A pilot cohort study of lumbar facet joint denervation in patients with chronic low-back pain.

INTRODUCTION: Radio-frequency (RF) denervation of the facet joints is a procedure aimed at the nociceptive median branch nerves of the lumbar dorsal rami. Pain signals from the facet joints are carried through these fibres; by ablating these fibres, central signalling can be prevented. This pilot study investigated the clinical effect and feasibility of the procedure at our institution, the Spine Centre of Southern Denmark. METHODS: Patients with at least 50% pain relief after initial medial branch diagnostic blocks were candidates for RF denervation. Patients were divided into two groups: 1) patients with at least 80% pain relief and 2) patients with between 50% and 79% pain relief after diagnostic blocks. Denervation was performed bilaterally on the three lowest facet joints in the lumbar spine. The primary outcome parameter was visual analogue scale (VAS). Follow-up questionnaires were answered after one week and after three, six and 12 months. RESULTS: For the whole sample, we found a mean reduction of 43 VAS points after one week. At three months, we found a mean reduction of 25 points. Six-month data showed a mean 19-point reduction. Twelve-month data showed a mean reduction of 17 points. Group 1 showed superior improvements at all follow-up points and after 12 months, we found a mean VAS reduction of 22 points for this group. CONCLUSIONS: This pilot cohort study found RF denervation of the facet joint to be a promising alternative for patients with chronic low-back pain. The effect persisted at the one-year follow-up; however, the effect diminished over time. FUNDING: The Danish Rheumatism Association, The A.P. Møller Foundation for the Advancement of Medical Science. TRIAL REGISTRATION: The study protocol was approved by the ethical committee of Southern Denmark with registration number S-20160070.

A shortened radiofrequency denervation method for cervical zygapophysial joint pain based on ultrasound localization of the nerves.

OBJECTIVE: Radiofrequency neurotomy is a recognized treatment for cervical zygapophysial joint pain. In several studies, the method has provided complete pain relief in 60-70% of the patients for approximately 9 months. The validated technique has the disadvantage of procedural times of 2-4 hours because several lesions are performed to take into account the variable nerve course. We tested the hypothesis that ultrasound localization of the nerves would enable us to reduce the number of lesions performed, while reaching the benchmark of at least 80% pain relief in 80% of patients with a median duration of 35 weeks, as achieved by a previous investigation using the standard method. INTERVENTIONS: We prospectively studied 15 consecutive patients with diagnosed cervical zygapophysial joint pain. They were treated using a shortened radiofrequency procedure under fluoroscopic control, based on previous ultrasound localization of the joint supplying nerves, with only two thermal lesions performed per nerve. Successful treatment was defined as at least 80% pain relief in the visual analog scale as compared with pretreatment. Follow-up was performed until 12 months after treatment. RESULTS: Of the 15 patients, 14 were successfully treated (93%, 95% confidence interval [CI] 80-100%) with a median time of pain relief of 44 weeks. At 6 and 12 months, 13 (87%, 95% CI 70-100%) and 6 patients (40%, 95% CI 15-65%) reported successful treatment, respectively. The median duration of the procedure was 35 minutes. CONCLUSION: In patients with cervical zygapophysial joint pain, radiofrequency denervation according to a shortened protocol based on ultrasound localization of the nerves reached the benchmark of the standard technique.

A report of 3 soldiers returned to full duty after lumbar radiofrequency facet denervation in a theater of war.

OBJECTIVE: To provide the advanced interventional procedure of zygapophysial joint neurotomy to soldiers meeting the diagnostic criteria in a combat environment and thus reduce medical evacuations of soldiers from a theater of war. DESIGN: Retrospective chart review was performed on three consecutive soldiers who received neuroablation of the lumbar ZP joint. Patients received single MBB with 1 cc of 1% lidocaine at the b/l L3-L5 levels considered diagnostic if >50% analgesia was achieved concordant with duration of anesthetic. SETTING: All procedures were co-performed by the two authors at the Ibn Sina hospital in Baghdad, Iraq over a 3-month period. PATIENTS: Three consecutive patients with >50% pain relief from diagnostic medial branch blocks were treated with radiofrequency ablation of the bilateral L3-L4 medial branch nerves and L5 posterior primary ramus. INTERVENTIONS: Sensory test stimulation at 50 Hz and motor stimulation at 2 Hz were performed at each level. The nerves were then lesioned at 80° Centigrade for 90 seconds after injection of lidocaine and methylprednisolone. OUTCOME MEASURES: Procedure was considered successful if patients were able to wear body armour without significant discomfort (at least 1 hour/day). RESULTS AND CONCLUSIONS: Medical evacuation from Iraq was prevented and all soldiers returned to rigorous combat duties including the wearing of body armour daily. We believe to be the first to report on the use of RF nerve ablation in a war time setting and with this functional outcome.

