 2.07 and 2.04 mm, respectively. The ulnar nerve branch of finger and wrist flexion was mainly located between the 8 and 12 o’clock positions, with a diameter of respectively 1.80 and 1.99 mm. The radial branch of finger and wrist extension was mainly located between the 10 and 2 o’clock positions in the plane 10 cm below the acromion and between 6 and 12 o’clock in the plane 20 cm below the acromion, with a diameter of respectively 2.57 and 3.03 mm. ConclusionsThe nerve fascicles innervating the flexor and extensor fingers were distributed in relatively constant regions of the median, ulnar and radial nerve trunks, and their diameters closely matched the muscle branches of the target muscle.

Innervation of thumb carpometacarpal joint: implications for diagnostic block and denervation procedures

IntroductionOsteoarthritis (OA) of the thumb carpometacarpal (CMC) joint is a common disorder that negatively impacts hand function. Denervation of the thumb CMC joint has emerged as a viable treatment option....

Effectiveness and cost-effectiveness of radiofrequency denervation versus placebo for chronic and moderate to severe low back pain: study protocol for the RADICAL randomised controlled trial

IntroductionLow back pain (LBP) is the leading global cause of disability. Patients with moderate to severe LBP who respond positively to a diagnostic medial nerve branch block can be offered...

Multifidus atrophy and/or dysfunction following lumbar radiofrequency ablation: A systematic review.

Lumbar medial branch nerve radiofrequency ablation (LRFA) is an interventional procedure used to treat chronic lumbar facet joint pain. Because the medial branch nerves also innervate the multifidus muscle, it has been proposed that LRFA may pose a risk of multifidus atrophy and/or dysfunction. However, the quality and level of evidence to answer this clinical question have not been established. Therefore, this review aimed to systematically appraise the literature to discern whether the prevailing evidence substantiates the hypothesis in question. A systematic review compliant with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed to evaluate the quality and level of evidence of studies reporting functional and/or structural changes in the multifidus muscle following LRFA. Only five cohort studies met inclusion criteria. Two studies assessed changes in multifidus function following LRFA with confirmed denervation at electromyography and significant reduction in multifidus shear modulus with ultrasound shear wave elastography. Of the four studies that evaluated changes in multifidus structure with magnetic resonance imaging following LRFA, two demonstrated a decrease in cross-sectional area or an increase in fat infiltration, one demonstrated no change, and one revealed an apparent increase. Given the destructive nature attributed to LRFA, some degree of multifidus atrophy and/or dysfunction may be plausible, albeit with a very low certainty that relies on a restricted body of literature of modest quality and with a presence of high bias. There is a paucity of studies discussing the potential association between LRFA and multifidus atrophy and/or dysfunction. In light of the shortage of high-quality studies and the absence of standardized protocols to assess both changes in the structure and function of the multifidus subsequent to LRFA, there is a pressing need for more prospective studies with a high methodological rigor to comprehensively address and answer this enduring debate in clinical practice.

Upper Extremity Nerve Transfers for Treatment of Nerve Injury After Cervical Spine Surgery: A Single-Center Retrospective Review.

Nerve transfers to restore or augment function after spinal cord injury is an expanding field. There is a paucity of information, however, on the use of nerve transfers for patients having undergone spine surgery. The incidence of neurologic deficit after spine surgery is rare but extremely debilitating. The purpose of this study was to describe the functional benefit after upper extremity nerve transfers in the setting of nerve injury after cervical spine surgery. A single-center retrospective review of all patients who underwent nerve transfers after cervical spine surgery was completed. Patient demographics, injury features, spine surgery procedure, nerve conduction and electromyography study results, time to referral to nerve surgeon, time to surgery, surgical technique and number of nerve transfers performed, complications, postoperative muscle testing, and subjective outcomes were reviewed. Fourteen nerve transfers were performed in 6 patients after cervical spine surgery. Nerve transfer procedures consisted of a transfer between a median nerve branch of flexor digitorum superficialis into a biceps nerve branch, an ulnar nerve branch of flexor carpi ulnaris into a brachialis nerve branch, a radial nerve branch of triceps muscle into the axillary nerve, and the anterior interosseous nerve into the ulnar motor nerve. Average patient age was 55 years; all patients were male and underwent surgery on their left upper extremity. Average referral time was 7 months, average time to nerve transfer was 9 months, and average follow-up was 21 months. Average preoperative muscle grading was 0.9 of 5, and average postoperative muscle grading was 4.1 of 5 ( P < 0.00001). Upper extremity peripheral nerve transfers can significantly help patients regain muscle function from deficits secondary to cervical spine procedures. The morbidity of the nerve transfers is minimal with measurable improvements in muscle function.

