Branch Of Median Nerve Research Articles

Treatment of chronic axial back pain with 60-day percutaneous medial branch PNS: Primary end point results from a prospective, multicenter study.

BackgroundThe objective of this prospective, multicenter study is to characterize responses to percutaneous medial branch peripheral nerve stimulation (PNS) to determine if results from earlier, smaller single‐center studies and reports were generalizable when performed at a larger number and wider variety of centers in patients recalcitrant to nonsurgical treatments.Materials & MethodsParticipants with chronic axial low back pain (LBP) were implanted with percutaneous PNS leads targeting the lumbar medial branch nerves for up to 60 days, after which the leads were removed. Participants were followed long‐term for 12 months after the 2‐month PNS treatment. Data collection is complete for visits through end of treatment with PNS (primary end point) and 6 months after lead removal (8 months after start of treatment), with some participant follow‐up visits thereafter in progress.ResultsClinically and statistically significant reductions in pain intensity, disability, and pain interference were reported by a majority of participants. Seventy‐three percent of participants were successes for the primary end point, reporting clinically significant (≥30%) reductions in back pain intensity after the 2‐month percutaneous PNS treatment (n = 54/74). Whereas prospective follow‐up is ongoing, among those who had already completed the long‐term follow‐up visits (n = 51), reductions in pain intensity, disability, and pain interference were sustained in a majority of participants through 14 months after the start of treatment.ConclusionGiven the minimally invasive, nondestructive nature of percutaneous PNS and the significant benefits experienced by participants who were recalcitrant to nonsurgical treatments, percutaneous PNS may provide a promising first‐line neurostimulation treatment option for patients with chronic axial back pain.

Chronic Low Back Pain: The Therapeutic Benefits of Diagnostic Medial Branch Nerve Blocks

Chronic low back pain (CLBP) is an extremely prevalent disease, whose etiology is often multifactorial. Facet joint arthropathy is one of the most common causes of CLBP. Facet joints are innervated by the medial branches of the primary and adjacent level dorsal rami and are, therefore, key potential targets for the symptomatic management of CLBP. A lumbar medial branch nerve block (MBB) procedure is often used to assist in the diagnosis of facet mediated CLBP. For unclear reasons, some patients experience protracted relief of CLBP after diagnostic MBBs alone. To describe the phenomenon of protracted relief of CLBP after diagnostic MBBs and search for predictors of this response. A retrospective chart review of patients who underwent MBB procedures by a single practitioner, over a 2 year period, was conducted. All patients were seen at the Montefiore Multidisciplinary Pain Program, Bronx, NY. Data from follow up visits was used to categorize patient's response to MBBs as having no relief (NR), transient relief (TR) or protracted relief (PR). Patient demographics and characteristics were collected, and a multivariate analysis investigating associations with PR was conducted. 146 patients met inclusion criteria. 41 patients (28%) had NR, 54 (37%) had TR, and 51 (35%) had PR. CLBP symptom duration of < 6 months (P = 0.013) and unilateral back pain symptoms (P = 0.0253) were significantly associated with PR after MBB. This is a retrospective study with a relatively small sample size conducted on patients belonging to a single practitioner. Outcomes were based largely on subjective patient satisfaction scores. In select patients, MBB may produce protracted relief of CLBP symptoms. The authors present distinct hypotheses which may help explain the therapeutic effects of diagnostic MBB procedures.

Modified Carpal Tunnel Release: A New Approach to Minimizing Pillar Pain.

