Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6012_Библиотеки_им_академика_М_И_Перельмана.pdf
Chapter 16 Targeting Pain Generators 273
diagnosis of zygapophyseal joint pain was made in 40% (95%
CI, 27–53%). Requiring 90% relief of original pain, the prevalence was 32%; requiring 100% relief, the prevalence was 11%.
Manchikanti and colleagues
105
reported an even higher prevalence of 52% zygapophyseal joint pain in a group of patients
65 years old or older.
No consistent history, physical examination, or imaging
ndings correlated to positive block responses have been
found. In the early 1980s, uncontrolled single, variable injectant volume, intraarticular zygapophyseal joint injections
were used as the reference standard for identifying lumbar
zygapophyseal joint pain; these authors reported correlations
with various history or physical examination ndings.
Some studies
108,109
reported that a cluster of ve of seven fea-
52,107
tures (Revel criteria) could predict a 75% decrease in pain aer
a single intraarticular block. e seven items in the cluster are
age older than 65 years, pain well relieved by recumbency, no
exacerbation of pain with coughing and sneezing, no exacerbation of pain with forward exion, no exacerbation of pain
with extension, no exacerbation of pain with rising from
exion, and no exacerbation of pain with the extensionrotation test. Subsequent well-conducted studies did not replicate these studies.
32,110
As mentioned, most of these earlier
studies used single medial branch blocks, which have been
reported to have 25% and 38% false-positive rates for the
diagnosis of zygapophyseal joint pain.
111,112
Newer studies of clinical correlations rened the technique
with an appropriate injectant volume and a conrmatory
double-block paradigm with either a second intraarticular
injection or a medial branch conrmatory injection with
bupivacaine lasting longer than the pain relief aer a prior
lidocaine block
30,96,106,111,113–115
ese studies did not nd any
clinical correlates with history or physical examination. In
particular, extension and rotation were not predictive of
response. A systematic review of all published studies comparing clinical outcome aer local anesthetic blocks and clinical
signs and symptoms found no consistent clinical features with
a high specicity.12 e review found several clinical features
with a high sensitivity, however, which may be cautiously used
to exclude the diagnosis of zygapophyseal joint–mediated
pain. ese features include pain not increased with cough,
pain not relieved with recumbency, and pain that can be
centralized.50 ere are no consistent reproducible history or
physical examination criteria that predict a positive response
to a zygapophyseal joint block. History and physical examination are better at ruling out zygapophyseal joint–mediated
pain than diagnosing zygapophyseal joint pain.
e current best evidence also shows that radiologic
imaging, with a few more recent exceptions, does not correlate
with response to zygapophyseal joint blocks. Conicting evi-
dence that radiologic imaging may predict outcome from
uncontrolled lumbar zygapophyseal joint blocks may be partially due to lack of rigor in the reference standard used to
dene a positive response in earlier studies.22 In 1979,
Carrera
115
reported that 73% (n = 63) of patients describing
pain relief aer uncontrolled intraarticular injection of 2 to
4 mL of local anesthetic had CT evidence of lumbar zygapophyseal joint disease versus 13% who had no evidence of
disease. It is well accepted, however, that injectant volume
should not exceed 1 mL; otherwise, the injection loses speci-
city, with a leak/extravasation of local anesthetic and potential
contact with the adjacent spinal nerve root or other possible
pain generators located outside of the zygapophyseal joint, as
described earlier.
A large study by Jackson and colleague
96
116
of 390 patients
found no relationship between imaging and pain relief aer
uncontrolled intraarticular lumbar zygapophyseal joint injections. Supporting the ndings by Jackson and colleagues,
Schwarzer and colleagues,
106
in the only study using placebocontrolled injection, found no correlation between CT ndings and a positive response comparing local anesthetic with
saline blocks in 63 patients when more stringent criteria of
controlled injections were used as the reference standard.
Similarly, Cohen and colleagues
117
found no relationship in
192 patients between MRI ndings of zygapophyseal joint
hypertrophy or degeneration and response to medial branch
neurotomies based on positive response to a single medial
branch block. Kawaguchi and colleagues
118
likewise found no
signicant relationship between low back pain symptoms and
radiographic abnormalities in a group of 106 patients with
rheumatoid arthritis.
e intriguing bright spot on the horizon is the nding
that where MRI or single photon emission computed tomography (SPECT) shows imaging ndings consistent with either
“inammation” or “edema,” a stronger correlation emerges
(Fig. 16.5). Although not conrming the diagnosis of zyg-
apophyseal joint pain with a reference standard, Friedrich and
colleagues
119
more recently found that an estimated 14% (21
of 145) of patients with low back pain had MRI evidence
of zygapophyseal joint edema, and follow-up MRI scan
showed “almost perfect” agreement between change in pain
and a reduction in intensity of edema on sagittal short-tau
FIG. 16.5 L5–S1 axial T2-weighted magnetic resonance image showing
zygapophyseal edema (right greater than left), suggestive of instability. In
the upright weight-bearing position, anterolisthesis was noted; in the
unloaded supine position, anterolisthesis reduced and zygapophyseal joints
are gapped and lled with uid. (Courtesy Richard Derby, MD.)
