Randomized trial of radiofrequency lumbar facet denervation for chronic low back pain

Are Invasive Procedures Effective for Chronic Pain? A Systematic Review

OBJECTIVE

To assess the evidence for the safety and efficacy of invasive procedures for reducing chronic pain and improving function and health-related quality of life compared with sham (placebo) procedures.

DESIGN

Systematic review with meta-analysis.

METHODS

Studies were identified by searching multiple electronic databases, examining reference lists, and communicating with experts. Randomized controlled trials comparing invasive procedures with identical but otherwise sham procedures for chronic pain conditions were selected. Three authors independently extracted and described study characteristics and assessed Cochrane risk of bias. Two subsets of data on back and knee pain, respectively, were pooled using random-effects meta-analysis. Overall quality of the literature was assessed through Grading of Recommendations, Assessment, Development, and Evaluation.

RESULTS

Twenty-five trials (2,000 participants) were included in the review assessing the effect of invasive procedures over sham. Conditions included low back (N = 7 trials), arthritis (4), angina (4), abdominal pain (3), endometriosis (3), biliary colic (2), and migraine (2). Thirteen trials (52%) reported an adequate concealment of allocation. Fourteen studies (56%) reported on adverse events. Of these, the risk of any adverse event was significantly higher for invasive procedures (12%) than sham procedures (4%; risk difference = 0.05, 95% confidence interval [CI] = 0.01 to 0.09, P = 0.01, I2 = 65%). In the two meta-analysis subsets, the standardized mean difference for reduction of low back pain in seven studies (N = 445) was 0.18 (95% CI = -0.14 to 0.51, P = 0.26, I2 = 62%), and for knee pain in three studies (N = 496) it was 0.04 (95% CI = -0.11 to 0.19, P = 0.63, I2 = 36%). The relative contribution of within-group improvement in sham treatments accounted for 87% of the effect compared with active treatment across all conditions.

CONCLUSIONS

There is little evidence for the specific efficacy beyond sham for invasive procedures in chronic pain. A moderate amount of evidence does not support the use of invasive procedures as compared with sham procedures for patients with chronic back or knee pain. Given their high cost and safety concerns, more rigorous studies are required before invasive procedures are routinely used for patients with chronic pain.

Radiofrequency neurotomy in chronic lumbar and sacroiliac joint pain: A meta-analysis

BACKGROUND

Effective treatment of low back pain (LBP) originating in the lumbar and sacroiliac joints is difficult to achieve. The objective of the current study was to compare the clinical effectiveness of radiofrequency (RF) neurotomy versus conservative nonsurgical approaches for the management of chronic lumbar and sacroiliac joint pain.

METHODS

The PICOS framework was adhered to (P [population]: patients with a history of chronic function-limiting lumbar and sacroiliac joint pain lasting at least 6 months; I [intervention]: RF neurotomy; C [comparator]: other nonsurgical treatments; O [outcomes]: the Oswestry Disability Index (ODI), measurement for pain, and a quality of life (QoL) questionnaire; S [study design]: meta-analysis). Two trained investigators systematically searched Medline, Cochrane, EMBASE, and ISI Web of Knowledge databases for relevant studies published in English through March 2019.

RESULTS

Patients treated with RF neurotomy (n = 528) had significantly greater improvement in ODI scores, pain scores and QoL measured by EQ-5D compared with controls (n = 457); however, significant heterogeneity was observed when data were pooled from eligible studies. In subgroup analyses, patients who received RF neurotomy had a significantly greater improvement in ODI scores compared with those with sham treatment. Patients treated with RF achieved significantly greater improvement in pain scores compared with controls who received sham treatment or medical treatment. In a subgroup analysis of pain in the sacroiliac joint and in lumbar facet joints, the RF neurotomy group achieved a significantly greater improvement in ODI score and pain scores compared with the control group. The ODI score and pain score were improved after 2 months of follow up in the analyses stratified by follow-up duration.

CONCLUSIONS

Use of RF neurotomy as an intervention for chronic lumbar and sacroiliac joint pain led to improved function; however, larger, more directly comparable studies are needed to confirm this study's findings.

Predictors of Response to a Medial Branch Block: MRI Analysis of the Lumbar Spine

The aim of this study was to determine the association between radiologic spinal pathology and the response to medial branches block (MBB). This retrospective observational study compared 165 patients. A successful response was defined as ≥30% or a 2-point reduction in the numeric rating scale (NRS) compared with the baseline at the 1-month follow-up. The facet angle, facet angle difference, facet joint degeneration, disc height and spondylolisthesis grade were analyzed from an MRI at the L3 to S1 levels. Univariate and multivariate logistic regression analyses were used to evaluate independent factors associated with a successful response of MBB. In the univariate analysis, the disc height at L5-S1 and facet angle difference at L3-4 were lower in the positive responders (p = 0.022 and p = 0.087, respectively). In the multivariate analysis, the facet angle difference at L3-4 and disc height at L5-S1 were independent factors associated with a successful response (odds ratio = 0.948; p = 0.038 and odds ratio = 0.864; p = 0.038, respectively). In patients with a degenerative disc at L5-S1, MBB can lead to a good response for at least one month. In patients with facet tropism at L3-4 level, the response to MBB after one month is likely to be poor.

Best practice in radiofrequency denervation of the lumbar facet joints: a consensus technique

Background

Radiofrequency denervation is used to treat selected people with low back pain. Recent trials have been criticised for using a sub-optimal intervention technique.

Objectives

To achieve consensus on a best practice technique for administering radiofrequency denervation of the lumbar facet joints to selected people with low back pain.

Study design

A consensus of expert professionals in the area of radiofrequency denervation of the lumbar facet joints.

Methods

We invited a clinical member from the 30 most active UK departments in radiofrequency pain procedures and two overseas clinicians with specific expertise to a 1 day consensus meeting. Drawing on the known anatomy of the medial branch, the theoretical basis of radiofrequency procedures, a survey of current practice and collective expertise, delegates were facilitated to reach consensus on the best practice technique.

Results

The day was attended by 24 UK and international clinical experts. Attendees agreed a best practice technique for the conduct of radiofrequency denervation of the lumbar facet joints.

Limitations

This consensus was based on a 1 day meeting of 24 clinical experts who attended and took part in the discussions. The agreed technique has not been subject to input from a wider community of experts.

Conclusions

Current best practice for radiofrequency denervation has been agreed for use in a UK trial. Group members intend immediate implementation in their respective trusts. We propose using this in a planned Randomised Controlled Trial (RCT) of radiofrequency denervation for selected people with low back pain.

Low back pain

Low back pain affects individuals of all ages and is a leading contributor to disease burden worldwide. Despite advancements in assessment and treatment methods, the management of low back pain remains a challenge for researchers and clinicians alike. One reason for the limited success in identifying effective treatments is the large variation in the manifestations, possible causes, precipitating and maintaining factors, course, prognosis and consequences in terms of activity interference and quality of life. However, despite these challenges, steady progress has been achieved in the understanding of back pain, and important steps in the understanding of the psychological and social risk factors, genetics and brain mechanisms of low back pain have been made. These new findings have given impetus to the development of new diagnostic procedures, evidence-based screening methods and more targeted interventions, which underscore the need for a multidisciplinary approach to the management of low back pain that integrates biological, psychological and social aspects.

