ASIPP Practice Guidelines - Pain Physician

Manchikanti et al • ASIPP Practice Guidelines
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level. For intra-articular injection he used 2% lidocaine, 1
mL, and 0.5% bupivacaine, 1 mL, along with a 20-mg
methylprednisolone acetate suspension. The two treatments
were equally effective but were disappointing in their therapeutic
effect. A total of 58% of patients in each group
demonstrated significant pain relief at 1-month follow-up.
Based on this report, as a therapeutic measure, posterior
ramus medial branch nerve blockade was proven to be as
effective as intra-articular injection of steroid in low back
pain of probable facet origin, suggesting that facet joint
pain does not have an inflammatory component.
In another study, North et al (377) used diagnostic facet
blocks and incorporated assessment by a disinterested third
party. Following the diagnostic medial branch blocks, 42%
of the patients reported at least 50% relief of pain. Among
40 patients who underwent temporary blocks but did not
undergo radiofrequency denervation, 13% reported relief
of at least 50% at long term follow-up with mean interval
of 3.2 years.
Barnsley and Bogduk (375) studied 16 consecutive patients
with chronic neck pain from motor vehicle accidents and
reported complete or definite relief of their pain in 11 patients.
All of the trials described above face criticism. The randomized
clinical trial by Manchikanti et al (481) is limited
by failure to incorporate a placebo group and to utilize a
major instrument to evaluate the progress. Other studies
by Manchikanti et al (182), Marks et al (380), and Nash
(379) were also limited by failure to incorporate a placebo
group, lack of long term follow-up, and lack of reporting
of outcomes.
Of the four controlled reports evaluating medial branch
blocks, one study evaluating the therapeutic role was of
moderate quality (481). The remaining three studies were
of low quality for therapeutic purposes (182, 379, 380).
In analyzing the type and strength of evidence due to the
availability of only a total of four controlled studies for
consideration, the evidence from two observational studies
was also utilized. The analysis of type and strength of
efficacy evidence shows that medial branch blocks provide
level III (moderate) evidence. Level III - moderate
evidence is defined as evidence obtained from well-designed
trials without randomization, single group pre- post,
cohort, time series, or matched case controlled studies.
Medial Branch Neurotomy
Multiple investigators have studied the effectiveness of
radiofrequency denervation of medial branches in the spine.
Percutaneous radiofrequency neurotomy is a procedure that
offers temporary relief of pain by denaturing the nerves
that innervate the painful joint (482), but the pain returns
when the axons regenerate. Fortunately, relief can be reinstated
by repeating the procedure. Radiofrequency neurolysis
as a treatment of chronic intractable pain began in
the early 1930s. Shealy (483, 484) pioneered spinal facet
rhizotomy in the 1970s, and Sluijter and Koetsveld-Baart
(319) initiated minimally invasive radiofrequency lesioning
for pain of spinal origin.
Numerous reports describe the technique and effectiveness
of radiofrequency thermoneurolysis (319, 377, 482-511).
Neurolytic blocks (512) and cryogenic neurolysis (513)
also have been described. Success with radiofrequency
neurotomy has been reported in the range of 17% to 90%
for management of lumbar facet joint pain. There were
four prospective randomized studies by Lord et al (487),
Van Kleef et al (488) Dreyfuss et al (510), and Gallagher
et al (510).
Lord et al (482) conducted a prospective, double blinded,
placebo-controlled study of percutaneous radiofrequency
neurotomy for management of chronic cervical facet joint
pain. Lord et al (482) compared percutaneous
radiofrequency neurotomy, in which multiple lesions were
made and the temperature of the electrode was raised to
80°C, with a control treatment using a procedure that was
identical except for the facet that the radiofrequency current
was not turned on. This study included 24 patients (9
men and 15 women) with a mean age of 43 years who
presented with pain in one or more cervical facet joints
after motor vehicle injury. The mean duration of pain was
34 months. Facet joint pain was diagnosed with the use of
double-blinded, placebo-controlled local anesthetic blocks.
The results showed that the median time that elapsed before
the pain returned to at least 50% of the preoperative
level was 263 days in the active treatment group and 8
days in the control group. At 27 weeks, seven patients in
the active treatment group and one patient in the control
group were free of pain. The authors concluded that, in
patients with chronic cervical facet joint pain confirmed
by double-blinded, placebo-controlled local anesthesia,
percutaneous radiofrequency neurotomy with multiple lesions
of target nerves could provide lasting relief.
Van Kleef et al (487), in a randomized trial of radiofre-
Pain Physician Vol. 4, No. 1, 2001