Facet joint pain in chronic spinal pain: an evaluation of prevalence and false-positive rate of diagnostic blocks.

Abstract

A retrospective review.
Evaluation of the prevalence of facet or zygapophysial joint pain in chronic spinal pain of cervical, thoracic, and lumbar origin by using controlled, comparative local anesthetic blocks and evaluation of false-positive rates of single blocks in the diagnosis of chronic spinal pain of facet joint origin.
Facet or zygapophysial joints are clinically important sources of chronic cervical, thoracic, and lumbar spine pain. The previous studies have demonstrated the value and validity of controlled, comparative local anesthetic blocks in the diagnosis of facet joint pain, with a prevalence of 15% to 67% variable in lumbar, thoracic, and cervical regions. False-positive rates of single diagnostic blocks also varied from 17% to 63%.
Five hundred consecutive patients receiving controlled, comparative local anesthetic blocks of medial branches for the diagnosis of facet or zygapophysial joint pain were included. Patients were investigated with diagnostic blocks using 0.5 mL of 1% lidocaine per nerve. Patients with lidocaine-positive results were further studied using 0.5 mL of 0.25% bupivacaine per nerve on a separate occasion. Medial branch blocks were performed with intermittent fluoroscopic visualization, at 2 levels to block a single joint. A positive response was considered as one with at least 80% pain relief from a block of at least 2 hours duration when lidocaine was used, and at least 3 hours or longer than the duration of relief with lidocaine when bupivacaine was used, and also the ability to perform prior painful movements.
A total of 438 patients met inclusion criteria. The prevalence of facet joint pain was 39% in the cervical spine [95% confidence interval (CI), 32%-45%]; 34% (95% CI, 22%-47%) in the thoracic pain; and 27% (95% CI, 22%-33%) in the lumbar spine. The false-positive rate with a single block in the cervical region was 45%, in the thoracic region was 42%, and in the lumbar region 45%.
This retrospective review once again confirmed the significant prevalence of facet joint pain in chronic spinal pain.

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Facet Joint Pain in Chronic Spinal Pain: An Evaluation of
Prevalence and False-positive Rate of Diagnostic Blocks
Rajeev Manchukonda, BDS, Kavita N. Manchikanti, BA, Kimberly A. Cash, RT,
Vidyasagar Pampati, MSc, and Laxmaiah Manchikanti, MD
Study Design: A retrospective review.
Objectives: Evaluation of the prevalence of facet or zygapophy-
sial joint pain in chronic spinal pain of cervical, thoracic, and
lumbar origin by using controlled, comparative local anesthetic
blocks and evaluation of false-positive rates of single blocks in
the diagnosis of chronic spinal pain of facet joint origin.
Summary of Background Data: Facet or zygapophysial joints are
clinically important sources of chronic cervical, thoracic, and
lumbar spine pain. The previous studies have demonstrated the
value and validity of controlled, comparative local anesthetic
blocks in the diagnosis of facet joint pain, with a prevalence of
15% to 67% variable in lumbar, thoracic, and cervical regions.
False-positive rates of single diagnostic blocks also varied from
17% to 63%.
Methods: Five hundred consecutive patients receiving con-
trolled, comparative local anesthetic blocks of medial branches
for the diagnosis of facet or zygapophysial joint pain were
included. Patients were investigated with diagnostic blocks using
0.5mL of 1% lidocaine per nerve. Patients with lidocaine-
positive results were further studied using 0.5mL of 0.25%
bupivacaine per nerve on a separate occasion. Medial branch
blocks were performed with intermittent fluoroscopic visualiza-
tion, at 2 levels to block a single joint. A positive response was
considered as one with at least 80% pain relief from a block of
at least 2 hours duration when lidocaine was used, and at least 3
hours or longer than the duration of relief with lidocaine when
bupivacaine was used, and also the ability to perform prior
painful movements.
Results: A total of 438 patients met inclusion criteria. The
prevalence of facet joint pain was 39% in the cervical spine [95%
confidence interval (CI), 32%-45%]; 34% (95% CI, 22%-47%)
in the thoracic pain; and 27% (95% CI, 22%-33%) in the
lumbar spine. The false-positive rate with a single block in the
cervical region was 45%, in the thoracic region was 42%, and in
the lumbar region 45%.
