Factors predicting success and failure for cervical facet radiofrequency denervation: a multi-center analysis

BACKGROUND AND OBJECTIVES: The concept of radiofrequency denervation has recently come under question in light of several studies showing minimal to no benefit. One possibility proposed for these negative outcomes is poor selection criteria. Unlike virtually all other spine interventions, the factors associated with success and failure for cervical facet denervation have yet to be determined. The purpose of this study is to determine which demographic, clinical and treatment factors are associated with cervical facet radiofrequency denervation outcomes. METHODS: Data were garnered from 3 academic medical centers on 92 patients with chronic neck pain who underwent radiofrequency denervation after a positive response to diagnostic local anesthetic blocks. Success was defined as at least 50% pain relief lasting at least 6 months. Variables evaluated for their association with outcome included age, sex, duration of pain, opioid use, pain referral pattern, paraspinal tenderness, pain exacerbated by extension/rotation, magnetic resonance image abnormalities, diabetes, smoking, scoliosis, obesity, prior surgery, and levels treated. RESULTS: The only clinical variable associated with success was paraspinal tenderness. Factors associated with treatment failure included radiation to the head, opioid use, and pain exacerbated by neck extension and/or rotation. CONCLUSIONS: Selecting patients based on key clinical variables may increase the chance of treatment success for cervical facet radiofrequency denervation.     

Percutaneous radiofrequency facet denervation in low-back and extremity pain

Summary The present series includes 47 patients (35 females 12 males) with an average observation time of 8 months after percutaneous lumbar facet denervation by radiofrequency electrocoagulation. All patients had static and kinetic lumbar pain; 90% of them had pain radiating into the legs. None had clinical or radiologic (radiculography and/or CT scan) evidence of a lumbar disc herniation, and all had exhausted conservative therapy. All but one had provocation of their habitual pain on arthrography of the relevant intervertebral lumbar joints and/or on intraoperative stimulation prior to electrocoagulation. 22/47 of the patients had no immediate or late beneficial effect of the electrocoagulation. Eight of the remaining 25 patients had satisfactory relief of pain at follow-up. The failures included all patients with previous multiple lumbar operations except for three.Part of this read as paper at the 35th Annual Meeting of the Scandinavian Neurosurgical Society, June 1–4, 1983, Helsinki, Finland.     

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.

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

STUDY DESIGN: A prospective double-blind randomized trial in 31 patients. OBJECTIVES: To assess the clinical efficacy of percutaneous radiofrequency denervation of the lumbar zygapophysial joints in reducing pain, functional disability, and physical impairment in patients with back pain originating from the lumbar zygapophysial joints. SUMMARY OF BACKGROUND DATA: Chronic low back pain is a major health problem in the industrialized world. A treatment option is percutaneous radiofrequency denervation of the lumbar zygapophysial joints. Its clinical efficacy has never been formally tested in a controlled trial. METHODS: Thirty-one patients with a history of at least 1 year of chronic low back pain were selected on the basis of a positive response to a diagnostic nerve blockade and subsequently randomly assigned to one of two treatment groups. Each patient in the radiofrequency treatment group (15 patients) received an 80 C radiofrequency lesion of the dorsal ramus of the segmental nerve roots L3, L4, and L5. Patients in the control group (n = 16) underwent an the same procedure but without use of a radiofrequency current. Both the treating physician and the patients were blinded to the group assignment. Before treatment, physical impairment, rating of pain, the degree of disability, and quality of life were assessed by a blinded investigator. RESULTS: Eight weeks after treatment, there were 10 success patients in the radiofrequency group (n = 15) and 6 in the sham group (n = 16). The unadjusted odds ratio was 3.3 (P = 0.05, not significant), and the adjusted odds ratio was 4.8 (P < 0.05, significant). The differences in effect on the visual analog scale scores, global perceived effect, and the Oswestry disability scale were statistically significant. Three, 6, and 12 months after treatment, there were significantly more success patients in the radiofrequency group compared with the sham group. CONCLUSIONS: Radiofrequency lumbar zygapophysial joint denervation results in a significant alleviation of pain and functional disability in a select group of patients with chronic low back pain, both on a short-term and a long-term basis.     