Audit of Conservative Management of Chronic Low Back Pain in a Secondary Care Setting – Part I: Facet Joint and Sacroiliac Joint Interventions

The work of a chronic back pain service in secondary care in the West Midlands is reported. The service offers acupuncture, spinal injection procedures, osteopathy and a range of other interventions for patients whose back pain has not responded to conservative management. This section of the report focuses on injection procedures for lumbar facet joint and sacroiliac joint pain, which have been shown to be the cause of chronic low back pain in 16–40% and 13–19% of patients respectively. Diagnosis relies on the use of intra-articular or sensory nerve block injections with local anaesthetic. Possible treatments following diagnosis include intra-articular corticosteroid, radiofrequency denervation (for facet joint pain) or ligament prolotherapy injections (for sacroiliac joint pain). The results of several hospital audits are reported. At six month follow up, 50% of 38 patients undergoing radiofrequency denervation following diagnostic blocks for facet joint pain had improved by more than 50%, compared to 29% of 34 patients treated with intra-articular corticosteroid injection. Sixty three per cent of 19 patients undergoing prolotherapy following diagnostic block injection for sacroiliac joint pain had improved at six months, compared to 33% of 33 who had intra-articular corticosteroid. Both radiofrequency denervation and sacroiliac prolotherapy showed good long-term outcomes at one year.

Unique aspects of clinical trials of invasive therapies for chronic pain

Nearly all who review the literature conclude that the role of invasive procedures to treat chronic pain is poorly characterized because of the lack of “definitive” studies. The overt nature of invasive treatments, along with the risks, technical skills, and costs involved create challenges to study them. However, these challenges do not completely preclude evaluating invasive procedure effectiveness and safety using well-designed methods. This article reviews the challenges of studying outcomes of invasive therapies to treat pain and discuss possible solutions. Although the following discussion can apply to most invasive therapies to treat chronic pain, it is beyond the scope of the article to individually cover every invasive therapy used. Therefore, most of the examples focus on injection therapies to treat spine pain, spinal cord stimulation, and intrathecal drug therapies.

Effectiveness of Lumbar Facet Joint Blocks and Predictive Value before Radiofrequency Denervation: The Facet Treatment Study (FACTS), a Randomized, Controlled Clinical Trial

WHAT WE ALREADY KNOW ABOUT THIS TOPIC

WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: With facet interventions under scrutiny, the authors' objectives were to determine the effectiveness of different lumbar facet blocks and their ability to predict radiofrequency ablation outcomes.

METHODS

A total of 229 participants were randomized in a 2:2:1 ratio to receive intraarticular facet injections with bupivacaine and steroid, medial branch blocks, or saline. Those with a positive 1-month outcome (a 2-point or more reduction in average pain score) and score higher than 3 (positive satisfaction) on a 5-point satisfaction scale were followed up to 6 months. Participants in the intraarticular and medial branch block groups with a positive diagnostic block (50% or more relief) who experienced a negative outcome proceeded to the second phase and underwent radiofrequency ablation, while all saline group individuals underwent ablation. Coprimary outcome measures were average reduction in numerical rating scale pain score 1 month after the facet or saline blocks, and average numerical rating scale pain score 3 months after ablation.

RESULTS

Mean reduction in average numerical rating scale pain score at 1 month was 0.7 ± 1.6 in the intraarticular group, 0.7 ± 1.8 in the medial branch block group, and 0.7 ± 1.5 in the placebo group; P = 0.993. The proportions of positive blocks were higher in the intraarticular (54%) and medial branch (55%) groups than in the placebo group (30%; P = 0.01). Radiofrequency ablation was performed on 135 patients (45, 48, and 42 patients from the intraarticular, medial branch, and saline groups, respectively). The average numerical rating scale pain score at 3 months was 3.0 ± 2.0 in the intraarticular, 3.2 ± 2.5 in the medial branch, and 3.5 ± 1.9 in the control group (P = 0.493). At 3 months, the proportions of positive responders in the intraarticular, medial branch block, and placebo groups were 51%, 56%, and 24% for the intraarticular, medial branch, and placebo groups, respectively (P = 0.005).

CONCLUSIONS

This study establishes that facet blocks are not therapeutic. The higher responder rates in the treatment groups suggest a hypothesis that facet blocks might provide prognostic value before radiofrequency ablation.

Facet joint syndrome: from diagnosis to interventional management

Abstract

Low back pain (LBP) is the most common pain syndrome, and is an enormous burden and cost generator for society. Lumbar facet joints (FJ) constitute a common source of pain, accounting for 15–45% of LBP. Facet joint degenerative osteoarthritis is the most frequent form of facet joint pain. History and physical examination may suggest but not confirm facet joint syndrome. Although imaging (radiographs, MRI, CT, SPECT) for back pain syndrome is very commonly performed, there are no effective correlations between clinical symptoms and degenerative spinal changes. Diagnostic positive facet joint block can indicate facet joints as the source of chronic spinal pain. These patients may benefit from specific interventions to eliminate facet joint pain such as neurolysis, by radiofrequency or cryoablation. The purpose of this review is to describe the anatomy, epidemiology, clinical presentation, and radiologic findings of facet joint syndrome. Specific interventional facet joint management will also be described in detail.

Teaching points

• Lumbar facet joints constitute a common source of pain accounting of 15–45%.

• Facet arthrosis is the most frequent form of facet pathology.

• There are no effective correlations between clinical symptoms, physical examination and degenerative spinal changes.

• Diagnostic positive facet joint block can indicate facet joints as the source of pain.

• After selection processing, patients may benefit from facet joint neurolysis, notably by radiofrequency or cryoablation.

Cryoneurolysis for the treatment of cervical facet joint syndrome: a technical note

Objective

Neck pain has an annual prevalence of 30%. A frequent cause of neck pain is cervical facet joint pain. In cases of refractory cervical facet joint pain, radiofrequency can be employed, but the grade of evidence attested in systematic reviews is fair. Cryoneurolysis has been reported to induce favorable outcomes in lumbar facet joint pain. We sought to examine the feasibility of cervical facet joint cryoneurolysis.

Setting

Tertiary academic pain center.

Patients and methods

We report here the operative technique of cervical facet joint cryoneurolysis for patients with cervical facet joint pain. The procedure is performed under CT-guidance. The lesion points are defined with the help of sensory stimulation.

Results

Six cervical facet joint denervations were carried out in five patients. All patients had an uneventful course with adequate pain relief. Apart from soreness of the paravertebral muscles no severe side effects were encountered.

Conclusion

This is the first report of cryoneurolysis for the treatment of cervical facet joint pain. The technique is feasible and warrants further studies.

The efficacy of conventional radiofrequency denervation in patients with chronic low back pain originating from the facet joints: a meta-analysis of randomized controlled trials

BACKGROUND CONTEXT

Radiofrequency denervation is commonly used for the treatment of chronic facet joint pain that has been refractory to more conservative treatments, although the evidence supporting this treatment has been controversial.

PURPOSE

We aimed to elucidate the precise effects of radiofrequency denervation in patients with low back pain originating from the facet joints relative to those obtained using control treatments, with particular attention to consistency in the denervation protocol.