Conclusions: This retrospective review once again confirmed the
significant prevalence of facet joint pain in chronic spinal pain.
Key Words: facet joints, zygapophysial joints, medial branch
blocks, controlled comparative local anesthetic blocks, cervical
pain, thoracic pain, lumbar pain
(J Spinal Disord Tech 2007;20:539–545)
T
most episodes of low back pain will be short-lived, with
80% to 90% of attacks resolving in about 6 weeks,
irrespective of the administration or type of treatment,
and with only 5% to 10% of patients developing
persistent back pain. However, this belief is flawed as
the condition tends to relapse and most patients will
experience recurrent episodes. Modern evidence has
shown that chronic persistent low back pain and neck
pain are seen in up to 25% to 75% of patients, 1 year or
longer after the initial episode.1,10–18In addition, chronic
pain with the involvement of multiple regions is a
common occurrence in more than 60% of patients.19–22
Yet, even with its high prevalence and scientific advances,
it has been suggested that a specific etiology of back pain
can be diagnosed with certainty in only about 15% of
patients based on clinical examination, radiologic evalua-
tion, and nerve conduction studies in the absence of disc
herniationandradicular
However, on the basis of precision diagnostic blocks,
the diagnosis of the cause of spinal pain may be made in
approximately 85% of the patients.1,24,25
Intervertebral discs, facet joints, ligaments, fascia,
muscles, and nerve root dura have been identified as
tissues capable of transmitting pain in the low back.26
Facet joint pain, discogenic pain, and sacroiliac joint pain
also have been proven to be common causes of pain with
proven diagnostic techniques.1,24,25The facet or zygapo-
physial joints are paired diarthrodial articulations be-
tween posterior elements of adjacent vertebrae. Spinal
facet joints have been shown in normal volunteers to be a
source of pain in the neck and referred pain in the
head and upper extremities,27–30upper back, mid back,
and referred pain in the chest wall,31,32and the low back
and referred pain in the lower extremity.33–37Facet joints
are well innervated by the medial branches of the dorsal
rami.38–40
he lifetime prevalence of spinal pain has been reported
as 54% to 80%.1–9It is conventionally believed that
symptomatology.1,23,24
Copyrightr2007 by Lippincott Williams & Wilkins
Received for publication December 14, 2006; accepted March 1, 2007.
From the Pain Management Center of Paducah, Paducah, KY.
Conflict of Interest: None.
Disclaimer: There was no external funding in preparation of this
manuscript.
Reprints: Laxmaiah Manchikanti, MD, Pain Management Center of
Paducah, 2831 Lone Oak Road, Paducah, KY 42003 (e-mail:
drm@apex.net).
RESEARCH ARTICLE
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Biomechanical studies have shown that lumbar and
cervical facet joint capsules can undergo high strains
during spine-loading.41
Neuroanatomic studies have
demonstrated free and encapsulated nerve endings in
facet joints, and also nerves containing substance P and
calcitoningene-relatedpeptide.41
studies have shown that facet joint capsules contain
low-threshold mechanoreceptors, mechanically sensitive
nociceptors, and silent nociceptors.41
On the basis of controlled diagnostic blocks of facet
joints, in accordance with the criteria established by the
International Association for the Study of Pain,42facet
joints have been implicated as responsible for spinal pain
in 15% to 45% of the patients with chronic low back
pain,21,25,43–4642% to 48% of patients with chronic
thoracic pain,21,47and 54% to 67% of patients with
chronic neck pain.21,48–50
Multiple authors25,43–50in the past have studied
individual regions and presented the results in various
types of practices. Manchikanti et al21evaluated 500
patients in an interventional pain management practice
setting with comparative local anesthetic blocks in a
prospective study and reported the prevalence of facet
joint pain in patients with chronic cervical spine pain as
55%, chronic thoracic spine pain as 42%, and lumbar
spine as 31%. They also reported false-positive rates with
single blocks with lidocaine of 63% in the cervical spine,
55% in the thoracic spine, and 27% in the lumbar spine.
Systematic reviews51,52also have established the preva-
lence, false-positive rates, and the value and validity of
diagnostic facet or zygapophysial joint blocks. Even then,
all these studies were performed by 2 investigators of
heterogenous settings and populations.
