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Percutaneous lumbar zygapophysial (Facet) joint neurotomy using radiofrequency current, in the management of chronic low back pain: a randomized double-blind trial.
[SIZE=-1]Nath S, Nath CA, Pettersson K.[/SIZE]
[SIZE=-1]Spine. 2008 May 20;33(12):1291-7. PMID: 18496338[/SIZE]
STUDY DESIGN: A randomized controlled study of percutaneous radiofrequency neurotomy was conducted in 40 patients with chronic low back pain (20 active and 20 controls).
OBJECTIVE: The aim of the study was to evaluate the possible beneficial effect of percutaneous radiofrequency zygapophysial joint neurotomy in reducing pain and physical impairment in patients with pain from the lumbar zygapophysial joints, selected after repeated diagnostic blocks.
SUMMARY OF BACKGROUND DATA: Facet or zygapophysial joint pain may be one of the causes of chronic low back pain and may be treated by a percutaneous radiofrequency denervation. Patients may possibly be identified by a positive diagnostic block. These blocks need to be repeated as false positive responses to single blocks occur.In all previous studies patients treated with radiofrequency denervation have been selected after single diagnostic blocks resulting in a varying degree of relief.
METHODS: All patients were examined by an orthopedic surgeon before and 6 months after the treatment (sham or active). Inclusion criteria were 3 separate positive facet blocks. Denervation was achieved by multiple lesions at each level in an effort to provide effective denervation. RESULTS: The active treatment group showed statistically significant improvement not only in back and leg pain but also back and hip movement as well as the sacro-iliac joint test. Pre operative sensory deficit and weak or absent ankle reflex normalized (P < 0.01) and (P < 0.05), respectively. There was significant improvement in quality of life variables, global perception of improvement, and generalized pain.The improvement seen in the active group was significantly greater then that seen in the placebo group with regard to all the above-mentioned variables.None of our patients had any complication other than transient postoperative pain that was easily managed.
CONCLUSION: Our study indicates that radiofrequency facet denervation is not a placebo and could be used in the treatment of carefully selected patients with chronic low back pain.
Point of View
Bogduk, Nikolai MD, PhD, DSc, FFPM(ANZCA)
[SIZE=-1]Spine. 2008 May 20;33(12):1298[/SIZE]
In an outcome study, Dreyfuss et al demonstrated how good the outcomes could be from lumbar medial branch neurotomy. Yet that study was variously chastised: for having no controls; for being highly selective in its recruitment criteria; for enrolling only a tiny proportion of potential patients; and, therefore, for being too small a study. Subsequently, systematic reviews demanded randomized controlled trials of lumbar medial branch neurotomy, but none of the controlled trials that followed used correct surgical technique for this procedure; and none selected patients on the basis of controlled diagnostic blocks.
Dr. Nath answered the call for studies. His is the first study, since Dreyfuss et al, to use controlled diagnostic blocks to select patients, and the first to use correct technique. But Dr. Nath did something unusual. He did not select ideal patients, free of comorbidity, with already good function, and no depression. He drew his patients from a pain clinic population. His patients had other problems; but they were, nevertheless, able to identify a component of their pain that was completely relieved by controlled medial branch blocks. It was this pain that Dr. Nath treated in a placebo-controlled trial of lumbar medial branch neurotomy.
Dr. Nath should be commended for his industry both in mounting and concluding a placebo-controlled trial. His results clearly show that the effects of lumbar medial branch neurotomy cannot be attributed, ex cathedra, to placebo effects. The effects are genuine.
What may be difficult for readers to appreciate is that this treatment did not relieve every pain that Dr. Nath's patients had. Other pains were not the target of the intervention. Nevertheless, the index pain was relieved, and corroborated by improvements in function.
In this context, Dr. Nath did not validate lumbar medial branch neurotomy as a monotherapy for all patients with back pain, but nor did he set out to do so. For practical purposes, he showed only that medial branch neurotomy could be a complimentary therapy in patients typical of a pain clinic population. For academic purposes, however, his achievement is more profound. In an adventitious manner, he dispelled accusations that lumbar medial branch neurotomy is a placebo.
It will be interesting to see if pundits now complain that Dr. Nath should have recruited highly selected, ideal patients, with pure zygapophysial joint pain, with no comorbidity, and who would be atypical of patients seen in conventional practice.