116
SECTION
II
274 DIAGNOSIS
Normal Abnormal
inversion recovery images. Radionuclide bone scintigraphy
detects bone areas with synovial changes (inammation or
hyperemia) or increased osteoblast activity and degenerative
regions with a high degree of remodeling. Osteophytes in the
process of growing show a high degree of bone scan activity.
As mentioned earlier, a positive lumbar SPECT scan predicts
a statistically signicant reduction in pain aer zygapophyseal
joint blocks.
33
Zygapophyseal Joint Pain Referral Maps
Pain referral patterns have been studied using stimulation of
patients during provocative diagnostic injections
tion of hypertonic solutions into normal and abnormal sub-
121
jects
or by electrical stimulation of medial branches.
Most studies showed distinct but overlapping referral areas; it
is likely that the pain referral patterns obtained in normal
volunteers are smaller because of less sensitization. ere are
also limits to the referral maps; Mooney and Robertson
reported on lumbar zygapophyseal joint referral maps in
normal volunteers and subjects with a positive diagnostic
zygapophyseal joint block (Fig. 16.6). Under uoroscopic
guidance, they injected contrast dye (unspecied volume)
followed by 3 to 5 mL of hypertonic saline. Some of the distal
extremity pain seen in the diagrams may be due to excessive
volume of saline with irritation of the sciatic nerve roots.
Given the lack of sensitivity and specicity of history, physical
examination, and imaging and until more research is performed with nite injectant volumes (in patients with conrmed dual positive blocks), these referral maps can be used
as a starting point to guide selection of levels to be injected.
FIG. 16.6 Pain referral patterns for asymptomatic (normal) and
symptomatic (abnormal) subjects obtained by intraarticular zygapophyseal
joint injection of contrast dye followed by 3 to 5 mL of hypertonic saline.
(From Mooney V, Robertson J. The facet syndrome. Clin Orthop Relat Res.
1976;115:149–156.)
120
by injec-
120,121
121
Predictive Value
How useful are diagnostic zygapophyseal joint injections? e
predictive value of any spinal diagnostic test directly varies
with the rigorousness of test standards and the inherent ability
of that treatment to alleviate the source of pain without creating new sources unrelated to the original cause or causes. A
positive test is valuable if it can guide treatment and obtain
better outcomes than not using the diagnostic test at all. A
systematic review of the evidence for treatment of zygapophyseal joint pain is beyond the scope of this chapter; however, a
case is made for the therapeutic utility of zygapophyseal joint
blocks.
Historically, lacking robust studies, guideline and systematic review articles have been relegated to quoting studies
with methodologic aws as implied evidence that one need
not diagnose zygapophyseal joint–mediated pain before
surgery.
relief aer uncontrolled, variable volume, intraarticular
zygapophyseal joint blocks should predict fusion outcomes
using surgical fusion techniques from the 1980s in a group of
patients being operated on for various unknown or unstated
reasons. Jackson
patients from 1980 to 1988 to results of a single intraarticular
zygapophyseal joint injection with 1.5 mL of local anesthetic
and an unknown volume of contrast dye. Of the patients,
85% had “some improvement” with an average relief aer
injection of 29%. e authors found no relationship between
fusion surgery performed for unstated reasons and a “favorable response” to zygapophyseal joint injection. e surgeries
were presumably performed not because the authors believed
the patients’ symptoms were due to their zygapophyseal joints.
e surgical results based on their “mean pain and functional
assessment scores” also seemed to improve by signicantly less
than 50%, suggesting poor patient selection.