STUDY DESIGN/SETTING

A meta-analysis of randomized controlled trials was carried out.

PATIENT SAMPLE

Adult patients undergoing radiofrequency denervation or control treatments (sham or epidural block) for facet joint disease of the lumbar spine comprised the patient sample.

OUTCOME MEASURES

Visual analog scale (VAS) pain scores were measured and stratified by response of diagnostic block procedures.

METHOD

We searched PubMed, Embase, Web of Science, and the Cochrane Database for randomized controlled trials regarding radiofrequency denervation and control treatments for back pain. Changes in VAS pain scores of the radiofrequency group were compared with those of the control group as well as the minimal clinically important difference (MCID) for back pain VAS. Meta-regression model was developed to evaluate the effect of radiofrequency treatment according to responses of diagnostic block while controlling for other variables. We then calculated mean differences and 95% confidence intervals (CIs) using random-effects models.

RESULTS

We included data from seven trials involving 454 patients who had undergone radiofrequency denervation (231 patients) and control treatments such as sham or epidural block procedures (223 patients). The radiofrequency group exhibited significantly greater improvements in back pain score when compared with the control group for 1-year follow-up. Although the average improvement in VAS scores exceeded the MCID, the lower limit of the 95% CI encompassed the MCID. A subgroup of patients who responded very well to diagnostic block procedures demonstrated significant improvements in back pain relative to the control group at all times. When placed into our meta-regression model, the response to diagnostic block procedure was responsible for a statistically significant portion of treatment effect. Studies published over the last two decades revealed that radiofrequency denervation reduced back pain significantly in patients with facet joint disease compared with the MCID and control treatments.

CONCLUSIONS

Conventional radiofrequency denervation resulted in significant reductions in low back pain originating from the facet joints in patients showing the best response to diagnostic block over the first 12 months when compared with sham procedures or epidural nerve blocks.

Opioid Reduction Following Interventional Procedures for Chronic Pain: A Synthesis of the Evidence

The past decade has witnessed the tremendous growth of procedures to treat chronic pain, which has resulted in increased third-party scrutiny. Although most of these procedures appear to be associated with significant pain relief, at least in the short and intermediate term, their ability to improve secondary outcome measures, including function and work status is less clear-cut. One of these secondary outcome measures that has garnered substantial interest in the pain and general medical communities is whether interventions can reduce opioid intake, which is associated with significant risks that in most cases outweigh the benefits in the long term. In the article, we examine whether procedural interventions for chronic pain can reduce opioid intake. Most studies that have examined analgesic reduction as a secondary outcome measure have not separated opioid and nonopioid analgesics, and, among those studies that have, few have demonstrated between-group differences. Reasons for failure to demonstrate opioid reduction can be broadly classified into procedural, design-related, clinical, psychosocial, biological, and pharmacological categories, all of which are discussed. In the future, clinical trials in which this outcome is examined should be designed to evaluate this, at least on a preliminary basis.

Thermocoagulation of the Medial Branch of the Dorsal Branch of the Lumbal Spinal Nerve: Flouroscopy Versus CT

Objective

For radiofrequency neurotomy of the medial branch of the lumbar dorsal rami, physicians use techniques guided either by fluoroscopy or computerized tomography (CT), and advocate for their respective techniques. Crucial to the choice of technique is how well each can capture the target nerve. The present study was, therefore, undertaken to assess in cadavers the accuracy of fluoroscopic-guided and CT-guided techniques.

Design

In10 cadavers preserved with Thiel's method, electrodes with 10mm active tips were placed in supine position on the right using a fluoroscopic-guided technique, and on the left using a CT-guided technique. Using a special dissection approach, the relationship between the target nerve and the tip of the electrode was revealed. The displacement between electrode and the nerve, and the extent to which the electrode was parallel to the nerve, were measured with callipers.

Results

Under fluoroscopy guidance, electrodes were placed accurately beside the nerve, and were parallel to it for 9 ±1.9 mm. In only two cases did the electrode pass too deeply. Under CT guidance, electrodes often failed to reach the nerve, but when they did they were parallel to it for only 3.2 ± 3.2 mm. In seven cases, the electrode passed too deeply beyond the target nerve.

Conclusion

The fluoroscopy-guided technique can be relied upon to achieve optimal placement of electrodes on the lumbar medial branches. The CT-guided technique fails to do so, and should not be used in practice until a modified version has been developed and validated.

Relationship between paravertebral muscle twitching and long-term effects of radiofrequency medial branch neurotomy

Background

To achieve a prolonged therapeutic effect in patients with lumbar facet joint syndrome, radiofrequency medial branch neurotomy (RF-MB) is commonly performed. The purpose of this study was to evaluate the prognostic value of paravertebral muscle twitching when performing RF-MB in patients with lumbar facet joint syndrome.

Methods

We collected and analyzed data from 68 patients with confirmed facet joint syndrome. Sensory stimulation was performed at 50 Hz with a 0.5 V cut-off value. Patients were divided into 3 groups according to the twitching of the paravertebral muscle during 2 Hz motor stimulation: ‘Complete’, when twitching was observed at all needles; ‘Partial’, when twitching was present at 1 or 2 needles; and ‘None’, when no twitching was observed. The relationship between the long-term effects of RF-MB and paravertebral muscle twitching was analyzed.

Results

The mean effect duration of RF-MB was 4.6, 5.8, and 7.0 months in the None, Partial, and Complete groups, respectively (P = 0.47). Although the mean effect duration of RF-MB did not increase significantly in proportion to the paravertebral muscle twitching, the Complete group had prolonged effect duration (> 6 months) than the None group in subgroup analysis. (P = 0.03).

Conclusions

Paravertebral muscle twitching while performing lumbar RF-MB may be a reliable predictor of long-term efficacy when sensory provocation under 0.5 V is achieved. However, further investigation may be necessary for clarifying its clinical significance.

Does early change predict long-term (6 months) improvements in subjects who receive manual therapy for low back pain?

Early change is commonly assessed for manual therapy interventions and has been used to determine treatment appropriateness. However, current studies have only explored the relationship of between or within-session changes and short-/medium-term outcomes. The goal of this study was to determine whether pain changes after two weeks of pragmatic manual therapy could predict those participants with chronic low back pain who demonstrate continued improvements at 6-month follow-up. This study was a retrospective observational design. Univariate logistic regression analyses were performed using a 33% and a 50% pain change to predict improvement. Those who experienced a ≥33% pain reduction by 2 weeks had 6.98 (95% CI = 1.29, 37.53) times higher odds of 50% improvement on the GRoC and 4.74 (95% CI = 1.31, 17.17) times higher odds of 50% improvement on the ODI (at 6 months). Subjects who reported a ≥50% pain reduction at 2 weeks had 5.98 (95% CI = 1.56, 22.88) times higher odds of a 50% improvement in the GRoC and 3.99 (95% CI = 1.23, 12.88) times higher odds of a 50% improvement in the ODI (at 6 months). Future studies may investigate whether a change in plan of care is beneficial for patients who are not showing early improvement predictive of a good long-term outcome.