Radiographic fusion rate after implantation of facet bone dowels

Background contextAchieving a posterolateral fusion in conjunction with performing decompressive laminectomies can prevent recurrence of stenosis or worsening of spondylolisthesis. Facet bone dowels have been introduced and marketed as a less invasive alternative to pedicle screws. Surgeons have been placing them during lumbar laminectomy surgery and coding for intervertebral biomechanical device and posterolateral fusion. These bone dowels have also been placed percutaneously in outpatient surgery centers and pain clinics for facet-mediated back pain.PurposeTo describe fusion outcomes in patients who underwent facet bone dowel placement.Study design/settingRetrospective analysis of a single center's experience.Patient sampleNinety-six patients comprise the entire cohort of patients who underwent facet bone dowel implantation at our institution with adequate postoperative imaging to determine fusion status.Outcome measuresFusion rates as determined on postoperative computed tomography (CT) scans and dynamic lumbar X-rays if CT is not available.MethodsThreaded facet bone dowels in this study were placed according to the manufacturer's recommended methods. The bone dowels were placed after open exploration of the facet complex or percutaneously through a tubular retractor on the contralateral side from a microdiscectomy or synovial cyst resection. The most recent available postoperative imaging was reviewed to determine fusion status.ResultsOf 96 patients in our series, 6 (6.3%) had a fusion seen on CT and 4 did not exhibit any movement on dynamic lumbar X-rays for a total fusion rate of 10.4% (10/96). Eighty-six (89.6%) patients were shown on imaging to not have a solid fusion either by visualizing a patent facet joint on CT or measurable movement between the flexion and the extension lumbar X-rays.ConclusionsThis article is mainly intended to question whether the implantation of facet bone dowels can produce a solid fusion radiographically. In our experience, the placement of facet bone dowels does not equal the time, skill, or attention to detail that is necessary for a posterolateral lumbar arthrodesis, and our follow-up radiographic studies clearly demonstrate an inadequate fusion rate.     

Radiofrequency lumbar facet denervation: a comparative study of the reproducibility of lesion size after 2 current radiofrequency techniques

BACKGROUND AND OBJECTIVES: Radiofrequency facet denervation procedures are widely used for the treatment of chronic low-back pain. Currently, both temperature-controlled and voltage-controlled techniques are used. In this combined in vivo and in vitro study, the electrophysiologic consequences and the effects on lesion size of these techniques were determined. METHODS: Thirty-three patients were randomly assigned to receive a lumbar radiofrequency facet denervation by using either temperature-controlled (80 degrees C, 60 seconds) or voltage-controlled (20 V, 60 s) mode. Electrophysiologic parameters in both groups during radiofrequency lesioning were registered. Observed differences between electrodes were quantified and interpreted, using lesion-size data from egg-white experiments. RESULTS: Seventeen patients in the temperature group were treated with a total of 55 radiofrequency lesions, all considered technically adequate. In the voltage-controlled group, 16 patients received 63 lesions. Of these, 44 (69.8%) procedures were found to be technically inadequate. Voltage-controlled radiofrequency lesioning resulted in uncontrollable fluctuations of temperature, with resultant uncontrollable variations in lesion size. Temperature-controlled mode created reproducible lesion sizes. CONCLUSIONS: There is no consistent relation between voltage and the temperature obtained during radiofrequency lumbar facet denervation. Temperature-controlled radiofrequency lesioning is preferred to create reproducible lesion sizes.     

Factors determining the success of radiofrequency denervation in lumbar facet joint pain: a prospective study

Background and aims  

Radiofrequency denervation (RF) of the lumbar facet joints has been shown to be effective in well-selected patients. However, long-term success varies between studies. We evaluated the influence of selected psychosocial and constitutional factors on the outcome of RF, expressed as the duration of pain relief.     