Moro in 1993,
utility of zygapophyseal joint blocks; however, it warrants
a careful, critical review. ese authors concluded that
single intraarticular diagnostic zygapophyseal joint injections
“should not be used in determining treatment because they are
not predictive of either surgical or nonsurgical success.” is
study had signicant methodologic shortcomings, which limit
the validity of the authors’ conclusions. First, the study was
retrospective, with patients surveyed by telephone approximately 5 years aer surgery. Second, 1.5 mL of local anesthetic
was injected into the zygapophyseal joints, and no mention
is made of the volume of contrast dye needed to conrm
needle position; the injections likely were nonspecic because
of zygapophyseal joint capsule rupture from excessive volume
(>1.5 mL). ird, the patient population was markedly heterogeneous, with signicant confounding factors: an average
duration of back pain of 8 years and approximately 40% of
patients with a history of prior surgeries, including failed
fusions. More than 50% of patients underwent three-level,
four-level, or ve-level fusions, which are known to have a
worse outcome than single-level or two-level fusions. Fourth,
of the 82 patients who underwent surgery, 36 (44%) had 0%
24,98
ere is no reason that a variable amount of
122
correlated relief aer spinal fusion in 36
An important historical study, published by Esses and
123
is oen quoted to refute the therapeutic
Chapter 16 Targeting Pain Generators 275
relief from zygapophyseal joint injections. Almost half of the
patients undergoing surgery had no relief from diagnostic
blocks. Eight of 19 (42%) of the patients with complete relief
aer zygapophyseal joint injections declined surgery, leaving
only 11 of 82 (13%) patients who underwent surgery who had
100% relief from zygapophyseal joint blocks. e remaining
35 of 82 patients (43%) had “partial but signicant relief”
(the exact percentage relief is not reported). Fih, 30 of 82
(37%) patients had prior surgeries (laminectomy, discectomy,
and fusion). It is well known that patients with failed back
surgery syndrome oen fare poorly with repeat surgery. Also,
during the 1980s, diagnosis of the etiology of failed back
surgery syndrome was elusive and might not be corrected
by a posterior arthrodesis. For failed back surgery syndrome,
zygapophyseal joint pain comprises only 3% of cases; the
most common diagnoses are foraminal stenosis (25–29%),
painful disc (20–22%), pseudarthrosis (14%), neuropathic
pain (10%), recurrent disc herniation (7–12%), and sacroiliac
joint pain (2%).
Next, Esses and Moro
124
123
did not match the surgery to
specic zygapophyseal joint levels blocked. Patients had either
one-level or two-level zygapophyseal joint blocks, yet the following posterior fusions were performed: 20 single-level;
three two-level; 10 three-level; four four-level; and 12 ve-level
or greater, including thoracic spine (wherein zygapophyseal
joints were never blocked). Finally, signicant questions arise
regarding the ecacy of the surgical intervention because
there was no signicant dierence between surgical and
nonsurgical outcomes. As reported, only approximately onethird of patients in either the surgical or the nonsurgical group
had a good outcome. Because of methodologic aws and limi-
tations of the Esses and Moro study,
123
zygapophyseal joint
intraarticular injections cannot be impugned as either predictive or nonpredictive of surgical success.
In another observational study, Lovely and Rastogi
125
required a “positive response” to intraarticular injection of
greater than 70% relief aer bupivacaine zygapophyseal joint
block for 6 hours and required a conrmatory response on
two subsequent injections. Of 28 patients, 23 had a good to
excellent outcome aer fusion surgery; however, large volumes
of 3 to 5 mL were used during the blocks, making interpretation dicult. At present, there is no research regarding the
utility of cervical or thoracic zygapophyseal joint blocks as
presurgical screening tests.
By comparison, when a specic treatment is directed at a
cause of pain originating from the zygapophyseal joint, accurate diagnostic testing does matter. In a more recent study,
researchers reported that when a putative inammatory cause
of lumbar zygapophyseal joint pain was conrmed using a
positive SPECT scan, a positive response (a signicant reduction in pain) was clearly predicted with intraarticular and
pericapsular steroids at 1 and 3 months compared with subjects
with negative scans or routine care.
33
In contrast to diagnostic intraarticular zygapophyseal joint
injections, evidence supports the use of diagnostic medial
branch nerve blocks (MBBs) as the criterion standard to
diagnose zygapophyseal mediated pain.
17,126
Using controlled
blocks and progressively stringent pain relief requirements
for a positive block incrementally decreases the potential
false-positive rate and improves results for a well-validated
treatment for zygapophyseal joint pain, medial branch
neurotomy.
17,126–128
Most consensus standards for diagnosis of zygapophysealmediated pain require at a minimum 70% to 80% reported pain
relief for the duration of the local anesthetic obtained in two
separate sessions.