Generalizability is a measure of the extent to which
others can achieve the same outcomes as those of original
authors. Consequently, it is an important feature of any
intervention, either therapeutic or diagnostic. In practical
terms, generalizability may be reflected by the extent to
which practitioners in a conventional practice can
reproduce results obtained in academic research studies,
or reproduce the results in a large population base.53
Generalizability is also achieved by multiple prospective
or randomized trials. Consequently, in the case of
prevalence of spinal facet joint pain, all the prospective
studies have been produced by only the 2 groups. Thus,
further trials by different groups are required. However,
another approach is to conduct a retrospective review in a
substantial series of patients. Such an evaluation would
demonstrate whether the same or similar outcomes can be
achieved in practical settings as have been reported in
research studies.
Yet another method of confirming the results of a
previous study and solving the problem of reproducibility
is to conduct a clinical audit on the basis of available data
to ensure this knowledge is being used to the best effect.
Outcomes for a large series of patients, formerly
initiated in 1993 at the United Kingdom’s National
Health Service (NHS), clinical audit was defined as, ‘‘a
quality improvement process that seeks to improve
Neurophysiologic
patient care and outcomes through systematic review of
care against explicit criteria and the implementation
of the change.’’54A recently published clinical audit of
results of radiofrequency neurotomy for chronic neck
pain provided evidence of efficacy and generalizability of
the procedure in routine clinical practice.53
In this study, we sought to evaluate the prevalence
of facet joint pain by spinal region in patients with
chronic spinal pain presenting to an interventional pain
management practice for diagnosis and treatment. We
used the same protocol21as was previously published to
determine the presence of facet joint pain using responses
to controlled comparative local anesthetic facet joint
nerve blocks, performed in accordance with International
Association for the Study of Pain criteria.42
MATERIALS AND METHODS
In this retrospective evaluation, 500 consecutive
patients receiving controlled comparative local anesthetic
blocks were included. The patients presented with chronic
neck, thoracic, or low back pain or a combination
thereof. Patients were managed by one physician in a
nonuniversity, private practice setting in the United
States. The procedures were performed in an interven-
tional pain management ambulatory surgery center. The
practice provides comprehensive, interventional pain
management services.
The chart review was performed by 3 investigators
who were not involved in performing the procedures.
Inclusion criteria at the institution included: con-
secutive patients undergoing controlled comparative local
anesthetic blocks, of ages 18 to 90 years, who had pain for
at least 6 months, which was nonspecific rather than
radicular in nature. The treating physician excluded disc-
related pain with radicular symptoms in all patients based
on radiologic or neurologic testing, lack of a neurologic
deficit, and radicular symptoms or pain that involved
predominantly the upper or lower extremity or chest wall.
All patients selected had failed conservative management
including physical therapy, chiropractic manipulation,
exercises, drug therapy, and bedrest.
Each of the patients had a work-up, which included
comprehensive history, physical examination, and evalua-
tion of the results of prior procedures and investigations.
Of the 500 patients who had undergone controlled
comparative local anesthetic blocks, 438 patients were
eligible to be included in the retrospective review. The
study period lasted from January 2004 to March 2006.
Facet joint pain was investigated in all patients
starting with diagnostic blocks using 1% lidocaine.
Patients with lidocaine-positive results were further
studied using 0.25% bupivacaine on a separate occasion,
usually 3 to 4 weeks after the first injection. The blocks
were performed on the ipsilateral side in patients with
unilateral pain or bilaterally in patients with bilateral or
axial pain. Blocks were performed at a minimum of 2
levels to block a single joint. Target joints were identified
by the pain pattern, local or paramedian tenderness over
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the area of the facet joints, and reproduction of pain with
deep pressure. Blocks were performed with intermittent
fluoroscopic visualization using a 22-gauge, 2-inch spinal
needle at each of the indicated medial branches in the
cervical and thoracic spine, and with a 22-gauge, 3.5-inch
spinal needle at each of the indicated medial branches at
the L1-L4 levels and the L5 dorsal ramus at the L5 level
of the lumbar spine.