Esoteric Connective Tissue Therapy for chronic low back pain to reduce pain, and improve functionality and general well-being compared with physiotherapy: study protocol for a randomised controlled trial

BACKGROUND

Low back pain causes more global disability than any other condition. Once the acute pain becomes chronic, about two-thirds of sufferers will not fully recover after 1-2 years. There is a paucity of effective treatments for non-specific, chronic low back pain. It has been noted that low back pain is associated with changes in the connective tissue in the affected area, and a very low-impact treatment, Esoteric Connective Tissue Therapy (ECTT), has been developed to restore flexibility in connective tissue. ECTT uses patterns of very small, circular movements, to the legs, arms, spine, sacrum and head, which anecdotally are effective in pain relief. In an unpublished single-arm phase I/II trial with chronic pain patients, ECTT showed a 56% reduction in pain after five treatments and 45% and 54% improvements at 6 months and 7-9 years of follow-up respectively.

METHODS

The aim of this randomised controlled trial is to compare ECTT with physiotherapy for reducing pain and improving physical function and physical and mental well-being in patients with chronic low back pain. The trial will be held at two hospitals in Vietnam. One hundred participants with chronic low back pain greater than or equal to 40/100 on the visual analogue scale will be recruited and randomised to either ECTT or physiotherapy. Four weekly treatments will be provided by two experienced ECTT practitioners (Treatment Group, 40 minutes each) and hospital-employed physiotherapy nurses (Control Group, 50 minutes). The primary outcomes will be changes in pain, physical function per the Quebec Pain Functionality Questionnaire and physical and mental well-being recorded by the Short Form Health Survey (SF-36), with mixed modelling used as the primary statistical tool because the data are longitudinal. Initial follow-up will be at either 4 or 8 months, with a second follow-up after 12 months.

DISCUSSION

The trial design has important strengths, because it is to be conducted in hospitals under medical supervision, because ECTT is to be compared with a standard therapy and because the assessor and analyst are to be blinded. The findings from this trial will provide evidence of the efficacy of ECTT for chronic low back pain compared with standard physiotherapy treatment.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, ACTRN12616001196437 . Registered on 30 August 2016.

Utilization of Facet Joint and Sacroiliac Joint Interventions in Medicare Population from 2000 to 2014: Explosive Growth Continues!

Increasing utilization of interventional techniques in managing chronic spinal pain, specifically facet joint interventions and sacroiliac joint injections, is a major concern of healthcare policy makers. We analyzed the patterns of utilization of facet and sacroiliac joint interventions in managing chronic spinal pain. The results showed significant increase of facet joint interventions and sacroiliac joint injections from 2000 to 2014 in Medicare FFS service beneficiaries. Overall, the Medicare population increased 35 %, whereas facet joint and sacroiliac joint interventions increased 313.3 % per 100,000 Medicare population with an annual increase of 10.7 %. While the increases were uniform from 2000 to 2014, there were some decreases noted for facet joint interventions in 2007, 2010, and 2013, whereas for sacroiliac joint injections, the decreases were noted in 2007 and 2013. The increases were for cervical and thoracic facet neurolysis at 911.5 % compared to lumbosacral facet neurolysis of 567.8 %, 362.9 % of cervical and thoracic facet joint blocks, 316.9 % of sacroiliac joints injections, and finally 227.3 % of lumbosacral facet joint blocks.

Randomised sham-controlled double-blind multicentre clinical trial to ascertain the effect of percutaneous radiofrequency treatment for lumbar facet joint pain

AIMS

The aim of this study was to compare the effect of a percutaneous radiofrequency heat lesion at the medial branch of the primary dorsal ramus with a sham procedure, for the treatment of lumbar facet joint pain.

PATIENTS AND METHODS

A randomised sham-controlled double blind multicentre trial was carried out at the multidisciplinary pain centres of two hospitals. A total of 60 patients aged > 18 years with a history and physical examination suggestive of facet joint pain and a decrease of ≥ 2 on a numerical rating scale (NRS 0 to 10) after a diagnostic facet joint test block were included. In the treatment group, a percutaneous radiofrequency heat lesion (80^oC during 60 seconds per level) was applied to the medial branch of the primary dorsal ramus. In the sham group, the same procedure was undertaken without for the radiofrequency lesion. Both groups also received a graded activity physiotherapy programme. The primary outcome measure was decrease in pain. A secondary outcome measure was the Global Perceived Effect scale (GPE).

RESULTS

There was a statistically significant effect on the level of pain in the factor Period (T0-T1). However, there was no statistically significant difference with the passage of time between the groups (Group × Period) or in the factor Group. In the crossover group, 11 of 19 patients had a decrease in NRS of ≥ 2 at one month crossover (p = 0.65). There was no statistically significant difference in satisfaction with the passage of time between the groups (Group × Period). The independent factors Group and Period also showed no statistically significant difference. There was no statistically significant Group × Period effect for recovery, neither an effect of Group or of Period.

CONCLUSION

The null hypothesis of no difference in the decrease in pain and in GPE between the treatment and sham groups cannot be rejected. Post hoc analysis revealed that the age of the patients and the severity of the initial pain significantly predicted a positive outcome. Cite this article: Bone Joint J 2016;98-B:1526-33.

Percutaneous radiofrequency facet capsule denervation as an alternative target in lumbar facet syndrome

OBJECTIVES

Percutaneous radiofrequency denervation of the medial dorsal branch is often used in chronic low back pain of intervertebral facet etiology, which is sometimes difficult to perform and recurrence of pain often ensues. We theorized that shifting the target of RF coagulation to the facet joint capsule would provide an easier target and a longer-lived pain relieving response.

PATIENTS AND METHODS

A prospective randomized controlled trial where 120 patients diagnosed with CLBP of a confirmed facet origin were randomly divided into three equal groups, the first was submitted to percutaneous radiofrequency coagulation of the facet joint capsule, the second underwent percuataneous denervation of the medial dorsal branch and the third did not receive radiofrequency lesioning. All the three groups received local injection of a mixture of local anesthetic and steroid. Cases were followed for up to 3 years.

RESULTS

87(72.5%) patients were females. By 3 months' post procedure, improvement in VAS was significantly better than pretreatment levels in all groups (p<0.05). The control group lost improvement by 1-year follow-up (p=0.017). At 2 years' follow-up, the joint capsule denervation group maintained significant improvement (p=0.033) whereas the medial branch denervation group lost its significant effect (p=0.479). By the end of follow-up period, only joint capsule denervation group kept significant improvement (p=0.026).

CONCLUSION

In CLBP of facet origin, shifting the target of percutaneous radiofrequency to the facet joint capsule provides an easier technique with an extended period of pain relief compared to the medial dorsal branch of the facet joint.

Ultrasound-Guided Radiofrequency Treatment of Intercostal Nerves for the Prevention of Incidental Pain Arising Due to Rib Metastasis

BACKGROUND

Breakthrough pain (BTP) arising due to rib metastasis is very distressing and often very difficult to manage by titration of traditional analgesics. This study is undertaken to determine the efficacy of radiofrequency (RF) treatment of intercostal nerves for the prevention of BTP.

METHODS

The RF treatment of the intercostal nerves was carried out in 25 patients with uncontrolled BTP arising out of the rib metastasis. The intensity and episode of BTP, background pain, opioid dose, functional status (Karnofky score), and quality of life (Short-Form Health Survey [SF-36]) were noted at baseline visit and subsequently after the RF treatment.