17,126
In particular, Dreyfuss and colleagues,
studied patients who obtained greater than or equal to 80%
relief from MBBs selected to undergo lumbar radiofrequency
neurotomy. At 12 months, 60% of the patients obtained at least
90% relief of pain, and 87% obtained at least 60% relief. Dreyfuss and colleagues
129
concluded that lumbar medial branch
neurotomy is an eective means of reducing pain in patients
carefully selected on the basis of controlled diagnostic blocks.
A high-quality study randomized controlled trial evaluating
radiofrequency neurotomy in patients with chronic low back
130
pain
used three positive blocks in the inclusion criteria
and a “sham radiofrequency” procedure for comparison;
statistically signicant reduction in pain and improvement
in various quality-of-life variables were obtained. In another
study, when the diagnosis is conrmed by relief of pain for
greater than 3 months aer medial branch neurotomies,
repeat neurotomies are successful in greater than 75% in the
lumbar and cervical spine.
131,132
More recently, Derby et al.
used percent pain relief following MBB in 10% increments,
nding a statistically favorable outcome for medial branch
neurotomy using an MBB protocol requiring 70% or greater
reported pain relief for the duration of the local anesthetic
recorded on two separate sessions (double-block protocol).
Using a single-session protocol, 80% or greater report of pain
relief predicted favorable medial branch neurotomy outcome,
albeit less favorable than the two-session protocol.
127,133
In regard to newer surgical treatments, the development
and perfection of procedures such as minimally invasive
zygapophyseal joint fusions or various types of total and
subtotal arthroplasties require accurate diagnosis along with
stringent criteria for success. e many confounding variables
and oen-reported weak results of current spinal fusion and
arthroplasty techniques make disproving these results relatively easy. e diagnosis of zygapophyseal joint pain employ-
ing strict double-block or placebo-controlled standards should
perhaps be used to restrain a surgeon from oering a circum-
ferential (360 or 280 degrees) segmental fusion or arthroplasty.
e failure to conrm zygapophyseal joint pain is perhaps
even more important because doing so leaves other sources of
pain that may be better suited to a particular surgical technique or limits the number of levels needing stabilization.
Cervical Spine Zygapophyseal Joint Syndrome
History
e cervical zygapophyseal joints are known to be sources
of persistent chronic pain and central sensitization.
1940, Hadden
causing headache. In the 1970s, Macnab
arising from the zygapophyseal joints aer whiplash injury.
Bogduk and Marsland
136
described pain from zygapophyseal joints
138
devised a technique to block the
137
described pain
134,135
129
127
In
SECTION
II
276 DIAGNOSIS
AB
Third occipital
third occipital nerve, which relieved neck pain and headache
stemming from the C2–C3 zygapophyseal joint in 70% of
patients. Headache arising from C0–C1 or C1–C2 joints has
also been described.
139,140
Bogduk and Marsland
141
were also
the rst to describe medial branch blocks for all cervical spine
levels. ey studied patients presenting with idiopathic neck
pain and reported that medial branch block and intraarticular
blocks provided complete, temporary relief of pain for 70%
of patients.
Cervical Zygapophyseal Joint Pain
Based on the conrmatory block paradigm, the cervical zygapophyseal joints are a common source of chronic neck pain;
the prevalence of cervical zygapophyseal joint syndrome is
greater than the prevalence of lumbar zygapophyseal joint
syndrome. Cervical discogenic pain shares referral patterns
with zygapophyseal joint pain, but it is far less common.
Based on comparative blocks of cervical zygapophyseal joints
causing chronic neck pain with either associated headache or
shoulder pain, the C2–C3 (36%) and C5–C6 zygapophyseal
joints (35%) were the most common pain generators.
whiplash injury, level I prospective clinical studies provide
evidence that zygapophyseal joints are the most common
source of chronic pain.
144,145
Cervicogenic headache stemming
from the C2–C3 zygapophyseal joint aer whiplash has a 53%
prevalence.
144
Oen neglected are C0–C1 and C1–C2 joints in evaluation
of upper neck pain and headache. Dreyfuss and colleagues
studied the referral patterns for the atlantoaxial and lateral
atlantoaxial joints. In 2002, Aprill and colleagues
146
conrm the null hypothesis that lateral atlantoaxial joints are
not a common source of occipital headache. ese investigators found that of 34 patients presenting with symptoms and
signs of atlantoaxial joint pain, 21 obtained complete relief of
headache aer diagnostic injection of local anesthetic. Pain
referral patterns have been dened in C2–C3 through C7–T1
zygapophyseal joints (Fig. 16.7).
zygapophyseal joints is well described (Fig. 16.8).
147
Innervation of the cervical
147
e cervical zygapophyseal joints can be blocked either by MBBs or
with intraarticular injections (Fig. 16.9).