Morphological changes of cervical facet joints in elderly individuals

To better understand the role of facet joint degeneration in chronic neck and back pain epidemiological and morphological data are needed. For the cervical spine, however, such data are rare. Therefore, the aim of this study was to determine the degree of cartilage degeneration of cervical facet joints with respect to spinal level and age, to investigate whether any region of the joint surface is more often affected by degeneration and to determine the localisation of osteophytes. A total of 128 left-sided facet surfaces from 15 fresh frozen cervical spine specimens (59-92 years) including in maximum C2-C7 were inspected in a way to ensure a direct comparability to data reported for the lumbar spine. First, the macroscopic degree of cartilage degeneration was determined and correlated to spinal level and age. Then, each facet surface was divided into five regions (anterior, posterior, lateral, medial and central) to check whether cartilage degeneration occurs more often in any of these regions. Finally, the localisation of osteophytes was determined. The results showed that the mean degree of cartilage degeneration was 2.8 (+/-0.6) on a scale from Grade 1 (no degeneration) to 4 (severe degeneration). None of all 128 facet surfaces was classified as Grade 1. All spinal levels had about the same degree of degeneration (in mean 2.5-3.0). The youngest age group (<70 years) had a somewhat lower degree of degeneration (2.6) than the oldest (> or = 90 years) (3.1). Cartilage defects were found all over the joint surfaces, none of the five regions was more often affected than the others. Least osteophytes were found on the medial border of the facet joints. In conclusion, the prevalence of cervical facet joint degeneration is probably very high in individuals aged 50 years and more, with a tendency to increase in severity with age. All levels of the middle and lower cervical spine were affected to almost the same degree, whereas in the lumbar spine an increase in degeneration towards the lower levels was reported. Also, in the cervical spine in most cases the cartilage was evenly degenerated all over the joint surface while in the lumbar spine certain regions were reported to be affected predominantly.     

肝肿瘤射频消融术后感染性并发症的处理

目的分析肝恶性肿瘤经皮射频消融术(RFA)后感染性并发症的临床特点及处理方法。方法回顾性分析于我科接受RFA治疗的356例肝脏恶性肿瘤患者,其中原发性肝癌296例,肝转移癌60例。对于术后有严重感染表现的患者进行即刻腹部超声和(或)CT增强扫描。明确肝内局部脓肿形成后,采取置管引流、使用抗生素等干预措施,并随访1年。全部脓肿引流液均行细菌学检查并根据药敏结果调整抗生素用药。结果 356例RFA术后共5例患者发生局部严重感染,其中3例为肝脓肿,1例胆汁瘤合并感染,1例为腹壁脓肿。1例肝脓肿患者肝内局部病灶与结肠肝曲形成窦道且经久不愈,经外科手术局部修补+肝内脓肿置管引流后局部及全身症状有所缓解,但于RFA术后8个月死于全身衰竭。1例腹壁脓肿患者经抗感染、置管引流、局部换药处理后局部及全身症状有所缓解,但于RFA术后6个月死于肿瘤进展。1例肝脓肿和1例胆汁瘤合并感染患者经单纯病变部位置管引流+抗生素治疗后临床症状明显缓解,随诊1年达到临床治愈。1例肝脓肿患者经病变部位置管引流+抗生素治疗后,感染灶痊愈,但随访至9个月时死于肝内肿瘤转移导致的多脏器功能衰竭。结论 RFA术后严重感染性并发症并不少见,感染途径可来自肠道菌群逆行感染,Whipple术等导致Oddi括约肌无功能的RFA术后继发严重感染的明确诱因。除根据药敏实验应用敏感抗生素外,及时行脓腔穿刺引流、外科干预等综合治疗是针对RFA术后局部感染性并发症的有效方法。     

The surgical anatomy of thoracic facet denervation

Summary Thoracic percutaneous facet denervation has been employed for the treatment of thoracic zygapophysial joint pain. But the surgical anatomy of this procedure has been assumed to be the same as for lumbar medial branch neurotomy. To establish the anatomical basis for thoracic medial branch neurotomy, an anatomical study was undertaken. Using an X40 dissecting microscope, a total of 84 medial branches from 7 sides of 4 embalmed human adult cadavers were studied.The medial branches of the thoracic dorsal rami were found to assume a reasonably constant course. Upon leaving the intertransverse space, they typically crossed the superolateral corners of the transverse processes and then passed medially and inferiorly across the posterior surfaces of the transverse processes before ramifying into the multifidus muscles. Exceptions to this pattern occurred at mid-thoracic levels (T5–T8). Although the curved course remained essentially the same, the inflection occurred at a point superior to the superolateral corner of the transverse process.At no time during the dissection were nerves encountered crossing the junctions between the superior articular processes and transverse processes which have been the target points advocated for thoracic facet denervation. Rather, the results of this study indicate that the superolateral corners of the transverse processes are more accurate target points.     