Pillar pain is a frequent postoperative complication of carpal tunnel release (CTR). The precise definition of pillar pain is lacking, but most authors describe it as diffuse aching pain and tenderness in the thenar and hypothenar area. The etiology of pillar pain is unclear. However, the most prevalent theory is the neurogenic theory, which attributes the pain to the damage of small nerve branches of palmar cutaneous branches of median nerve after surgical incision, with resulting entrapment of the nerves in the scar tissue at the incision site. We postulated that a main source of pillar pain is sensory neuromas along the incision site.In this article, we describe a simple modification of the standard CTR technique with intent to decrease neuroma formation and thus minimizing pillar pain. This is a retrospective study comparing the incidence and duration of pillar pain between patients who underwent standard CTR (SCTR, n = 53) versus the minimizing pillar pain CTR technique (n = 55). Based on duration of pillar pain, the groups were placed into 3 subgroups (<3, 3-6, and >6 months). Presence and duration of pillar pain in each group were recorded along with return to work (RTW), complications, and patient satisfaction. The SCTR group had a total of 17 patients with pillar pain (32.1%), 5 of which resolved within 3 months, 7 within 3 to 6 months, and 5 in more than 6 months. The group that underwent the minimizing pillar pain technique had a total of 4 patients with pillar pain (7.2%). Three resolved within 3 months, 1 resolved within 3 to 6 months, and there were no patients with pillar pain lasting more than 6 months. Average RTW time for minimization of pillar pain CTR (MPPCTR) was 34.9 days. Average RTW time for SCTR was 54.8 days. Satisfaction was higher among patients who underwent surgery with MPPCTR. Based on these results, we concluded that MPPCTR compared with SCTR had equal complication rate, however, significantly lower incidence and duration of pillar pain, higher rate of satisfaction, and earlier RTW.

Lumbar Spondylolisthesis Progression: What is the Effect of Lumbar Medial Branch Nerve Radiofrequency Ablation on Lumbar Spondylolisthesis Progression? A Single-Center, Observational Study.

BackgroundRadiofrequency ablation (RFA) is a denervation therapy commonly performed for pain of facet etiology. Degenerative spondylolisthesis, a malalignment of the spinal vertebrae, may be a co-existing condition contributing to pain; yet the effect of RFA on advancing listhesis is unknown. To the extent that denervating RFA may weaken paraspinal muscles that provide stability to the spine, the therapy can potentially contribute to progressive spinal instability.MethodsSingle-center, prospective, observational pilot study in an interventional pain practice to test the hypothesis that RFA of painful facets in the setting of spondylolisthesis may contribute to advancement of further degenerative spondylolisthesis. Fifteen participants with pre-existing degenerative Grade I or Grade II spondylolisthesis and coexisting axial lumbar pain underwent lumbar RFA encompassing spondylolisthesis level and followed with post-RFA imaging at 12 months and beyond to measure percent change in spondylolisthesis.ResultsThe primary outcome was the percent advancement of spondylolisthesis per year measured on post-RFA lateral lumbar spine imaging compared with non-intervention inferred baseline advancement of 2% per very limited observational studies. Among the 15 participants enrolled, 14 completed the study (median age 66; 64.3% women; median BMI 33.5; mean follow-up time 23.9 months). The mean advancement of spondylolisthesis per year after RFA was 1.30% (95% CI −0.14 to 2.78%), with 9/14 below 1.25%.ConclusionAmong patients with lumbar pain originating from facets in the setting of degenerative spondylolisthesis who underwent lumbar RFA, the observed advancement of spondylolisthesis is clinically similar to the estimated maximum baseline of 2% per year change. The study findings did not find a destabilizing effect of lumbar RFA in advancing spondylolisthesis in this patient population.

Percutaneous Peripheral Nerve Stimulation of the Medial Branch Nerves for the Treatment of Chronic Axial Back Pain in Patients After Radiofrequency Ablation.