RESULTS

After the RF treatment, there was more than 50% decrease in both intensity and frequency of BTP in more than 50% of patients for 3 months, and there was more than 50% decrease in BTP opioid dose in more than 50% of patients throughout the study period. There was also significant improvement in background pain, functional status, and the quality of life after the RF. Interestingly, pain relief, lowering of opioid dose, and functional status improvement were found mostly in patients with mixed and neuropathic type of pain and in patients in whom the metastasis were confined to the ribs only.

CONCLUSION

RF of the intercostal nerves is effective in preventing and deceasing the severity of BTP arising due to rib metastasis in selected group of patients with mixed and neuropathic type of pain and with the metastasis involving the ribs only.

Medial Branch Blocks or Intra-Articular Injections as a Prognostic Tool Before Lumbar Facet Radiofrequency Denervation: A Multicenter, Case-Control Study

BACKGROUND

Medial branch blocks (MBBs) and intra-articular (IA) facet joint injections are both used to diagnose facet joint pain and are presumed to be equivalent. No study has sought to determine which has a better prognostic value before radiofrequency (RF) denervation.

METHODS

A case-control study was performed at 4 institutions in which RF denervation outcomes in patients who obtained 50% or more pain relief from either MBB (n = 212) or IA injections (n = 212) were compared. "Control" patients (MBB) were matched to "cases" by treating physician, last name, and date of treatments. During data mining, 87 patients were identified who underwent RF ablation after receiving both IA injections and MBB and were used for secondary analyses.

RESULTS

A total of 70.3% of MBB patients experienced 50% or more pain relief at the 3-month follow-up versus 60.8% in those who underwent IA injections (P = 0.041). In multivariable analysis, undergoing MBB was associated with RF treatment success (odds ratio [OR], 1.57; 95% confidence interval [95% CI], 1.0-2.39; P = 0.036), whereas opioid use (OR, 0.52; 95% CI, 0.34-0.79; P = 0.002) and previous back surgery (OR, 0.60; 95% CI, 0.38-0.95; P = 0.028) were associated with treatment failure. No significant differences were noted between MBB alone and combination treatment or single versus multiple blocks. In the secondary multivariable analysis including the combination IA + MBB group, MBB alone was again independently associated with an RF ablation treatment success (OR, 1.73; 95% CI, 1.12-2.67; P = 0.014).

CONCLUSIONS

When used as a prognostic tool before lumbar facet radiofrequency, MBB may be associated with a higher success rate than IA injections. Our results should be confirmed by large, prospective, randomized studies.

Bayesian multiple imputation for missing multivariate longitudinal data from a Parkinson's disease clinical trial

In Parkinson's disease (PD) clinical trials, Parkinson's disease is studied using multiple outcomes of various types (e.g. binary, ordinal, continuous) collected repeatedly over time. The overall treatment effects across all outcomes can be evaluated based on a global test statistic. However, missing data occur in outcomes for many reasons, e.g. dropout, death, etc., and need to be imputed in order to conduct an intent-to-treat analysis. We propose a Bayesian method based on item response theory to perform multiple imputation while accounting for multiple sources of correlation. Sensitivity analysis is performed under various scenarios. Our simulation results indicate that the proposed method outperforms standard methods such as last observation carried forward and separate random effects model for each outcome. Our method is motivated by and applied to a Parkinson's disease clinical trial. The proposed method can be broadly applied to longitudinal studies with multiple outcomes subject to missingness.

To what extent are surgery and invasive procedures effective beyond a placebo response? A systematic review with meta-analysis of randomised, sham controlled trials

OBJECTIVES

To assess the quantity and quality of randomised, sham-controlled studies of surgery and invasive procedures and estimate the treatment-specific and non-specific effects of those procedures.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

We searched PubMed, EMBASE, CINAHL, CENTRAL (Cochrane Library), PILOTS, PsycInfo, DoD Biomedical Research, clinicaltrials.gov, NLM catalog and NIH Grantee Publications Database from their inception through January 2015.

STUDY SELECTION

We included randomised controlled trials of surgery and invasive procedures that penetrated the skin or an orifice and had a parallel sham procedure for comparison.

DATA EXTRACTION AND ANALYSIS

Three authors independently extracted data and assessed risk of bias. Studies reporting continuous outcomes were pooled and the standardised mean difference (SMD) with 95% CIs was calculated using a random effects model for difference between true and sham groups.

RESULTS

55 studies (3574 patients) were identified meeting inclusion criteria; 39 provided sufficient data for inclusion in the main analysis (2902 patients). The overall SMD of the continuous primary outcome between treatment/sham-control groups was 0.34 (95% CI 0.20 to 0.49; p<0.00001; I(2)=67%). The SMD for surgery versus sham surgery was non-significant for pain-related conditions (n=15, SMD=0.13, p=0.08), marginally significant for studies on weight loss (n=10, SMD=0.52, p=0.05) and significant for gastroesophageal reflux disorder (GERD) studies (n=5, SMD=0.65, p<0.001) and for other conditions (n=8, SMD=0.44, p=0.004). Mean improvement in sham groups relative to active treatment was larger in pain-related conditions (78%) and obesity (71%) than in GERD (57%) and other conditions (57%), and was smaller in classical-surgery trials (21%) than in endoscopic trials (73%) and those using percutaneous procedures (64%).

CONCLUSIONS

The non-specific effects of surgery and other invasive procedures are generally large. Particularly in the field of pain-related conditions, more evidence from randomised placebo-controlled trials is needed to avoid continuation of ineffective treatments.

Lumbar Zygapophyseal (Facet) Joint Pain

Lumbar zygapophyseal joints act as primary pain generators in at least 10-15% of patients with chronic low back pain.Diagnostic nerve blocks are the most reliable way to diagnose lumbar zygapophyseal joint pain.IASP recommends either controlled or comparative blocks for diagnosis of zygapophyseal joint pain as there is a significant incidence of false positives with single blocks.Management should be multimodal comprising education, exercises, analgesics and procedural interventions to achieve functional restoration.There is a need for further RCTs with standardised diagnostic criteria and outcome measures as well as long-term data to determine the efficacy of radiofrequency denervation.

Radiofrequency denervation for chronic low back pain

BACKGROUND

Radiofrequency (RF) denervation, an invasive treatment for chronic low back pain (CLBP), is used most often for pain suspected to arise from facet joints, sacroiliac (SI) joints or discs. Many (uncontrolled) studies have shown substantial variation in its use between countries and continued uncertainty regarding its effectiveness.

OBJECTIVES

The objective of this review is to assess the effectiveness of RF denervation procedures for the treatment of patients with CLBP. The current review is an update of the review conducted in 2003.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, three other databases, two clinical trials registries and the reference lists of included studies from inception to May 2014 for randomised controlled trials (RCTs) fulfilling the inclusion criteria. We updated this search in June 2015, but we have not yet incorporated these results.