[SIZE=-1]Nath S, Nath CA, Pettersson K.[/SIZE]
[SIZE=-1]Spine. 2008 May 20;33(12):1291-7. PMID: 18496338[/SIZE]
STUDY DESIGN: A randomized controlled study of percutaneous radiofrequency neurotomy was conducted in 40 patients with chronic low back pain (20 active and 20 controls).
OBJECTIVE: The aim of the study was to evaluate the possible beneficial effect of percutaneous radiofrequency zygapophysial joint neurotomy in reducing pain and physical impairment in patients with pain from the lumbar zygapophysial joints, selected after repeated diagnostic blocks.
SUMMARY OF BACKGROUND DATA: Facet or zygapophysial joint pain may be one of the causes of chronic low back pain and may be treated by a percutaneous radiofrequency denervation. Patients may possibly be identified by a positive diagnostic block. These blocks need to be repeated as false positive responses to single blocks occur.In all previous studies patients treated with radiofrequency denervation have been selected after single diagnostic blocks resulting in a varying degree of relief.
METHODS: All patients were examined by an orthopedic surgeon before and 6 months after the treatment (sham or active). Inclusion criteria were 3 separate positive facet blocks. Denervation was achieved by multiple lesions at each level in an effort to provide effective denervation. RESULTS: The active treatment group showed statistically significant improvement not only in back and leg pain but also back and hip movement as well as the sacro-iliac joint test. Pre operative sensory deficit and weak or absent ankle reflex normalized (P < 0.01) and (P < 0.05), respectively. There was significant improvement in quality of life variables, global perception of improvement, and generalized pain.The improvement seen in the active group was significantly greater then that seen in the placebo group with regard to all the above-mentioned variables.None of our patients had any complication other than transient postoperative pain that was easily managed.
CONCLUSION: Our study indicates that radiofrequency facet denervation is not a placebo and could be used in the treatment of carefully selected patients with chronic low back pain.
Point of View
Bogduk, Nikolai MD, PhD, DSc, FFPM(ANZCA)
[SIZE=-1]Spine. 2008 May 20;33(12):1298[/SIZE]
In an outcome study, Dreyfuss et al demonstrated how good the outcomes could be from lumbar medial branch neurotomy. Yet that study was variously chastised: for having no controls; for being highly selective in its recruitment criteria; for enrolling only a tiny proportion of potential patients; and, therefore, for being too small a study. Subsequently, systematic reviews demanded randomized controlled trials of lumbar medial branch neurotomy, but none of the controlled trials that followed used correct surgical technique for this procedure; and none selected patients on the basis of controlled diagnostic blocks.
Dr. Nath answered the call for studies. His is the first study, since Dreyfuss et al, to use controlled diagnostic blocks to select patients, and the first to use correct technique. But Dr. Nath did something unusual. He did not select ideal patients, free of comorbidity, with already good function, and no depression. He drew his patients from a pain clinic population. His patients had other problems; but they were, nevertheless, able to identify a component of their pain that was completely relieved by controlled medial branch blocks. It was this pain that Dr. Nath treated in a placebo-controlled trial of lumbar medial branch neurotomy.
Dr. Nath should be commended for his industry both in mounting and concluding a placebo-controlled trial. His results clearly show that the effects of lumbar medial branch neurotomy cannot be attributed, ex cathedra, to placebo effects. The effects are genuine.
What may be difficult for readers to appreciate is that this treatment did not relieve every pain that Dr. Nath's patients had. Other pains were not the target of the intervention. Nevertheless, the index pain was relieved, and corroborated by improvements in function.
In this context, Dr. Nath did not validate lumbar medial branch neurotomy as a monotherapy for all patients with back pain, but nor did he set out to do so. For practical purposes, he showed only that medial branch neurotomy could be a complimentary therapy in patients typical of a pain clinic population. For academic purposes, however, his achievement is more profound. In an adventitious manner, he dispelled accusations that lumbar medial branch neurotomy is a placebo.
It will be interesting to see if pundits now complain that Dr. Nath should have recruited highly selected, ideal patients, with pure zygapophysial joint pain, with no comorbidity, and who would be atypical of patients seen in conventional practice.