ObjectiveLumbar radiofrequency ablation is a commonly used intervention for chronic back pain. However, the pain typically returns, and though retreatment may be successful, the procedure involves destruction of the medial branch nerves, which denervates the multifidus. Repeated procedures typically have diminishing returns, which can lead to opioid use, surgery, or implantation of permanent neuromodulation systems. The objective of this report is to demonstrate the potential use of percutaneous peripheral nerve stimulation (PNS) as a minimally invasive, nondestructive, motor-sparing alternative to repeat radiofrequency ablation and more invasive surgical procedures.DesignProspective, multicenter trial.MethodsIndividuals with a return of chronic axial pain after radiofrequency ablation underwent implantation of percutaneous PNS leads targeting the medial branch nerves. Stimulation was delivered for up to 60 days, after which the leads were removed. Participants were followed up to 5 months after the start of PNS. Outcomes included pain intensity, disability, and pain interference.ResultsHighly clinically significant (≥50%) reductions in average pain intensity were reported by a majority of participants (67%, n = 10/15) after 2 months with PNS, and a majority experienced clinically significant improvements in functional outcomes, as measured by disability (87%, n = 13/15) and pain interference (80%, n = 12/15). Five months after PNS, 93% (n = 14/15) reported clinically meaningful improvement in one or more outcome measures, and a majority experienced clinically meaningful improvements in all three outcomes (i.e., pain intensity, disability, and pain interference).ConclusionsPercutaneous PNS has the potential to shift the pain management paradigm by providing an effective, nondestructive, motor-sparing neuromodulation treatment.

Current Perspectives on Neurostimulation for the Management of Chronic Low Back Pain: A Narrative Review.

Neurostimulation techniques for the treatment of chronic low back pain (LBP) have been rapidly evolving; however, questions remain as to which modalities provide the most efficacious and durable treatment for intractable axial symptoms. Modalities of spinal cord stimulation, such as traditional low-frequency paresthesia based, high-density or high dose (HD), burst, 10-kHz high-frequency therapy, closed-loop, and differential target multiplexed, have been limitedly studied to determine their efficacy for the treatment of axial LBP. In addition, stimulation methods that target regions other than the spinal cord, such as medial branch nerve stimulation of the multifidus muscles and the dorsal root ganglion may also be viable treatment options. Here, current scientific evidence behind neurostimulation techniques have been reviewed with a focus on the management of chronic axial LBP.

Management of Flexor Pollicis Longus Injury - Experience in BSMMU

Anatomic consideration: Flexor pollicis longus (FPL) tendon arises from volar aspect of middle third of radial shaft and from the lateral aspect of interosseous membrane. The anterior interosseous branch of median nerve innervates the muscle in the proximal/mid forearm. Blood supply is predominantly from radial artery.&#x0D; Abstract Purpose: The purpose of this study was to evaluate the results of repair and one stage reconstruction of FPL injury and to find out complications and rupture rate and effectiveness of repair and reconstruction.&#x0D; Method: This retrospective review was carried out in Bangabandhu Sheikh Mujib Medical University from January 2015 to December 2018. 30 consecutive patients were enrolled in the study. 4 strands core suture with simple circumferential suture were used for repair and reconstruction. Tendon transfer was done in few cases. Power grip, active and passive range of motion, American Society for Surgery of the Hand criteria and Buck-Gramcko criteria were used for outcome assessment.&#x0D; Results: Out of 30 patients, 20 (67%) were male and 10 (33%) were female. Mean age was 30 years. Mean follow up period was 1.5 years. All cases were due to various type of cut injuries. In subjective assessment 40% patients achieved excellent, 50% good, 10% fair results. Our rupture rate was 0%. Mean power grip, pinch grip strength of index and key pinch strength were 87.5%, 68.18% and 86.66% respectively from contralateral normal hand. Active range of motion of IP joint was 64.28% of normal side.&#x0D; Conclusions: Use of 4 strands core sutures and early active motion give good to excellent results in 90% cases of repair, reconstruction and tendon transfer in FPL injuries with 0% rupture rate&#x0D; J Shaheed Suhrawardy Med Coll, December 2020, Vol.12(1); 20-26

Surgical denervation of the thumb CMC joint: anatomy, technique

Surgical denervation of the thumb carpometacarpal (CMC) joint is a theoretical surgical option for thumb CMC arthritis. Some authors have described the nerve branches of thumb CMC joint. We present the innervation of the thumb CMC joint (thenar – recurrent – branch of median nerve, palmar branch of median nerve, superficial branch of radial nerve, lateral cutaneous nerve of forearm, deep branch of ulnar nerve) and the surgical techniques to achieve optimal denervation of this joint. While the results have been disappointing, this technique may be combined with conservative surgical procedures (synovectomy, ligament reconstruction) and it allows more invasive surgery in the future if necessary.