SELECTION CRITERIA

We included RCTs of RF denervation for patients with CLBP who had a positive response to a diagnostic block or discography. We applied no language or date restrictions.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently selected RCTs, extracted data and assessed risk of bias (RoB) and clinical relevance using standardised forms. We performed meta-analyses with clinically homogeneous studies and assessed the quality of evidence for each outcome using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

In total, we included 23 RCTs (N = 1309), 13 of which (56%) had low RoB. We included both men and women with a mean age of 50.6 years. We assessed the overall quality of the evidence as very low to moderate. Twelve studies examined suspected facet joint pain, five studies disc pain, two studies SI joint pain, two studies radicular CLBP, one study suspected radiating low back pain and one study CLBP with or without suspected radiation. Overall, moderate evidence suggests that facet joint RF denervation has a greater effect on pain compared with placebo over the short term (mean difference (MD) -1.47, 95% confidence interval (CI) -2.28 to -0.67). Low-quality evidence indicates that facet joint RF denervation is more effective than placebo for function over the short term (MD -5.53, 95% CI -8.66 to -2.40) and over the long term (MD -3.70, 95% CI -6.94 to -0.47). Evidence of very low to low quality shows that facet joint RF denervation is more effective for pain than steroid injections over the short (MD -2.23, 95% CI -2.38 to -2.08), intermediate (MD -2.13, 95% CI -3.45 to -0.81), and long term (MD -2.65, 95% CI -3.43 to -1.88). RF denervation used for disc pain produces conflicting results, with no effects for RF denervation compared with placebo over the short and intermediate term, and small effects for RF denervation over the long term for pain relief (MD -1.63, 95% CI -2.58 to -0.68) and improved function (MD -6.75, 95% CI -13.42 to -0.09). Lack of evidence of short-term effectiveness undermines the clinical plausibility of intermediate-term or long-term effectiveness. When RF denervation is used for SI joint pain, low-quality evidence reveals no differences from placebo in effects on pain (MD -2.12, 95% CI -5.45 to 1.21) and function (MD -14.06, 95% CI -30.42 to 2.30) over the short term, and one study shows a small effect on both pain and function over the intermediate term. RF denervation is an invasive procedure that can cause a variety of complications. The quality and size of original studies were inadequate to permit assessment of how often complications occur.

AUTHORS' CONCLUSIONS

The review authors found no high-quality evidence suggesting that RF denervation provides pain relief for patients with CLBP. Similarly, we identified no convincing evidence to show that this treatment improves function. Overall, the current evidence for RF denervation for CLBP is very low to moderate in quality; high-quality evidence is lacking. High-quality RCTs with larger patient samples are needed, as are data on long-term effects.

Efficacy of needle-placement technique in radiofrequency ablation for treatment of lumbar facet arthropathy

Background

Many studies have assessed the efficacy of radiofrequency ablation to denervate the facet joint as an interventional means of treating axial low-back pain. In these studies, varying procedural techniques were utilized to ablate the nerves that innervate the facet joints. To date, no comparison studies have been performed to suggest superiority of one technique or even compare the prevalence of side effects and complications.

Materials and methods

A retrospective chart review was performed on patients who underwent a lumbar facet denervation procedure. Each patient’s chart was analyzed for treatment technique (early versus advanced Australian), preprocedural visual numeric scale (VNS) score, postprocedural VNS score, duration of pain relief, and complications.

Results

Pre- and postprocedural VNS scores and change in VNS score between the two groups showed no significant differences. Patient-reported benefit and duration of relief was greater in the advanced Australian technique group (P=0.012 and 0.022, respectively). The advanced Australian technique group demonstrated a significantly greater median duration of relief (4 months versus 1.5 months, P=0.022). Male sex and no pain-medication use at baseline were associated with decreased postablation VNS scores, while increasing age and higher preablation VNS scores were associated with increased postablation VNS scores. Despite increasing age being associated with increased postablation VNS scores, age and the advanced Australian technique were found to confer greater patient self-reported treatment benefit.

Conclusion

The advanced Australian technique provides a significant benefit over the early Australian technique for the treatment of lumbar facet pain, both in magnitude and duration of pain relief.

Optimal Temperature for Radiofrequency Ablation of Lumbar Medial Branches for Treatment of Facet-Mediated Back Pain

BACKGROUND

Radiofrequency ablation (RFA) of the medial branch nerves that innervate the facet joints is a well-established treatment modality; however, studies to determine the optimal radiofrequency ablation temperature are lacking. A wide range (70 to 90°C) has been used. This study aimed to compare outcomes with two set temperatures for the lumbar facet medial branch ablation, 90 and 80°C.

METHODS

This retrospective study compared the degree of patient self-reported functional improvement relief, postoperative opioid dose changes, as well as duration among lumbar facet medial branch (RFA) patients who had the procedures performed at 80 or 90°C.

RESULTS

Patients who underwent the procedure at 90°C had 3.1 (95% CI 1.7, 6.5) times the odds (P = 0.0004) of reporting functional improvement of at least 50% when compared to those who underwent neurotomy at 80°C. For self-reported functional improvement greater or equal to 75%, the results were sustained with an odds ratio of 2.8 (95% CI 1.2, 5.7) favoring those with 90°C temperature neurotomy (P = 0.002).

CONCLUSION

There seems to be significant functional improvement associated with temp of 90°C compared to 80°C, with no added risk of complications. Randomized controlled studies are warranted.

Interventional Therapies for Chronic Low Back Pain: A Focused Review (Efficacy and Outcomes)

Context:

Lower back pain is considered to be one of the most common complaints that brings a patient to a pain specialist. Several modalities in interventional pain management are known to be helpful to a patient with chronic low back pain. Proper diagnosis is required for appropriate intervention to provide optimal benefits. From simple trigger point injections for muscular pain to a highly complex intervention such as a spinal cord stimulator are very effective if chosen properly. The aim of this article is to provide the reader with a comprehensive reading for treatment of lower back pain using interventional modalities.

Evidence Acquisition:

Extensive search for published literature was carried out online using PubMed, Cochrane database and Embase for the material used in this manuscript. This article describes the most common modalities available to an interventional pain physician along with the most relevant current and past references for the treatment of lower back pain. All the graphics and images were prepared by and belong to the author.

Results:

This review article describes the most common modalities available to an interventional pain physician along with the most relevant current and past references for the treatment of lower back pain. All the graphics and images belong to the author. Although it is beyond the scope of this review article to include a very detailed description of each procedure along with complete references, a sincere attempt has been made to comprehensively cover this very complex and perplexing topic.

Conclusion:

Lower back pain is a major healthcare issue and this review article will help educate the pain practitioners about the current evidence based treatment options.

Radiological and Radionuclide Imaging of Degenerative Disease of the Facet Joints

The facet joint has been increasingly implicated as a potential source of lower back pain. Diagnosis can be challenging as there is not a direct correlation between facet joint disease and clinical or radiological features. The purpose of this article is to review the diagnosis, treatment, and current imaging modality options in the context of degenerative facet joint disease. We describe each modality in turn with a pictorial review using current evidence. Newer hybrid imaging techniques such as single photon emission computed tomography/computed tomography (SPECT/CT) provide additional information relative to the historic gold standard magnetic resonance imaging. The diagnostic benefits of SPECT/CT include precise localization and characterization of spinal lesions and improved diagnosis for lower back pain. It may have a role in selecting patients for local therapeutic injections, as well as guiding their location with increased precision.