Cryoneurolysis versus radiofrequency ablation outcome on pain experience in chronic low back pain (COPE): a single-blinded randomised controlled trial

ObjectiveA comparison of cryoneurolysis or radio frequency (RF) with placebo in patients with facetogenic chronic low back pain (LBP) for patient global impression of change (PGIC), pain intensity, function and...

Transfer of Motor Fascicle From the Ulnar Nerve to the Axillary Nerve by Posterior Access. New Approach.

We describe a new technique of transferring the motor branch ulnar nerve (UN) to the axillary nerve (AN) by posterior approach. Three patients with C5, C6, and C7 brachial plexus injury were operated. By supraclavicular approach, the spinal accessory was transferred to the suprascapular nerve. By posterior approach in the arm, the AN was identified within the quadrilateral space, and the UN was identified medially with intrafascicular dissection of a motor fascicle, which is lifted to 4 cm in length and transferred to AN. By medial approach, a motor branch from the median nerve is transferred to the biceps nerve. At a follow-up minimum of 10 months, the maximum abduction was 160 and the minimum 90 degrees. This technique, neurotization of the AN with fascicles of the UN, spinal accessory to suprascapular nerve, and median nerve branch to biceps nerve are indicated in C5-C7 avulsion when there is no radial nerve available. Level IV.

Fluoroscopy-guided high-intensity focused ultrasound ablation of the lumbar medial branch nerves: dose escalation study and comparison with radiofrequency ablation in a porcine model

BackgroundRadiofrequency ablation (RFA) is a common method for alleviating chronic back pain by targeting and ablating of facet joint sensory nerves. High-intensity focused ultrasound (HIFU) is an emerging, non-invasive, image-guided...

Impact of temperature on the magnitude and duration of relief after lumbar facets medial branch nerves radiofrequency ablation: a randomized double-blinded study

IntroductionThere are numerous studies appraising the variables that may influence the clinical outcomes after lumbar thermal radiofrequency ablation (RFA). Expanding the lesion size may increase the likelihood of capturing the...

Abstract No. 273 Cooled versus Standard Radiofrequency Ablation of the Medial Branch Nerves in the Management of Chronic Facetogenic Low Back Pain

Abstract No. 273 Cooled versus Standard Radiofrequency Ablation of the Medial Branch Nerves in the Management of Chronic Facetogenic Low Back Pain

Rare Median Nerve and Digital Nerve Tumor Resection and Distal Nerve Transfers: A Report of 2 Cases.

We present 2 cases of median nerve reconstruction using distal nerve transfers after resection of unusual benign median nerve tumors. Critical sensation was restored in case 1 by transferring the fourth common digital nerve to first web digital nerves. Thumb opposition was regained by transferring the abductor digiti minimi ulnar motor nerve branch to the recurrent median motor nerve branch. Critical sensation was restored in case 2 by transferring the long finger ulnar digital nerve to the index finger radial digital nerve. Distal nerve transfers, even with short grafts, are reliable median nerve deficit treatments, sparing the need for larger autologous nerve grafts and late tendon opponensplasties.

Predicting spatio-temporal radiofrequency ablation temperature using deep neural networks

Radiofrequency ablation (RFA) of the medial branch nerve is a widely used therapeutic intervention for facet joint pain. However, denervation of the multifidus muscle is an inevitable consequence of RFA. New ablation techniques with the potential to prevent muscle denervation can be designed using computational simulations. However, depending on the complexity of the model, they could be computationally expensive. As an alternative approach, deep neural networks (DNNs) can be used to predict tissue temperature during RFA procedure. The objective of this paper is to predict the tissue spatial and temporal temperature distributions during RFA using DNNs. First, finite element (FE) models with a range of distances between the probes were run to obtain the temperature readings. The measured temperatures were then used to train the DNNs that predict the spatio-temporal temperature distribution within the tissue. Finally, a separate data obtained from FE simulations were used to test the efficacy of the network. The results presented in this paper demonstrate that the network can achieve an error rate as low as 0.05%, accompanied by a 92% reduction in time compared to FE simulations. The approach proposed in this study will play a major role in the design of new RFA treatments for facet joint pain.