Intravenous access was established and light seda-
tion with midazolam was offered to all patients. Each
facet nerve was infiltrated with 0.5mL of 1% lidocaine or
0.25% bupivacaine. Following each block, the patient
was examined and asked to perform previously painful
movements. A positive response was defined as at least an
80% reduction of pain with ability to perform previously
painful movements, as assessed using a verbal numeric
pain rating scale. To be considered positive, pain relief
from a block had to last at least 2 hours when lidocaine
was used, and at least 3 hours, or longer than the duration
of relief with lidocaine, when bupivacaine was used. Any
other response was considered as a negative outcome.
All patients judged to have a positive response with
lidocaine blocks underwent subsequent
blocks. Patients who were determined not to have facet
joint pain were offered other diagnostic or therapeutic
interventions, including discography, epidural injections,
or sacroiliac joint injections.
Data were recorded on a Microsoft Access 97
database. The SPSS version 9.0 Statistical Package was
used to generate frequency tables. The prevalence and
95% confidence intervals (CI) were calculated. Differ-
ences in proportions were tested using the w2test. Fischer
exact test was used whenever the expected value was less
than 5. Results were considered statistically significant if
the P value was <0.05.
bupivacaine
RESULTS
Five hundred consecutive patients undergoing con-
trolled comparative local anesthetic blocks for the
evaluation of facet joint pain were reviewed. Of these,
438 patients met the inclusion criteria. Sixty-two patients
were excluded from the review. Patient flow is illustrated
in Figure 1.
Patient Evaluation Flow Pattern
All the patients were included in the analysis. As
shown in Figure 1, follow-up was not available after the
first block in 4 patients in lumbar, 8 patients in cervical,
and 3 patients in thoracic regions, whereas follow-ups
were not available after the second block in 10 patients in
lumbar, 12 patients in cervical, and 2 patients in thoracic
groups. The results were considered negative or false-
positive for all the patients with lack of follow-up.
Demographic Characteristics
Demographic characteristics are illustrated in Table 1.
Significant differences were identified in patients with
involvement of 1 region and 2 regions with a greater
proportion of female patients compared with male. An
additional variable in the demographic characteristics was
height, which was greater in patients with involvement of
1 region compared with 2 regions or 2 to 3 regions.
Salient features based on regional involvement of
the spine are illustrated in Table 2. There were no
significant differences noted in any of the variables.
Results of Comparative Local Anesthetic Blocks
Table 3 illustrates the results of diagnostic blocks
evaluating facet joint pain in all 3 regions. In the cervical
spine, lidocaine blocks were performed in 251 patients, in
65 patients in the thoracic spine, and 303 patients in the
lumbar spine. Of these, 175 of 251 patients in the cervical
spine reported a definite response with a positive result to
initial lidocaine blocks, whereas 38 of the 65 patients in
the thoracic spine reported a positive result, and 150 of
303 patients with lumbar spinal pain reported positive
results with a single lidocaine block.
Of the 175 patients positive for single blocks with
lidocaine, 97 patients reported positive response to
bupivacaine blocks in the cervical spine, whereas 22 of
38 patients in the thoracic spine positive for single
lidocaine blocks were also positive with bupivacaine
blocks. Eighty-three patients in the lumbar spine showed
positive results with bupivacaine from 150 of the
lidocaine positive patients.
The controlled comparative local anesthetic blocks
with positive results using double local anesthetic blocks
provided a prevalence rate of facet joint pain in patients
with chronic neck pain of 39% (95% CI, 32%-45%); 34%
(95% CI, 22%-47%) in patients with chronic thoracic
pain; and 27% (95% CI, 22%-33%) in patients with
chronic low back pain.
Table 3 also illustrates false-positive rates. False-
positive rates were calculated by assuming all patients
with no response to lidocaine to be true negative, and all
patients with a positive response to lidocaine and a
negative response to bupivacaine or positive response to
both lidocaine and bupivacaine as false-positives. The
false-positive rates for cervical facet joints with a single
block were 45% (95% CI, 37%-52%), for thoracic facet
joints with a single lidocaine block were 42% (95% CI,
26%-59%), and for lumbar spine 45% (95% CI,
36%-53%).
Characteristics of Regional Involvement
Table 4 illustrates facet joint involvement by region
on the basis of controlled comparative local anesthetic
blocks. Overall, at least one region was judged to be
positive in 156 patients or 36% of the 438 patients.