Comparing the Efficacy of Combined Treatment with Medial Branch Block and Facet Joint Injection in Axial Low Back Pain.

Introduction Medial branch nerve block (MBB) and facet joint injections (FJIs) can be used to manage axial low back pain. Although there have been studies comparing the MBB and FJI effects, a few studies have compared the therapeutic effects of both interventions combined with each separate intervention. This study aimed to compare the pain relief effect of MBB, FJI, and combined treatment with MBB and FJI in patients with axial low back pain. Methods We conducted a retrospective review of patients with axial low back pain who had chart records of the Numeric Rating Scale (NRS) and Oswestry Disability Index (ODI) scores measured before treatment and within 6 weeks after treatment. The proportion of patients with successful responses (>30%) was calculated and is presented with Wald confidence intervals. Results We included 66 patients (33, 17, and 16 patients in the MBB, FJI, and combined treatment with MBB and FJI groups). All the patient groups showed significant posttreatment improvements in the NRS [(proportion >30% decrease: MBB 24.2% (9.6–38.9), FJI 29.4% (7.8–51.1), and MBB + FJI 25.0% (3.8–46.2)] scores and the ODI [proportion >30% decrease: MBB 39.4% (22.7–56.1), FJI 23.5% (3.4–43.7), and MBB + FJI 37.5% (13.8–61.2)] scores. Furthermore, there was no significant among-group difference in the ODI and NRS scores. Conclusion MBB, FJI, and combined treatment with MBB and FJI can reduce axial low back pain and improve secondary functional degradation. Although combined treatment with MBB and FJI required a longer intervention time, it did not have a pain relief effect superior to that of MBB or FJI alone.

Anatomic thermochromic tissue-mimicking phantom of the lumbar spine for pre-clinical evaluation of MR-guided focused ultrasound (MRgFUS) ablation of the facet joint

Objective To develop a thermochromic tissue-mimicking phantom (TTMP) with an embedded 3D-printed bone mimic of the lumbar spine to evaluate MRgFUS ablation of the facet joint and medial branch nerve. Materials and methods Multiple 3D-printed materials were selected and characterized by measurements of speed of sound and linear acoustic attenuation coefficient using a through-transmission technique. A 3D model of the lumbar spine was segmented from a de-identified CT scan, and 3D printed. The 3D-printed spine was embedded within a TTMP with thermochromic ink color change setpoint at 60 °C. Multiple high energy sonications were targeted to the facet joints and medial branch nerve anatomical location using an ExAblate MRgFUS system connected to a 3T MR scanner. The phantom was dissected to assess sonication targets and the surrounding structures for color change as compared to the expected region of ablation on MR-thermometry. Results The measured sound attenuation coefficient and speed of sound of gypsum was 240 Np/m-MHz and 2471 m/s, which is the closest to published values for cortical bone. Following sonication, dissection of the TTMP revealed good concordance between the regions of color change within the phantom and expected areas of ablation on MR-thermometry. No heat deposition was observed in critical areas, including the spinal canal and nerve roots from either color change or MRI. Conclusion Ablated regions in the TTMP correlated well with expected ablations based on MR-thermometry. These findings demonstrate the utility of an anatomic spine phantom in evaluating MRgFUS sonication for facet joint and medial branch nerve ablations.