Radiofrequency denervation of the lumbar zygapophysial joints--targeting the best practice.

OBJECTIVE: Radiofrequency denervation of the zygapophysial (facet) joint is a frequently performed procedure for chronic low back pain. Several studies have shown considerable efficacy of the procedure, but none of the randomized controlled trials performed to date has used anatomically correct placement of radiofrequency cannula parallel to the target nerve. Three main techniques have been utilized for many years: North American, European, and Australian. Each has conceptual and technical limitations. This review analyzes these techniques and proposes a standardized technique of radiofrequency denervation of lumbar zygapophysial joints. DESIGN: Current techniques of radiofrequency neurotomy were analyzed with respect to anatomic and technical accuracy. Step by step guidelines were developed using a combination of previously described techniques along with newly elaborated technical hints and details. CONCLUSION: We believe that the technique using "tunnel vision" with anatomically appropriate cannula placement and use of a large-bore, curved needle with a 10-mm active tip may improve the results of radiofrequency denervation of lumbar zygapophysial joints. Providing a detailed description of an anatomically accurate technique should be of value to those seeking to perform this procedure in a valid manner.

Lumbar zygapophysial (facet) joint radiofrequency denervation success as a function of pain relief during diagnostic medial branch blocks: a multicenter analysis.

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 underwent 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 postprocedure, and global perceived effect (GPE), which considered pain relief, satisfaction and functional improvement. METHODS: Data were garnered at three centers on 262 patients who underwent l-z RF denervation 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 blocks, 56% obtained greater than or equal to 50% relief from RF denervation and 66% had a positive GPE. CONCLUSIONS: Using more stringent pain relief criteria when selecting patients for l-z joint RF denervation is unlikely to improve success rates, and may lead to misdiagnosis and withholding a potentially valuable treatment from good candidates.

A systematic review of therapeutic facet joint interventions in chronic spinal pain.

BACKGROUND: Facet joints are considered to be a common source of chronic spinal pain. Facet joint interventions, including intraarticular injections, medial branch nerve blocks, and neurotomy (radiofrequency and cryoneurolysis) are used to manage chronic facet-mediated spinal pain. A systematic review of therapeutic facet interventions published in January 2005, concluded that facet interventions were variably effective for short-term and long-term relief of facet joint pain. OBJECTIVE: To provide an updated evaluation of the effectiveness of 3 types of facet joint interventions in managing chronic spinal pain. STUDY DESIGN: A systematic review utilizing criteria established by the Agency for Healthcare Research and Quality (AHRQ) for evaluation of randomized and non-randomized trials and the Cochrane Musculoskeletal Review Group for randomized trials. METHODS: Data sources included relevant literature of the English language identified through searches of MEDLINE and EMBASE (November 2004 to December 2006) and manual searches of bibliographies of known primary and review articles within the last 2 years. Results of the analyses were performed for the different modes of facet joint interventions for the cervical, thoracic and lumbar spine, to determine short- and long-term outcome measurements and complications associated with these procedures. OUTCOME MEASURES: The primary outcome measure was pain relief. For intraarticular facet joint injections and medial branch blocks, short-term pain relief was defined as relief lasting less than 6 weeks and long-term relief as 6 weeks or longer. For medial branch blocks, repeated injections at defined intervals provided long-term pain relief. For medial branch radiofrequency neurotomy, short-term pain relief was defined as relief lasting less than 3 months and long-term relief as lasting 3 months or longer. Other outcome measures included functional improvement, improvement of psychological status, and return to work. RESULTS: For cervical intraarticular facet joint injections, the evidence is limited for short- and long-term pain relief. For lumbar intraarticular facet joint injections, the evidence is moderate for short- and long-term pain relief. For cervical, thoracic, and lumbar medial branch nerve blocks with local anesthetics (with or without steroids), the evidence is moderate for short- and long-term pain relief with repeat interventions. The evidence for pain relief with radiofrequency neurotomy of cervical and lumbar medial branch nerves is moderate for short- and long-term pain relief, and indeterminate for thoracic facet neurotomy. CONCLUSION: With intraarticular facet joint injections, the evidence for short- and long-term pain relief is limited for cervical pain and moderate for lumbar pain. For medial branch blocks, the evidence is moderate for short- and long-term pain relief. For medial branch neurotomy, the evidence is moderate for short- and long-term pain relief.

Pulsed radiofrequency treatment of the lumbar medial branch for facet pain: a retrospective analysis.