End-on versus parallel radiofrequency lesioning for neurotomy of the cervical medial branch nerves: a study protocol of a prospective, randomized, double-blind clinical trial: the “EndPaRL” study

BackgroundCervical facet joint disease is a common source of neck pain and its prevalence increases with aging. Conservative multimodal management options (e.g., strengthening of neck muscles, non-steroidal anti-inflammatory medications, massage, and thermal modalities) often fail to relieve pain. Cervical medial branch nerve (CMBN) radiofrequency neurotomy (RFN) is an effective minimally invasive technique for treating chronic neck pain secondary to facet joint disease. An end-on approach for this procedure has been proposed that may be technically easier and require less time while reducing post-procedural discomfort. The protocol presented here is for a study that aims to compare the efficacy of a new end-on approach using multi-tined cannulae, against the conventional parallel technique that employs straight cannulae for RFN of the CMBN in patients with chronic neck pain due to cervical facet joint disease.MethodsA multicentre randomized, non-inferior, active comparator-controlled trial will be conducted with two parallel groups and blinding of participants and outcome assessor. The study will include 72 adults with chronic neck pain secondary to facet joint disease who are candidates for RFA of the CMBN. Participants will be randomized to either the conventional parallel or the end-on approach in a 1:1 ratio. The intensity of pain and pain-related domains (function, quality of life, sleep, adverse effects of the interventions, analgesic intake) will be measured at 1, 3, 6, and 12 months after the procedure.DiscussionNeck pain secondary to cervical facet joint disease is prevalent and RFA of the CMBN is a validated treatment for relieving it. The conventional parallel technique can be technically challenging, and it can be associated with adverse effects while the newer end-on approach has the potential of being a simpler technique with less adverse effects. This trial will be the first non-inferiority study to compare the clinical efficacy of the end-on approach against the conventional parallel approach for RFN of CMBN in patients with chronic neck pain due to cervical facet joint disease.Trial registrationClinicalTrials.gov NCT05818774. Registered on April 20, 2023.

Does medial branch radiofrequency neurotomy accelerate degenerative lumbar spondylolisthesis compared to natural progression? A cross-sectional cohort study

BackgroundLumbar radiofrequency neurotomy (LRFN) effectively treats lumbar zygapophyseal joint pain by coagulating medial branch nerves (MBNs) carrying nociceptive signals. MBNs also innervate deep paraspinal muscles. There is a paucity of literature on whether LRFN accelerates the progression of vertebral displacement in patients with degenerative lumbar spondylolisthesis (DLS). ObjectiveCompare the rate of spondylolisthesis progression in adults with DLS who underwent LRFN to the 2% annual rate of progression expected by natural history. DesignCross-sectional cohort study. MethodsConsecutive patients with pre-existing DLS who underwent LRFN for zygapophyseal joint-mediated low back pain were identified. Patient demographics, LRFN procedure details, and radiographic images confirming Meyerding Grade (I-II) spondylolisthesis were collected from electronic medical records. The quantitative magnitude of spondylolisthesis progression and the annualized rate were calculated from pre-and post-LRFN radiographs. Data were analyzed using Wilcoxon signed-rank tests and a linear regression model. Results152 patients (mean age 65.9 ± 12.3 years; 59.2% female) met eligibility criteria and were included in the analyses. Average time to radiographic follow-up was 35.6 ± 24.7 months post-LRFN. The average spondylolisthesis progression rate of 1.63 ± 2.91% per year calculated for the LRFN cohort was significantly lower than the 2% annual rate of progression associated with natural history (p < 0.001). None of the included covariates, such as age, BMI, LRFN laterality, number of levels denervated, or history of prior lumbar spinal surgery, were significantly associated with the average annual rate of progression. ConclusionsOur results suggest that spondylolisthesis progression rate is no different or worse than the expected natural progression rate in patients with pre-existing DLS who have undergone LRFN.

Anatomical considerations of US-guided carpal tunnel release in daily clinical practice.

