Radio-Frequency Lesioning
What is radio-frequency lesioning?
Radio-frequency lesioning involves the destruction or long-term block of small nerves. The radio-frequency unit allows heat to be generated in nerve tissue sufficient to either destroy or deactivate the nerve.
What are facet nerves?
Facet nerves are small nerves that branch out from larger spinal nerves exiting the spine. These nerves contain mostly sensory information. The nerves supply the facet joints, ligaments, skin, and small muscles at each segment. These are NOT the nerves that are responsible for movement of the extremities and sensation in the extremities.
How is the procedure performed?
The procedure is performed under local anesthetic with sedation. Fluoroscopic control (x-ray guidance) is used to help ensure safe and correct placement. In addition, stimulation of the nerves is also used to identify the location of the needle tip. If there is stimulation down an extremity, the needle is moved to a different location before lesioning. When patients feel stimulation locally and x-ray position is acceptable, lesioning is then performed.
Is the procedure painful?
Because the procedure is performed while the patient is awake but sedated, you may feel some uncomfortable sensations at times. However, most patients will receive medications such as Versed (a sedative) and Demerol (a narcotic). During lesioning, most patients will experience pain for about 10 – 15 seconds. Post procedure, patients may also have some injection site tenderness for up to two weeks. Patients are given a supply of narcotic pain medications following the procedure.
Which patients are candidates for radio-frequency lesioning of facet nerves?
Patients that have been shown to have pain originating from the facet joints are candidates for this procedure. Patients should have had at least two facet injections that gave significant reduction of pain. At least two diagnostic injections on separate occasions are required to rule out a placebo response.
How long it does its take for this procedure to work?
Many patients experience relief immediately following the procedure. However, because of injection site soreness, some patients may not have relief for up to 2 weeks.
What chance is there that the procedure will work?
Studies have shown that there is a 50% chance of significant pain relief following the procedure as far out as two years. About half of the remaining patients get benefit for shorter periods of time and some patients do not get any benefit from this procedure. The reason why some patients do not improve is probably because diagnostic blocks are not 100% specific.
What studies support the use of radio-frequency lesioning?
The following is a list of references and brief descriptions of studies that used percutaneous radio-frequency in the treatment of the lower back and neck pain:
1. VanKleef et al. Randomized Trial of Radiofrequency Lumbar Facet Denervation for Chronic Lower Back Pain. Spine 1999, 24: 1937 -- 42.
This was a prospective randomized trial. There were 31 patients that completed the study for 12 months. There was marked overall improvement in the radiofrequency group versus the control (sham) group at eight weeks, six months, and 12 months follow-up.
2. Gallagher et al. Radiofrequency Facet Denervation in the Treatment of Lower Back Pain. The Pain Clinic 1994, 7:193 -- 8.
There were 41 patients in this six-month double blinded, randomized controlled study. There was 50% reduction in pain scores at one month and six-month periods following radiofrequency treatment.
3. Dreyfuss et al. Efficacy and Validity of Radiofrequency Neurotomy for Chronic Lumbar Zygapophyseal Joint Pain. Spine 2000, 25: 1270 -- 77.
This was a 12 month prospective study of the 15 patients chosen from a sample of 170 patients that participated in a double block paradigm. In 14 out of 15 patients there was "dramatic reduction" of pain at six weeks. There was a 90% reduction in pain scores for 60% of the patients. There was one year of relief (defined as at least a 60% reduction in pain) for 87% of the patients.
4. Chos et al. Percutaneous Radio-Frequency Lumbar Facet Rhizotomy in Mechanical Lower Back Pain Syndrome. Stereotactic Functional Neurosurgery 1997, 68: 212 -- 217.
This study involved 324 patients that were followed between 6 -- 51 months. A 4 point grading system (excellent, good, fair, poor) was utilized for assessment. Results indicated that 51% had an excellent outcome, 45% had good outcome, 4% had a fair outcome, and one of the patients reported worsening of pain following facet radio-frequency.
5. North et al. Radio-Frequency Lumbar Facet Denervation: Analysis of Prognostic Factors. Pain 1994, 57: 77 -- 83.
This was a retrospective case series of 8 to patients that were followed on the average of 3.2 years. At least 50% relief was obtained in 45% of the patients who had facet denervation.
6. Koning and Mackie. Percutaneous Radio-Frequency Facet Denervation in Low Back Pain. The Pain Clinic 1994, 7: 199 -- 204.
There were 51 patients followed in 45% had reduction of pain six weeks following the treatment.
7. Sapir, DA et al. Radio-Frequency Medial Branch Neurotomy in Litigant and Nonlitigant Patients with Cervical Whiplash: A Prospective Study. Spine 2001 June 15; 26 (12) E 268 -- 273.
This is a clinical trial involving 60 cervical whiplash patients who remained symptomatic after 20 weeks of conservative management. Forty-six patients completed the study. Overall reduction and cervical whiplash symptoms and visual analogue pain scale was significantly reduced immediately following treatment in the nonlitigant and litigant respectively at 2.0 and 2.5. One year follow-up scores for nonlitigant and litigant populations showed 2.9 and 4.0 reductions in pain scores respectively.
8. Lord, SM et al. Percutaneous Radio-Frequency Neurotomy for Chronic Cervical Zygapophyseal Joint Pain. New England Journal of Medicine December 5, 1996 volume 335: 1721 -- 1726.
This was a randomized double-blind trial comparing radio-frequency neurotomy to a control treatment placing needles without radio-frequency. Twenty-four patients were included in the trial. The source of pain had been identified with the use of double-blind placebo-controlled local anesthetic blocks of the cervical median nerves. The meantime the last for pain returned to at least 50% of the preoperative level was 263 days in the active treatment group and eight days in the control group.
Are there any risks or complications from the procedure?
Because this procedure is performed under x-ray control and patients are awake, the risk of large nerve injury is very small. Nerve stimulation is performed prior to lesioning so that large nerves that supply the extremities are not damaged. X-ray control ensures that the needle tip is in a safe location. Patients will typically experience some injection site pain following the procedure and oral narcotic medications will be dispensed over this period of time. Patients may also have some numbness of the skin overlying the injection site.
How long does pain relief last following the procedure?
Only small peripheral sensory nerves are lesioned with this procedure. These nerves do have the capacity to grow back. Patients may require repeat lesioning as early as 6 months but some may also have long-term relief as well.
What if the procedure does not work?
In this case, it may be that the pain generator is a different location other than that supplied by the facet nerves. The patient should be re-evaluated and other diagnostic interventions should be considered.
Does insurance cover this procedure?
Most insurance companies cover radio-frequency. However, in some cases preauthorization may be required. Your insurance coverage may vary depending on your specific plan and policy.
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