Tolerability and Feasibility of X-ray Guided Non-Invasive Ablation of the Medial Branch Nerve with Focused Ultrasound: Preliminary Proof of Concept in a Pre-clinical Model

Four to six million patients a year in the United States suffer from chronic pain caused by facet joint degeneration. Thermal ablation of the affected facet joint's sensory nerve using radiofrequency electrodes is the therapeutic standard of care. High-intensity focused ultrasound (HIFU) is a novel technology enabling image-guided non-invasive thermal ablation of tissue. Six pigs underwent fluoroscopy-guided HIFU of the medial branch nerve and were followed up for 1 wk (two pigs), 1 mo (two pigs) and 3 mo (two pigs). At the end of each follow-up period, the animals were sacrificed, and targeted tissue was excised and evaluated with computed tomography scans as well as by macro- and micropathology. No significant adverse events were recorded during the procedure or follow-up period. All targets were successfully ablated. X-Ray-guided HIFU is a feasible and promising alternative to radiofrequency ablation of the lumbar facet joint sensory nerve.

Predicting Treatment Success with Facet Syndrome: An Algorithm to Predict Lumbar Radiofrequency Ablation Responders in a Military Population.

Radiofrequency ablation (RFA) of the medial branch nerve is a commonly performed procedure for patients with facet syndrome. RFA has previously been demonstrated to provide long-term functional improvement in approximately 50% of patients, including those who had significant pain relief after diagnostic medial branch block. We sought to identify factors associated with success of RFA for facet pain. Active-duty military patients who underwent lumbar RFA (L3, L4, and L5 levels) over a 3-year period were analyzed. Defense and Veterans Pain Rating Scale (DVPRS) and Oswestry Disability Index (ODI) scores were assessed the day of procedure and at the 2-month and 6-month follow-up. These data were analyzed to identify associations between patient demographics, pain, and functional status and patients' improvement after RFA, with a primary outcome of ODI improvement and a secondary outcome of pain reduction. Higher levels of starting functional impairment (starting ODI scores of 42.9 vs. 37.5; P = 0.0304) were associated with a greater likelihood of improvement in functional status 6 months after RFA, and higher starting pain scores (DVPRS pain scores of 6.1 vs. 5.1; P < 0.0001) were associated with a higher likelihood that pain scores would improve 6 months after RFA. A multivariate logistic regression was then used to develop a scoring system to predict improvement after RFA. The scoring system generated a C-statistic of 0.764, with starting ODI, pain scores, and both gender and smoking history as independent variables. This algorithm compares favorably to that of diagnostic medial branch block in terms of prediction accuracy (C-statistic of 0.764 vs. 0.57), suggesting that its use may improve patient selection in patients who undergo RFA for facet syndrome.

Medial Branch Blocks for Diagnosis of Facet Joint Pain Etiology and Use in Chronic Pain Litigation.

A commonly disputed medicolegal issue is the documentation of the location, degree, and anatomical source of an injured plaintiff’s ongoing pain, particularly when the painful region is in or near the spine, and when the symptoms have arisen as result of a relatively low speed traffic crash. The purpose of our paper is to provide health and legal practitioners with strategies to identify the source of cervical pain and to aid triers of fact (decision makers) in reaching better informed conclusions. We review the medical evidence for the applications and reliability of cervical medial branch nerve blocks as an indication of painful spinal facets. We also present legal precedents for the legal admissibility of the results of such diagnostic testing as evidence of chronic spine pain after a traffic crash. Part of the reason for the dispute is the subjective nature of pain, and the fact that medical documentation of pain complaints relies primarily on the history given by the patient. A condition that can be documented objectively is chronic cervical spine facet joint pain, as demonstrated by medial branch block (injection). The diagnostic accuracy of medial branch blocks has been extensively described in the scientific medical literature, and evidence of facet blocks to objectively document chronic post-traumatic neck pain has been accepted as scientifically reliable in courts and tribunals in the USA, Canada and the United Kingdom. We conclude that there is convincing scientific medical evidence that the results of cervical facet blocks provide reliable objective evidence of chronic post-traumatic spine pain, suitable for presentation to an adjudicative decision maker.