However, in 25% of the 181 patients were positive among
patients with involvement of 2 and 3 regions.
Adverse Effects
No major adverse effects were noted in this study.
DISCUSSION
This retrospective evaluation of patients with
chronic nonspecific spinal pain involving the cervical,
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thoracic, and lumbar regions, alone or in combination,
demonstrated by spinal region that the prevalence of
cervical facet or zygapophysial joint pain in patients with
neck pain is 39%, thoracic facet joint pain in patients
with mid back or upper back pain is 34%, and
involvement of lumbar facet joints in patients with
chronic low back pain is 27%. The prevalence will be
reduced if it is calculated on the basis of the total number
of patients evaluated for the entire spine rather than
regional. Thus, these numbers show regional involvement
and evaluation of the patients for that particular region.
These results are in overall agreement with the previous
studies, although somewhat less than the ones published
by the same group.21
The false-positive rates were quite high with single
blocks: 45% for the cervical spine, 42% for the thoracic
spine, and 45% for the lumbar spine. Once again, the
results are similar to previous findings, even though there
are some differences with the same group of authors with
the results published in a prospective evaluation.21,25,43–52
Eligible PatientsAssessed
500
Patients included
for evaluation= 438
Involvement of
one region = 272
Involvement of
two regions = 151
Involvement of
three regions = 15
Lumbar pain = 303
Cervical pain = 251
Thoracic pain = 65
Patients included in
analysis = 303
Patients included in
analysis = 251
Patients included in
analysis = 65
Follow-up not available
after 1 block = 4
Follow-up not available
after 2
block = 10
Total = 14
Follow-up not available
after 1 block = 8
Follow-up not available
after 2
block = 12
Total = 20
Follow-up not available
after 1 block = 3
Follow-up not available
after 2
block = 2
Total = 5
Patients not meeting inclusion criteria = 62
36 patients did not meet at least 6 months
duration of pain criteria
4 patients were less than 18 years of age
12 patients have undergone surgical
intervention within the past 6 months in
cervical, thoracic, or lumbar spine with disc
procedures or vertebroplasty
10 patients had no information with
evaluation for disc-related problems or had
no information on conservative treatment
prior to facet joint blocks
Results were considered
negative = 4
Results were considered
false-positive = 14
Results were considered
negative = 8
Results were considered
false-positive = 20
Results wereconsidered
negative = 3
Results were considered
false-positive = 5
FIGURE 1. Schematic representation of
the review and patient flow.
TABLE 1. Demographic Characteristics
One Region
(272)
Two Regions
(151)
Three Regions
(15)
Total
(438)
Sex
Male45% (122)26% (39) 33% (5)38%
(166)
62%
(272)
Female55%*(150)74%*(112)67% (10)
Age (y)
Range
Mean±SEM
Weight (lbs)
Range
Mean±SEM
Height (in)
Range
Mean±SEM 67.3w±0.2
18-92
48±1.0
17-84
46±1.2
25-57
42±2.4
17-92
47±0.7
97-390
187±2.9
99-427
180±4.1
123-220
173±7.2
97-427
184±2.3
57-7658-76
65.9±0.3
60-72
65.1±1.0
57-76
66.8±0.2
*Significant difference compared to the male with involvement of 1 or 2
regions (P<0.01).
wSignificant difference compared to the group with involvement of 2 or 3
regions (P<0.05).
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The study also demonstrated bilateral involvement
in 72% of patients in the cervical spine, 80% in the
thoracic spine, and 79% in the lumbar spine. Overall 77%
of the patients presented with bilateral involvement. In
addition, this study also showed involvement of multiple
regions with 38% of the patients with involvement of
more than one region.
This study once again reaffirms the evidence that
involvement of facet joints, as a cause of chronic spinal
pain is real as proven overwhelmingly by numerous
studies. Facet joints have been shown to be a source
of chronic spinal pain by means of diagnostic techniques
of known reliability and validity.21,25,43–52,55–59Blocks of
facet joints are performed to test the hypothesis that the
target joint is a source of the patient’s pain.55Once a facet
joint is anesthetized by the medial branches of the
dorsal rami that innervate the target joint, if pain is
relieved, the joint is considered to be the source of pain.55
However, true-positive responses are determined by
performing controlled blocks, either in the form of
placebo injection of normal saline or more commonly in
the form of comparative local anesthetic blocks on
2 separate occasions, when the same joint is anesthetized
using local anesthetics with different durations of action.