Computational psychological study of the Brief Scale for Psychiatric Problems in Orthopaedic Patients (BS-POP) for patients with chronic low back pain: verification of responsiveness

BACKGROUND

We developed the Brief Scale for Psychiatric Problems in Orthopaedic Patients (BS-POP, physician and patient versions) and have previously shown that the BS-POP is reliable and has construct validity, criterion validity, and reproducibility. The present study aimed to proactively verify the responsiveness of the BS-POP with regard to chronic low back pain (LBP) patients.

METHODS

The study subjects included 193 chronic LBP patients (81 males, 112 females; mean age 62 years) who had suffered from persistent LBP for ≥3 months. During the first test (before the treatment), the BS-POP, the Minnesota Multiphasic Personality Inventory (MMPI), the Profile of Mood States (POMS), the 36-item Short-form Health Survey version 2 (SF-36 v2), and the Roland-Morris Disability Questionnaire (RDQ) were conducted. The BS-POP, POMS, SF-36 v2, and RDQ for the third test were conducted (4-6 weeks after treatment) on all patients who had participated in the first test to determine the responsiveness of the BS-POP. The responsiveness of the BS-POP was investigated statistically.

RESULTS

The total crude BS-POP scores were significantly lower for both physician and patient versions in the third test than in the first test. Moreover, the crude RDQ scores and SF-36 v2 items, physical functioning (PF), bodily pain (BP), MH, VT, and GH, and POMS items, tension-anxiety (T-A), D, F, and confusion (C) improved significantly, confirming responsiveness to treatment.

DISCUSSION

The present findings indicate that the BS-POP possesses sufficient responsiveness from a computational psychology perspective. The BS-POP constitutes a tool enabling orthopaedists to easily identify psychiatric problems in orthopaedic patients.

No Differences in Outcomes in People with Low Back Pain Who Met the Clinical Prediction Rule for Lumbar Spine Manipulation When a Pragmatic Non-thrust Manipulation Was Used as the Comparator

PURPOSE

To investigate differences in pain and disability between patients treated with thrust manipulation (TM) and those treated with non-thrust manipulation (NTM) in a group of patients with mechanical low back pain (LBP) who had a within-session response to an initial assessment and met the clinical prediction rule (CPR).

METHODS

Data from 71 patients who met the CPR were extracted from a database of patients in a larger randomized controlled trial comparing TM and NTM. Treatment of the first two visits involved either TM or NTM (depending on allocation) and a standardized home exercise programme. Data analysis included descriptive statistics and a two-way ANOVA examining within- and between-groups effects for pain and disability, as well as total visits, total days in care, and rate of recovery.

RESULTS

No between-group differences in pain or disability were found for NTM versus TM groups (p=0.55), but within-subjects effects were noted for both groups (p<0.001).

CONCLUSIONS

This secondary analysis suggests that patients who satisfy the CPR benefit as much from NTM as from TM.

Safety of lumbar spine radiofrequency procedures in the presence of posterior pedicle screws: technical report of a cadaver study

OBJECTIVE

To determine whether the thermal energy associated with lumbar spine radiofrequency neurotomy (RFN) performed near titanium and stainless steel pedicle screws is conducted to the pedicle screws or adjacent tissues, or both, thus introducing potential for thermal damage to those tissues.

DESIGN

Cadaver study.

SETTING

Cadaver laboratory equipped with fluoroscopy, surgical spine implements, and radiofrequency generator.

SUBJECTS

No live human subject; a fresh frozen (and thawed) cadaver torso was used for the study.

METHODS

Titanium and stainless steel pedicle screws were placed in the lumbar spine of a fresh frozen cadaver torso with real-time fluoroscopic guidance. Conventional RFN cannula placement was performed at the level of pedicle screws and a control (nonsurgically altered) lumbar level. Neurotomy was performed with conventional radiofrequency lesioning parameters. Temperatures were recorded at multiple sites through thermistor probes.

RESULTS

Direct contact of the radiofrequency cannula with the pedicle screws during conventional RFN produced a substantial increase in temperature in the surrounding soft tissues. A small increase in temperature occurred at the same sites at the control level.

CONCLUSIONS

Titanium and stainless steel pedicle screws are capable of sustaining large increases in temperature when the radiofrequency probe comes in contact with the screw. These results are suggestive that pedicle screws could serve as a possible source of tissue heating and thermal injury during RFN.

Effectiveness of Repeated Radiofrequency Neurotomy for Facet joint Syndrome after Microscopic Discectomy

OBJECTIVE

Postoperative facet joint syndrome requiring radiofrequency neurotomy (RFN) is a relatively common problem following microscopic discectomy. However, the efficacy of repeated RFN after microscopic discectomy has not been clearly documented. The purpose of this study was to determine the success rate and symptom-free duration of repeated RFN for facet joint syndrome after microscopic discectomy.

METHODS

Medical records from 56 patients, who had undergone successful initial RFN following microscopic discectomy, experienced recurrence of pain, and subsequently had repeated RFN, were reviewed and evaluated. Responses of repeated RFN were compared with initial radiofrequency neurotomy for success rates and duration of relief. The criterion for RFN to be successful was defined as greater than 50% relief from pain and sufficient satisfaction of patients with prior RFN to have repeated RFN.

RESULTS

Fifty-six patients (41 women and 15 men; mean age=48 years) had repeated RFNs, which were successful in all except three patients. RFN denervated three bilateral segments (L3-L4, L4-L5, and L5-S1) in all patients. Mean duration of relief after initial RFN was 9.2 months (range 3-14). The mean duration of relief after secondary RFN in 53 patients was 9.0 months (range 4-14). The success rates and duration of relief remained consistent after subsequent RFNs.

CONCLUSION

Repeated RFN for lumbar facet joint pain after microscopic discectomy is an effective palliative treatment. It provided a mean duration of relief of 9.0 months and >94% success rate.

Percutaneous radiofrequency facet joint denervation with monitoring of compound muscle action potential of the multifidus muscle group for treating chronic low back pain: a preliminary report

STUDY DESIGN

A retrospective review.

OBJECTIVE

The aim of this study was to study the effectiveness of percutaneous radiofrequency neurotomy of facet joints by monitoring compound muscle action potentials (CMAPs) of the multifidus muscle group as an objective index of treatment efficacy.

SUMMARY OF BACKGROUND

Percutaneous radiofrequency neurotomy of the medial branches of the dorsal rami of the lumbar nerves is a widely accepted treatment for chronic lumbar intervertebral joint pain. However, its success rate has varied in different studies because an objective method for evaluating the facet joint denervation is lacking.

METHODS

Fifty-five patients (age range, 19-76 y; mean age, 55 y) with low back pain persisting for ≥3 months, in whom facet block and/or block of the medial branch of the dorsal ramus were only temporarily effective, were included. The Japanese Orthopaedic Association (JOA) scoring system for back pain was used for clinical assessment. JOA scores were measured before treatment and 1 week, 3 months, 6 months, and 12 months afterward. The improvement rate was calculated with ≥40% improvement rate defined as successful, and the success rate was subsequently evaluated.

RESULTS

The patient success rate was 75% (41/55) at 1 week, 71% (39/55) at 3 months, 60% (33/55) at 6 months, and 51% (28/55) at 12 months after treatment. Two cases had minor postoperative complications, which were localized burning pain lasting <1 week at the site of electrode insertion.