Thoracic Zygapophysial Joint Thermal Neurotomy: A Cohort Revealing Additional Outcomes by Specific Joint Groupings.

Thoracic spinal pain is common, and patients with this type of pain have limited therapeutic options. The cohort in this study received diagnostic intra-articular zygapophysial joint injections leading to thermal neurotomy to the medial branch nerves to demonstrate improved pain as well as physical and psychological function. A consecutive cohort from 2012 to 2018 with retrospective analysis of prospectively gathered data. A private multidisciplinary pain clinic with referrals from primary care. Forty-six complete data sets from 39 patients were found using a pre-procedure and 3-month post-procedure questionnaire. Further follow-up results were found for the dual primary outcomes of duration of ≥50% relief using a numeric rating scale (NRS) for the entire group. The group was then divided into three subgroups of T1/2-T3/4, T4/5-T8/9, and T9/10-T12/L1. Success rates of 63% for ≥3months of ≥50% relief and 46% for ≥6months of ≥50% relief were found, for an average duration of 7.8 months. Group mean change in the NRS was 6.7, decreasing to 4.3 (P<0.0001). For the first time, there are data showing that the three groups of T1/2-T3/4, T4/5-T8/9, and T9/10-T12/L1 responded equally. Secondary outcomes of physical and psychological function using the Functional Rating Index (FRI) and the Depression Anxiety Stress Scale (DASS) all showed significant improvements with small to moderate effect sizes and with all achieving >36% improvement in scores. This cohort demonstrates that there is a pragmatic diagnostic and therapeutic option available for patients with thoracic zygapophysial joint pain that can achieve 50-100% of pain relief in 63% of patients with improved physical and psychological function.

Percutaneous endoscopic transforaminal and interlaminar lumbar discectomy for cranially migrated disc hernia

Objective. To evaluate clinical outcomes, safety, and technical peculiarities of percutaneous endoscopic transforaminal and interlaminar removal of the lumber spine cranially migrated disc hernias. Material and Methods. In 2015–2018, percutaneous endoscopic transforaminal and interlaminar removal of cranially migrated hernias of the lumbar spine was performed in 53 patients (23 men and 30 women): 2 (3.8 %) at L2–L3 level, 13 (24.5 %) at L3–L4, 18 (34.0 %) at L4–L5, and 20 (37.7 %) at L5–S1. The age of patients ranged from 25 to 76 years and averaged 43.4 ± 11.6 years. Transforaminal approach was performed at the L4–L5 level and higher (62.3 % of cases), and interlaminar approach – at the L5–S1 level (37.7 %). Based on MRI, hernias with cranial migration were divided into zones: zone I – hernias with migration to the lower edge of the superjacent vertebra pedicle – 21 (39.6 %) patients; and zone II – hernias with migration above this border – 32 (60.4 %). Results were evaluated using ODI, VAS, and the McNab scale. Statistical analysis of VAS indicators (leg and back pain) and ODI scores before and after surgery was performed using the R and Microsoft Excel 2007 software. Results. Data collection was carried out using patient questionnaires at in-person examination, telephone interviews and electronic communications. Follow-up data of different terms were monitored in all patients. In one case (when mastering this technology), at the second stage, microdiscectomy was performed at the L4–L5 level for a residual hernia fragment in migration zone II, and in another case, a conversion into microdiscectomy was performed at L3–L4 level with a hernia in zone II due to lack of venous bleeding control in a patient receiving anticoagulants. In other patients, the mean VAS scores of preoperative radicular and axial pain decreased from 7.5 ± 1.4 and 3.8 ± 1.2 to 1.4 ± 1.2 and 3.5 ± 1.3, respectively, on the next day, to 1.7 ± 1.4 and 3.2 ± 1.1 in 1 month, to 1.5 ± 1.3 and 2.8 ± 1.4 in 6 months, to 1.6 ± 1.2 and 2.0 ± 1.3 in 12 months, and to 1.6 ± 1.2 and 2.0 ± 1.3 in 24 months after surgery. In the long-term follow-up period, no radicular leg pain was observed in any patient. According to the McNab scale, up to 6 months treatment results were assessed as excellent by 19 (35.8 %) patients, and as good – by 32 (60.3 %). In the case of lumbar pain in the long term period, blockade of facet joints and radiofrequency ablation of the medial nerve branch were performed. Relapse of hernias and instability of the operated spinal segment were not revealed. The average ODI score improved from 66.4 ± 7.2 to 20.5 ± 3.2 in 1 month, to 13.6 ± 2.1 in 6 months, to 12.4 ± 2.3 in 12 months, and to 12.4 ± 2.3 in 24 months after surgery. Conclusion. Percutaneous endoscopic transforaminal and interlaminar discectomy for cranially migrated lumbar disc hernia, while adhering the surgical technique target and exclusion criteria, is a safe and effective method, avoids excessive resection of the bone-ligamentous structures of the spine, can prevent iatrogenic instability of the spinal motion segment, and promotes early postoperative activation and recovery of the patient. Cranially migrated disc henias have a low probability of recurrence.