The value and validity of medial branch blocks and
comparative local anesthetic blocks in the diagnosis
of facet joint pain has been demonstrated.21,25,43–52,55–67
In addition, because there are no clinical features or
diagnostic imaging studies that can determine whether
a facet joint is painful or not, controlled blocks seem
to be a reliable tool in the diagnosis of chronic spinal
pain.
The results noted in this study confirm the previous
results, lending external validity to the primary findings.
The study was performed in the setting of an interven-
tional specialty practice in a private practice setting in the
United States. Yet, it may be criticized that the authors
performing the procedures in the retrospective review also
was involved in the primary study. On the one hand, this
may provide uniformity. On the other hand, it provides
basis for the criticism that the results are the same. This
criticism may be invalidated by the fact that the present
retrospective study shows lesser prevalence of facet
joint pain. Prevalence of facet joint pain was 55% in
the cervical spine, 42% in the thoracic spine, and 31%
in the lumbar spine compared with 39% in the present
study in the cervical region, 34% in the thoracic
region, and 27% in the lumbar region. This study also
reinforces that the results of a retrospective review can
provide valuable information similar to a prospective
evaluation.
Even though the existence of facet joint pain is not
universally accepted and the diagnostic methodology is
not endorsed, it is the best available method to diagnose
facet joint pain in chronic spinal pain. By confirming the
results of the original research studies of diagnostic facet
joint blocks, the results of the present study might
encourage others to use appropriate diagnostic techniques
in managing chronic spinal pain.
TABLE 2. Baseline Salient Features Based on Regional
Involvement of the Spine
Cervical (251)Thoracic (65) Lumbar (303)
Sex
Male
Female
Age (y)
Range
Mean±SEM
Height (in)
Range
Mean±SEM
Weight (lbs)
Range
Mean±SEM
Duration of Pain (mo)
Range
Mean±SEM
Mode of onset of pain
Gradual
Following an incident
Distribution of pain
Left
Right
Bilateral
No. joints involved
2
3
Z4
31% (79)
69% (172)
29% (19)
71% (46)
39% (117)
61% (186)
17-78
45.4±0.9
20-92
45.4±2.1
17-89
47.7±0.9
58-76
66.4±0.2
59-76
66.1-0.5
57-76
66.7±0.2
99-427
180.3±2.9
113-287
168.3±4.2
97-427
187.4±3.0
6-338
85.6±5.3
6-330
75.8±9.6
6-430
107.5±6.2
55% (138)
45% (9113)
60% (39)
40% (26)
54% (164)
46% (139)
15% (38)
13% (33)
72% (180)
5% (3)
15% (10)
80% (52)
9% (26)
12% (38)
79% (239)
50% (127)
49% (122)
1% (2)
19% (12)
29% (19)
52% (34)
63% (191)
36% (109)
1% (3)
TABLE 3. Results of Single and Double Facet Joint Nerve Blocks (Single Blocks With Lidocaine and Double Blocks With Lidocaine
and Bupivacaine)
Cervical (251)
Double Blocks*
Thoracic (65)
Double Blocks*
Lumbar (303)
Double Blocks*
Single Blocksw
Positive NegativePositive Negative PositiveNegative
Positive
Negative
Prevalence
False-positive rate
97
—
39% (95% CI, 32%-45%)
45% (95% CI, 37%-52%)
78
76
22
—
34% (95% CI, 22%-47%)
42% (95% CI, 26%-59%)
16
27
83
—
27% (95% CI, 22%-33%)
45% (95% CI, 36%-53%)
67
153
*With double blocks, 97 patients with neck pain, 22 with thoracic pain, and 83 with lumbar pain had positive responses.
wWith single blocks in the cervical spine, 175 patients (ie, 97+78) had positive responses with lidocaine blocks, 38 (22+16) patients with thoracic pain had positive
responses, and 150 (83+67) patients with lumbar pain had positive responses.
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