BACKGROUND: The use of pulsed radiofrequency (PRF) for treatment of the medial branch is controversial. STUDY DESIGN: A retrospective study of the results of PRF treatment of the medial branch in 48 patients with chronic low back pain was carried out. Patients who did not respond were offered treatment with conventional radiofrequency heat lesions. PATIENT MATERIAL: Patients were included who had low back pain and >50% pain relief following a diagnostic medial branch block. The mean age was 53.1 +/- 13.5 years, the mean duration of pain was 11.4 +/- 10.9 years (range 2-50). Nineteen patients had undergone surgery. METHODS: Pain scores on a numeric rating scale of 1-10 were noted before and after the diagnostic nerve block, before the procedure, and at 1-month and 4-month follow-up. PRF was applied for 2 minutes at a setting of 2 x 20 ms/s and 45 V at a minimum of two levels using a 22G electrode with a 5 mm active tip. Heat lesions were made at 80 degrees C for 1 minute. OUTCOME DEFINITION: A successful outcome was defined as a >60% improvement on the numeric rating scale at 4-month follow-up. RESULTS: In 21/29 nonoperated patients and 5/19 operated patients, the outcome was successful. In the unsuccessful patients who were subsequently treated with heat lesions, the success rate was 1/6. CONCLUSION: The setup of our study does not permit a comparison with the results of continuous radiofrequency (CRF) for the same procedure, other than the detection of an obvious trend. When comparing our results with various studies on CRF of the medial branch such a trend could not be found. Based on these retrospective data, prospective and randomized trials, for example, radiofrequency vs PRF are justified.

A critical review of the evidence for the use of zygapophysial injections and radiofrequency denervation in the treatment of low back pain.

BACKGROUND CONTEXT: Lumbar zygapophysial joints are currently believed to be a cause of axial low back pain. Once this diagnosis is made, decisions about when to institute a particular intervention and which treatment to offer is regionally and specialty dependent. PURPOSE: To perform a critical review of prior published studies assessing the use of interventional treatment options for the treatment of lumbar zygapophysial joint syndrome. STUDY DESIGN: Evidence-based medicine analysis of current literature. METHODS: A database search of Medline (PubMed, Ovid and MDConsult), Embase and the Cochrane database was conducted. The keywords used were low back pain, lumbar zygapophysial joint, lumbar facet joint, radiofrequency denervation, medial branch block, and intraarticular injection. After identifying all relevant literature, each article was reviewed. Data from the following categories were compiled: inclusion criteria, randomization of subjects, total number of subjects involved at enrollment and at final analysis. statistical analysis used, intervention performed, outcome measures, follow-up intervals and results. Guidelines described by the Agency for Health Care Policy and Research were then applied to these data. RESULTS: This review determined that the evidence for the treatment of lumbar zygapophysial joint syndrome with intraarticular injections should be rated as level III (moderate) to IV (limited) evidence, whereas that for radiofrequency denervation is at a level III. CONCLUSIONS: Current studies fail to give more than sparse evidence to support the use of interventional techniques in the treatment of lumbar zygapophysial joint-mediated low back pain. This review emphasizes the need for larger, prospective, randomized controlled trials with uniform inclusion and exclusion criteria, standardized treatment, uniform outcome measures and an adequate duration of follow-up period so that definitive recommendations for the treatment of lumbar zygapophysial joint-mediated pain can be made.

Ablation of bone, cartilage, and facet joint capsule using Ho:YAG laser.

OBJECTIVE: The objective of this study was to determine of the efficiency of holmium:YAG laser for bone ablation, compared to cartilage and soft tissue of the intervertebral foramen of the lumbosacral spine. BACKGROUND DATA: The holmium:YAG (Ho:YAG) laser has been used for ablation of bulging or prolapsed discs and also has the potential for decompression of the nerve root when there is narrowing of the foraminae (foraminoplasty). It is proposed that laser ablation of bone and ligament of the intervertebral foramen for nerve root decompression using the Ho:YAG laser is able to produce sufficient bone ablation without inducing significant thermal necrosis in surrounding tissues due to its short absorption length, which could result in significant clinical advantages. MATERIALS AND METHODS: Experiments were performed on samples of laminar bone, facet joint capsule, and cartilage for quantitative and qualitative determination of the effect of Ho:YAG ablation on tissue mass loss using a range of pulse energies from 0.5 to 1.5 J/P at 15 pulses/sec. RESULTS: The results showed a significant linear correlation between the mass loss and pulse energy, and between the mass loss and radiant exposure. Electron microscopy and histology showed that the Ho:YAG ablation resulted in a very sharp and clear border with little charring. Applying 0.01 k.J of total energy at two different settings (1.5 J/p, high power, and 0.5 J/p, low power) at 15 pulses/sec, the cross-sectional area/mm(2) of the ablated bone was measured, using light microscopy and the Scion Image analysis program. The ablated areas were 2.28 +/- 0.87 and 1.16 +/- 0.43 mm(2) at high and low power, respectively (p = 0.008).