Two-Needle Technique for Lumbar Radiofrequency Medial Branch Denervation: A Technical Note

Background: Radiofrequency ablation (RFA) of the medial branches of the dorsal rami has been reported to relieve facet joint–related back pain for 6 months to 1 year in 60% of patients. Although providing benefit in a significant proportion of patients, there remains a group of patients who do not experience any pain relief from RFA or experience only benefit from the ablation for a short period. Failure of RFA has been attributed to technical failure of coagulating the nerve or coagulation of a minimal section of the nerve, allowing for early reinnervation. Increasing the success rate and duration of relief may require techniques that increase the likelihood of successful nerve ablation over a relevant distance by maximizing lesion size. Objectives: The aim of this technical note is to detail a modification to the current commonly used lumbar medial branch radiofrequency (RF) denervation approach to increase lesion size. Study Design: This is a technical report describing a novel two-needle approach to lumbar RF medial branch denervation. Setting: Large private interventional pain management institute. Methods: A dual needle placement of two 10-mm active tip RF cannulas separated by 6 mm is used to optimally contact the superior articular process (SAP) from its ventral to dorsal borders, which encompasses the anticipated course of the medial branch nerves. Results: The described technique creates a lesion that we estimate to be 11.0-mm wide and 11.6-mm long along the course of the medial branch adjacent to the SAP ensuring adequate coverage and treatment. Limitations: This report does not encompass a systematic evaluation of the clinical safety and efficacy of the two-needle RFA approach. Future studies will have to assess the longterm efficacy and safety of the approach. Conclusions: The detailed two-needle approach to lumbar RF medial branch denervation appears to be promising in terms of projected treatment success by coagulating a large volume of tissue, in a cost- and time-efficient manner. Key words: Radiofrequency ablation, RFA, lumbar, medial branch, facet joint, pain, rhizotomy

Cervical Dystonia Refractory to Botulinum Toxin Responding to Radiofrequency Ablation: A Case Report

A 62-year-old male diagnosed with cervical dystonia (CD) and chronic right-sided neck pain presented to the Pain Clinic after his pain and CD symptoms failed to resolve with botulinum toxin therapy. During clinical examination, right C3-C4 and C4-C5 facet arthropathy was suspected. After two sets of diagnostic right cervical, C3, C4, and C5 medial branch blocks provided >80% pain relief; cervical radiofrequency ablation (CRFA) was performed. Post CRFA, the patient was followed for 12 months. Till the last follow-up, he was not only experiencing 90% pain relief, but also had significant improvement in his CD symptoms to the point that he no longer needed botulinum toxin and other CD-related therapy. This report suggests that large-scale research is required to postulate whether CD patients, whose symptoms are refractory to botulinum toxin, should be routinely screened for cervical facet arthropathy. This is the first reported case of improvement in CD symptoms with CRFA. This effect could be explained by the fact that certain deep cervical muscles, which are affected in CD, are innervated by medial branch nerves.