CONCLUSIONS

Our results suggest that percutaneous radiofrequency facet joint denervation with CMAPs monitoring is a safe, long-lasting, and effective treatment for chronic facet joint pain. CMAP monitoring may be useful as an objective index for facet denervation.

Endoscopically guided foraminal and dorsal rhizotomy for chronic axial back pain based on cadaver and endoscopically visualized anatomic study

BACKGROUND

Conventional fluoroscopically guided continuous radiofrequency (CRF) and pulsed Radiofrequency (PRF) lesioning of the medial branch, dorsal ramus, a standard technique to treat facet pain, is compared to an endoscopic visually guided technique. The endoscopic technique (Figure 1) is designed to ablate a larger area of the transverse process where the medial branch crosses to innervate the facet. Endoscopically guided visualization provides confirmation of nerve ablation or transection in the most common location of the branches of the dorsal ramus innervating the facet joint. Fig. 1 Surgical setup for ablation of the medial, intermediate and lateral branches of the dorsal ramus.

MATERIALS AND METHOD

A retrospective non randomized study of 50 initial patients assessed the efficacy of endoscopic rhizotomy. Patients with lumbar spondylosis and facet arthrosis who had at least 50% pain relief by medial branch blocks met the inclusion criteria for the visualized, surgically directed endoscopic technique. A specially designed cannula and endoscope (Richard Wolf, GmBh) (Figure 2) was developed specifically for this purpose. After completion of the initial 50 patient pilot study in 2005, utilizing a low-temperature, ultra-high frequency (1.7-4.0 MHz) bipolar energy radiofrequency source (Elliquence Int, Hewlett, NY) that demonstrated efficacy, 400 subsequent patients were added to this retrospective study by May 2013. The surgical technique refinement was guided by cadaveric variations observed from additional cadaver dissections (Figure 3) and endoscopic visualization of foraminal nerves that revealed variable locations of the dorsal ramus, including the medial branch. The anatomic variations supported a need for visualized rhizotomy. The inclusion criteria also involved increasing the percentage of back pain relief from medial branch blocks to a base of 75% estimated improvement in order to overcome the variable subjectiveness of a 50% improvement threshold that served to disappoint a small percentage of patients who overestimated the reported 50% improvement in hopes that they would qualify for the endoscopic guided procedure. Fig. 2 Richard Wolf YESS Rhizotomy Set. The cannulas, endoscope, bitip and surgical bipolar RF probes by Elliquence are configured ergonomically to provide excellent focal length imaging to keep image in focus with the endoscope scope resting on cannula. The bitip probe cuts tissue, and the RF probe thermally ablates tissue efficiently.Fig. 3 Cadaver dissection of the dorsal ramus and its branches out- lining the areas where branches of the dorsal ramus may be visualized and ablated before it reaches the facet joint.

RESULTS

At one year follow-up in the initial study design, VAS improved 6.2-2.5, and ODI 48-28. All patients had VAS improvement equal or greater than injection. The results remained constant with additional surgical cases that continued to improve when technique and visualized rhizotomy allowed for greater surgical exploration and ablation of the targeted zone where more than just the medial branch could be ablated. Approximately 10 percent of the patients returned at one and two year follow-up with mild recurrence of their axial back pain, but none to the original level of pain. Additional rhizotomy of the upper lumbar facets provided additional relief in selected patients.

CONCLUSIONS / LEVEL OF EVIDENCE 3

The cadaver studies demonstrated considerable variability in the location of the medial and lateral branches of the dorsal ramus. Variability was most common cephalad to L3-4. The dorsal ramus and its nerve branches can also be visualized in the foramen ventral to the intertransverse ligament. Neuromas and entrapment of the dorsal ramus has been identified endoscopically, and confirmed by H and E slides (Figure 4). In the upper lumbar spine, we were not able to find the medial branch to the facets consistently at same location. The nerve to the facet joint did not always cross the transverse process. Some branches enter the facet joint before crossing the transverse process adjacent to the tip of the SAP (Figure 5). The nerve can be mistaken for a furcal nerve or foraminal ligament. Nerve Ablation at above L3-4 levels may require lesioning of the dorsal ramus or targeting the nerve innervation on the facet wall, pedicle or capsule. Fig. 4 This H and E slide of the biopsied specimen is consistent with a peripheral nerve fiber.Fig. 5 This foraminal view of a branch of the dorsal ramus is in the foramen at the level of the SAP. The nerve runs along the ventral lateral aspect of the superior facet to the tip, and can also run in the vicinity of the foraminal ligament. Endoscopic rasps, trephines, kerrisons, and burrs can be used for foraminoplasty. The nerve should be preserved, if possible, but transection of a branch of the dorsal ramus contributes to axial back pain relief. Branches of the dorsal ramus originates in the foramen before exiting to traverse the transverse process. These nerves are difficult to differentiate from furcal nerves arising from the spinal nerves. Palpating the nerve using local anesthesia can sometimes demonstrate a pain response, but not always, depending on the level of sedation and anesthetic use.

CLINICAL RELEVANCE

Endoscopically guided facet rhizotomy provides more consistent ablation of the medial and lateral branches of the lumbar dorsal ramus compared to radiographically guided pulsed radiofrequency. The variations in the location of facet innervation can explain the variability of clinical results in fluoroscopically guided RF lesioning. This observation dictates a need for visually guided MIS procedure for best results.

Minimally invasive facet restoration implant for chronic lumbar zygapophysial pain: 1-year outcomes

BACKGROUND

The zygapophysial (facet) joint is the primary pain generator in one third of chronic low back pain cases. Current treatment options include temporarily palliative nonsurgical approaches, facet injections, radiofrequency denervation, and, rarely, lumbar arthrodesis. The purpose of this study was to assess the safety and effectiveness of a minimally invasive implant intended to restore facet joint function in patients with chronic lumbar facetogenic pain.

METHODS

This prospective, multi-center feasibility study enrolled patients with confirmed lumbar facetogenic joint pain at 1 or 2 levels who underwent at least 6 months of unsuccessful nonoperative care. Patients received a minimally invasive implant (Glyder® Facet Restoration Device, Zyga Technology, Inc., Minnetonka, MN) intended to restore facet joint function while preserving the native anatomy. Main outcomes included back pain severity using a visual analogue scale, back-specific disability using the Oswestry Disability Index (ODI), and adverse events adjudicated by an independent Clinical Events Committee.

RESULTS

Of 40 enrolled patients, 37 patients received the facet restoration implant and 34 patients had complete 1-year follow-up data available. Over the 1-year follow-up period, back pain severity decreased 41% and ODI decreased 34%, on average. Freedom from a device- or procedure-related serious adverse event through 1 year was 84%. Implant migration was observed in 3 patients and implant expulsion from the facet joint occurred in 3 patients. In total, 2 (5.4%) patients underwent implant removal through 1 year post-treatment.

CONCLUSIONS

A minimally invasive facet restoration implant is a promising treatment option in select patients with chronic lumbar zygapophysial pain who have exhausted nonsurgical treatments, with therapeutic benefit persisting at 1 year follow-up.