Carpal tunnel syndrome is the most frequent compression neuropathy with an incidence of one to three subjects per thousand. As specific anatomical variations might lead to unintended damage during surgical interventions, we present a review to elucidate the anatomical variability of the carpal tunnel region with important considerations for daily clinical practice: several variants of the median nerve branches in and around the transverse carpal ligament are typical and must - similarly to the variant courses of the median artery, which may be found eccentric ulnar to the median nerve - be taken into account in any interventional therapy at the carpal tunnel. Unintended interference in these structures might lead to heavy arterial bleeding and, in consequence, even underperfusion of segments of the median nerve or, if neural structures such as variant nerve branches are impaired or even cut, severe pain-syndromes with a profound impact on the quality of life. This knowledge is thus crucial for outcome- and safety-optimization of different surgical procedures at the volar aspect of the wrist and surgical therapy of the carpal tunnel syndrome e.g., US-guided carpal tunnel release, as injury might result in dysfunction and/or pain on wrist motion or direct impact in the region concerned. For most variations, anatomical and surgical descriptions vary, as official classifications are still lacking.

Proximal forearm nerve branching patterns: an anatomical study and its clinical significance.

The aim of this study was to add to the understanding of nerve branching patterns in the proximal forearm and consider optimal nerve transfer options to address the various injuries that affect the function of the upper extremity. Eleven upper-extremity cadaveric specimens were dissected to expose the radial, median, and ulnar nerves in the proximal forearm. The site of origin of nerve branches from the major nerves was assessed, with measurements made in reference to the lateral epicondyle for the radial nerve branches and the medial epicondyle for the median and ulnar nerve branches. The distances to where these branches entered their respective muscles (muscle entry point) were assessed using the same landmarks. To plan a transfer, the length of the nerve branches was then calculated as the difference from the apparent origin from the main nerve trunk to the location where the nerve entered the muscle. Importantly, the nerve branch origin was established as the location of obvious separation from the main nerve trunk without additional fascicular dissection from the major nerve trunk. The number of branches was determined, and the diameter for each branch was measured using a Vernier caliper. The radial nerve branch to the extensor carpi radialis brevis (ECRB) muscle had an average length of 50.7 mm and average diameter of 1.6 mm. The mean medial and lateral lengths of the radial branches to the supinator muscle were found to be 22.2 mm (diameter 1.4 mm) and 15.3 mm (diameter 1.3 mm), respectively. The anterior interosseous nerve (AIN) branch of the median nerve was found 67.8 mm distal to the medial epicondyle with a diameter of 2.3 mm. The flexor carpi ulnaris (FCU) muscle innervation from the ulnar nerve was provided by 3 or 4 branches in most specimens. The second and third of these branches were the longest, with means of 30.5 mm (diameter 1.4 mm) and 30.7 mm (diameter 1.3 mm), respectively. While there is variability of the nerve branching pattern in the proximal forearm between specimens, the authors provide evidence of commonalities (branching patterns and distances) that can facilitate planning for upper-extremity nerve reconstructions. Importantly, all measurements are provided with reference to easily identified bony landmarks and to their muscle entry points to aid operative decision-making. These data complement the growing practice of nerve transfers in the upper extremity for a variety of pathologies.

ID: 206983 Retrospective Review of Real-World Outcomes Following 60-Day PNS of the Cervical Medial Branch Nerves

Axial neck pain is a prevalent and often debilitating pain condition with conventional treatment options that commonly lack efficacy or are neurodestructive (e.g., radiofrequency ablation). Sixty-day percutaneous peripheral nerve stimulation (PNS) has emerged as a potential non-destructive treatment for axial neck pain that targets efferent fibers in the cervical medial branch nerves to secondarily produce comfortable, cycling tension in core cervical musculature (e.g., multifidus). The present work is a retrospective review of outcomes from patients receiving 60-day PNS treatment targeting the cervical medial branch nerves in routine clinical practice.

ID: 205115 Comparison of Pain Relief and Radiographic Multifidus Changes With Radiofrequency Ablation Versus Peripheral Nerve Stimulation

Multifidus muscle (MM) atrophy is present in nearly 80% of patients with chronic low back pain (CLBP). Functionally, the multifidi work as postural muscles and are difficult to strengthen in this context. The relative size of the MM also relates to the ratio of crucial core muscles and is significant as it predicts injury in athletes. Radiofrequency ablation (RFA) of the medial branch nerves has become common practice in the treatment of CLBP despite its neuro-destructive effects, with statistically significant atrophy exhibited 24 weeks post-procedure when compared to controls. No studies have sought to compare the effects of RFA or temporary PNS of the medial branch nerves on pain scores and the size of multifidus muscle when used for the same clinical diagnoses.