The surgical anatomy of lumbar medial branch neurotomy (facet denervation)
ABSTRACT To demonstrate the validity of placing electrodes parallel to the target nerve in lumbar radiofrequency neurotomy.
Previous data on the anatomy of the lumbar dorsal rami were reviewed and a demonstration cadaver was prepared. Under direct vision, electrodes were placed on, and parallel to, the L4 medial branch and the L5 dorsal ramus. Photographs were taken to record the placement, and radiographs were taken to illustrate the orientation and location of the electrode in relation to bony landmarks.
In order to lie in contact with, and parallel to, the target nerve, electrodes need to be inserted obliquely from below, so that their active tip crosses the neck of the superior articular process. At typical lumbar levels, the tip should lie opposite the middle two quarters of the superior articular process. At the L5 level, it should lie opposite the middle and posterior thirds of the S1 superior articular process.
If electrodes are placed parallel to the target nerve, the lesions made can be expected to encompass the target nerves. If electrodes are placed perpendicular to the nerve, the nerve may escape coagulation, or be only partially coagulated. Placing the electrode parallel to the nerve has a demonstrated anatomical basis, and has been vindicated clinically. Other techniques lack such a basis, and have not been vindicated clinically. Suboptimal techniques may underlie suboptimal outcomes from lumbar medial branch neurotomy.
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ABSTRACT: In order to perform standardized diagnostic and operative techniques the knowledge of the anatomical setup is essential. The main goal of our study was to determine the position of the lumbar dorsal rami of the spinal nerve at the level of the articular process, as well as the position of the surrounding structures. Plastinated slices with 1.5 mm thickness are produced out of five non-pathologic vertebral columns. Subsequently the slices were digitalized and processed anatomically and topographically. The gained data of digitalization offered in the next step the possibility to determine the localization of the spinal nerve and its medial branch as well as to build an anatomical three-dimensional computer model of the region. The plastinated slices produced by E12-technique showed intact and unimpaired anatomical structures and highly transparent tissue. This base was used for the analysis and measurement of structural episodes and for the three-dimensional reconstruction of a lumbar moving segment. The constructed 3D-model displays the morphology of the region in the same quality as the cadaver specimen. Based on our anatomic data, the dorsal ramus of the spinal nerve passes very closely to the neck of the superior articular process at the level of the cranial border of the transverse process. Anatomic characteristics should be kept in mind when denervation techniques of the zygapophyseal joints are performed, thereby reducing the risk of injury to the dorsal ramus.MATERIALE PLASTICE 01/2015; 52(1):75-78. · 0.46 Impact Factor
Article: Clinical Studies[Show abstract] [Hide abstract]
ABSTRACT: Lumbar zygapophysial (facet) joint radiofrequency denervation success as a function of pain relief during diagnostic medial branch blocks: a multicenter analysis Abstract BACKGROUND CONTEXT: The publication of several recent studies showing minimal benefit for radiofrequency (RF) lumbar zygapophysial (l-z) joint denervation have led many investigators to reevaluate selection criteria. One controversial explanation for these findings is that the most commonly used cutoff value for selecting patients for l-z (facet) joint RF denervation, greater than 50% pain relief after diagnostic blocks, is too low and hence responsible for the high failure rate. PURPOSE: To compare l-z joint RF denervation success rates between the conventional greater than or equal to 50% pain relief threshold and the more stringently proposed greater than or equal to 80% cutoff for diagnostic medial branch blocks (MBB). STUDY DESIGN/SETTING: Multicenter, retrospective clinical data analysis. PATIENT SAMPLE: Two hundred and sixty-two patients with chronic low back pain who under-went l-z RF denervation at three pain clinics. OUTCOME MEASURES: Outcome measures were greater than 50% pain relief based on visual analog scale or numerical pain rating score after RF denervation persisting at least 6 months post-procedure, and global perceived effect (GPE), which considered pain relief, satisfaction and func-tional improvement. METHODS: Data were garnered at three centers on 262 patients who underwent l-z RF denerva-tion after obtaining greater than or equal to 50% pain relief after diagnostic MBB. Subjects were separated into those who received partial (greater than or equal to 50% but less than 80%) and near-complete (greater than or equal to 80%) pain relief from the MBB. Outcomes between groups were compared with multivariate analysis after controlling for 14 demographic and clinical variables. RESULTS: One hundred and forty-five patients obtained greater than or equal to 50% but less than 80% pain relief after diagnostic MBB, and 117 patients obtained greater than or equal to 80% relief. In the greater than or equal to 50% group, success rates were 52% and 67% based on pain relief and GPE, respectively. Among patients who experienced greater than 80% relief from diagnostic The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of theThe Spine Journal 01/2008; · 2.80 Impact Factor
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ABSTRACT: Objective Low back pain (LBP) is a highly prevalent condition and one of the leading causes of lost productivity and health-care costs. The objective of this review is to discuss the role of interventional pain procedures and evidence of their effectiveness in treatment of chronic LBP.Methods This is a narrative review examining published studies on interventional procedures for LBP. The rationales, indications, technique, evidence, and complications for the interventional procedures are discussed.ResultsInterventional pain procedures are used extensively in diagnosis and treatment of chronic pain. LBP is multifactorial, and while significant progress has been made in understanding its pathophysiology, this has not resulted in a proportional improvement of functional outcomes. For certain procedures, such as spinal cord stimulation, medical branch blocks and radiofrequency ablations, and epidural steroid injections for radiculopathy, safety, efficacy, and cost-effectiveness in treating LBP have been well studied. For others, such as interventions for discogenic pain, treatment successes have been modest at best.Conclusions Implementation of interventional pain procedures in the treatment framework of LBP has resulted in improvement of pain intensity in at least the short and medium terms, but equivocal results have been observed in functional improvement.Neuromodulation 10/2014; 17(S2). DOI:10.1111/ner.12250 · 1.79 Impact Factor