Combination therapy of radiofrequency lumbar facet joint denervation and epidural spinal cord stimulation for failed back surgery syndrome

An 81-year-old woman with failed back surgery syndrome (FBSS) was treated using a combination of percutaneous radiofrequency (RF) lumbar zygapophysial joint denervation and epidural spinal cord stimulation (SCS). She had undergone a staged laminectomy for narrowing of the spinal canal from L1 to S1 and degenerative spondylolisthesis at the L3-4 level. Postoperatively, in addition to low back pain (LBP) induced by dynamic motion, she began to experience intractable leg pain with a burning sensation, presumably caused by damage to the cauda equina. She initially underwent RF lumbar zygapophysial joint denervation for the LBP and subsequently underwent SCS via dual electrode leads for the leg pain. This combination therapy of RF denervation and SCS relieved the LBP almost entirely and relieved the leg pain by approximately 50%. The combination of these two minimally invasive interventions is particularly effective for severe leg pain and LBP in elderly patients or medically compromised cases with contraindications against general anesthesia, as well as in patients with FBSS.     

Tensile stretching of cervical facet joint capsule and related axonal changes

This study examines axonal changes in goat cervical facet joint capsules (FJC) subjected to low rate loading. Left C5–C6 FJC was subjected to a series of tensile tests from 2 mm to failure using a computer-controlled actuator. The FJC strain on the dorsal aspect was monitored by a stereo-imaging system. Stretched (n = 10) and unstretched (n = 7) capsules were harvested and serial sections were processed by a silver impregnation method. The mean peak actuator displacement was 21.3 mm (range: 12–30 mm). The average peak strain encompassing various regions of the capsule was 72.9 ± 7.1%. Complete failure of the capsule was observed in 70% of the stretched capsules. Silver impregnation of the sections revealed nerve fibers and bundles in all the regions of the capsule. A blinded analysis of digital photomicrographs of axons revealed a statistically significant number of swollen axons with non-uniform caliber in stretched FJCs. Axons with terminal retraction balls, with occasional beaded appearance or with vacuolations were also observed. Stretching the FJC beyond physiological range could result in altered axonal morphology that may be related to secondary or delayed axotomy changes similar to those seen in central nervous system injuries where axons are subjected to stretching and shearing. These may contribute to neuropathic pain and are potentially related to neck pain after whiplash events.     

Percutaneous facet denervation in chronic thoracic spinal pain

Summary In 40 patients with chronic thoracic spinal pain of more than 12 months duration which failed to respond to conservative treatment and with a previous evaluation by specialists, mainly neurologists and orthopaedic surgeons, the diagnosis of facet syndrome was made. This diagnosis was based on clinical criteria and a transient positive response to a prognostic blockade of the medial branch of the dorsal ramus of the thoracic spinal nerve. They were selected to undergo percutaneous radiofrequency denervation of the facet joints. The short and long-term results of 51 percutaneous thoracic facet denervations in 40 patients are described. After 2 months, 19 patients (47.5%) were pain-free, 14 patients (35%) had more than 50% pain-relief, and 7 patients (17.5%) had no relief. After a follow-up of 18–54 (average 31) months in 36 cases (3 patients had died because of malignancy, and 1 had undergone a spinal fusion), 16 patients (44%) were pain-free, 14 patients (39%) had more than 50% pain-relief and in 6 cases (17%) the result was poor. Adverse effects consisted of postoperative pain in 5 patients (12.5%). When conservative treatment fails, percutaneous thoracic facet denervation can be a safe and beneficial therapy in chronic thoracic spinal pain originating from the facet joints.     

Alternative denervation using laser irradiation in lumbar facet syndrome

BACKGROUND AND OBJECTIVE: Facet syndrome is persistent low back pain that might be treated with some surgical interventions. The target of surgical techniques is the transverse process bases where the medial nerve branches innervated the facet. However, highly variable success rates have been demonstrated in different series. STUDY DESIGN/MATERIALS AND METHODS: We carried out laser denervation to the dorsal surface of the facet capsule, where it is richly innervated with medial nerve branches. RESULTS: One year after laser denervation, 17 patients (81%) experienced complete or greater than 70% pain reduction in all 21 patients. Among the six patients who had previously undergone spinal surgery, two (33.3%) experienced successful pain relief. Overall, in four patients (19%), the response to laser denervation at 1-year follow-ups was not successful. CONCLUSION: The dorsal surface of the facet capsule might be a more preferable target for facet denervation.