In vivo measurements of medial branch nerve depth and adjacent osseous structures for ablation of facet-related back pain: Predictors for patient candidacy

In vivo measurements of medial branch nerve depth and adjacent osseous structures for ablation of facet-related back pain: Predictors for patient candidacy

In vivo measurements of medial branch nerve depth and adjacent osseous structures for ablation of facet-related back pain: Predictors for patient candidacy

BackgroundMedial branch (MB) targeting during RF ablation for facetogenic back pain is usually performed with flouroscopic guidance yet no specific measurements on the target depth have been published. In order to understand candidacy for other potential ablation methods, we sought to determine the actual MB depth and measurements of adjacent osseous structures. MethodsCT scans without contrast of the lumbar spine performed in the supine position were retrospectively analyzed in 100 patients. Axial slices less than or equal to 2.5 mm with sagittal and coronal reformations were evaluated. The following distances were measured bilaterally at the L2-L5 levels: The depth from the skin to the MB nerve (anatomic target for RF ablation) at a 15° angulation, the smallest width of the pedicle, and the length, height and width of the transverse process. Age, gender, weight, height, and BMI were correlated with the above measurements. ResultsThe average distance and 95% CI from skin-to-MB in mm at a 15°angle to the skin increased as the lumbar level increased measuring 64.4 (62.4–66.5) at L2, 72.0 (69.7–74.3) at L3, 79.2 (76.9–81.6) at L4, and 79.1 (76.7–81.5) at L5. The average thickness of the pedicles also increased as the lumbar level increased measuring 9.2 mm at L2 and 16.1 mm at L5. Body weight, lumbar level, and female gender were associated with increased MB depth. Taller stature was associated with more superficial MB depth. We eliminated mild interaction effects between height, weight, and gender by substituting BMI for height and weight without affecting r2. Linear regression revealed the following equation: MB Depth (mm) = 2.2*BMI + 4.9*lumbar vertebral level + 3.6 (if female) – 5.4, which fit the data well (P<0.001, r2 = 0.60). ConclusionsOur results demonstrate that the MB resides 107 mm or less in depth when measured at a 15° angulation from the skin in > 95% of patients and the distance increases as the lumbar level increases.

A Review of Peripheral Nerve Stimulation Techniques Targeting the Medial Branches of the Lumbar Dorsal Rami in the Treatment of Chronic Low Back Pain.

The lumbar medial branch nerve has historically been a focus for ablative techniques in the treatment of chronic low back pain (CLBP) of facetogenic origin. Recent developments in the field of neuromodulation have been employed to target these nerves for analgesia and/or functional restoration in broader populations of CLBP patients. The objective of this article was to provide an introductory review of procedural techniques and devices employed for peripheral nerve stimulation (PNS) of the lumbar medial branch of the dorsal ramus for the treatment of CLBP. A literature search via PubMed.gov was performed through September 2019 with key words focusing on peripheral nerve stimulation for chronic low back pain. This was refined to include only those articles that focused specifically on stimulation of the lumbar medial branch of the dorsal ramus. References within selected articles and unpublished data currently in the peer review process were also utilized. Ninety articles from PubMed.gov were obtained. Two approaches to PNS of the medial branch of the dorsal ramus were identified. Our review of the current literature regarding techniques for neuromodulation of the medial branch of the dorsal ramus revealed two dominant methods: a temporarily implanted percutaneous coiled-lead approach and a permanently implanted system. The two techniques share some similarities, such as targeting the medial branch of the dorsal ramus, and also have some differences, such as indwelling time, stimulation parameters, duration of treatment, image guidance, and degrees of invasiveness, but they are both demonstrating promising results in clinical trials.