Prevalence rates for neck pain originating from cervical
zygapophyseal joints range from 36% to 60%. e false-positive
rate for a single, uncontrolled block is 27% (95% CI, 15–38%).
e following prevalence rates (mean [95% CI]) are reported
from studies using either a double-block or a triple-block
paradigm (normal saline as a placebo): 54% (95% CI,
40–68%),
33–64%),
colleagues
144
36% (95% CI, 27–45%),
145
and 60% (95% CI, 50–70%).
151
restudied the prevalence of cervical zygapophy-
149
60% (95% CI,
150
Manchikanti and
seal joint pain in a larger group of patients and found a similar
55% (95% CI, 49–61%) prevalence. In a study by Manchikanti’s
group in 2007,85 of 438 patients requiring 80% relief of pain
for 2-hour duration with lidocaine and 3-hour duration with
bupivacaine, a 39% prevalence of zygapophyseal joint–
mediated pain was demonstrated. Corroborating the high
prevalence of cervical zygapophyseal joint pain, Yin and
Bogduk
186
in a private practice clinic audit found a 55%
142
143
Aer
139
failed to
148
C2-3
C3-4
C4-5
C6-7
C5-6
FIG. 16.7 Patterns of referred pain from cervical zygapophyseal joints in
normal volunteers (From Dwyer A, Aprill C, Bogduk N. Cervical
zygapophyseal joint pain patterns. Part 1: a study in normal volunteers.
Spine. 1990;15:453–457.)
nerve
C2
C3
C4
C5
C6
C7
FIG. 16.8 (A) Lateral view of cervical spine showing variable locations of
medial branches. At C3, the location of the C3 deep medial branch is
shown. The inset shows the location of the third occipital nerve. The shaded
area shows where the C3 deep branches and third occipital nerve overlap.
The C5 medial branch is located in the middle of the articular pillar; at C6
and C7, medial branches are located progressively higher. (B)
Anteroposterior view of the cervical medial branches. (From Bogduk N, ed.
Practice Guidelines for Spinal Diagnostic and Treatment Procedures. San
Francisco: International Spine Intervention Society; 2004.)
C2
C3
prevalence of cervical zygapophyseal joint–mediated neck
pain using a strict double-block comparative protocol. In a
recent well-executed prospective outcome study, MacVicar
152
et al.
further corroborated the diagnostic value of diagnostic
MBBs. His study found that 100% pain relief following rigorously evaluated comparative MBBs predicted that between
61% to 74% of patients will obtain 80% or greater pain relief
following cervical medial branch neurotomies for an average
of 17 to 20 months aer the primary procedure and an average
of 15 months aer repeat procedures.
152
Similar to lumbar zygapophyseal joint pain, there are no
T4–5
T6–7
T8–9
T10–1
2
high-quality studies showing a particular set of clinical features that can predict results of diagnostic cervical zygapophyseal joint blocks or MBBs.
153
With diagnosis by MBBs, one
exceptionally skilled manipulative therapist was able to identify
all 15 subjects with diagnostic block–proven symptomatic
zygapophyseal joints and specify the correct symptomatic
segment. None of the ve patients with asymptomatic joints
was misdiagnosed as having symptomatic zygapophyseal
C3
C3\4
R
FIG. 16.9 Lateral uoroscopic view of a C3–C4 zygapophyseal joint
injection using a 3.5-inch, 25-gauge needle. Note contrast dye in posterior
and anterior capsular folds (arrows). (Courtesy Richard Derby, MD.)
C4
C5
Chapter 16 Targeting Pain Generators 277
154
joints.
A later follow-up study by the same group failed to
conrm the apparent high specicity and sensitivity, however,
and reported a high sensitivity but low specicity and concluded that manual examination of the cervical spine lacks
validity for the diagnosis of cervical zygapophyseal joint pain.
In the study by Aprill and colleagues
146
of C1–C2 zygapophyseal joint pain as a source of occipital headache, only 60% of
the patients shared clinical criteria that predicted a positive
response to the block.
Advanced imaging has not been correlated with positive
responses to diagnostic blocks. Hechelhammer and col-
155
leagues
found no relationship between short-term pain
relief aer cervical intraarticular and pericapsular injection of
local anesthetic and corticosteroid and the degree of osteoarthritis graded on a CT scan.
Thoracic Spine
e prevalence of patients who complain of chronic upper
back or mid-back pain ranges from 3% to 22%.
survey study of 35- to 45-year-old patients estimated the
prevalence of thoracic pain to be 15%.
158
oracic zygapophy-
seal joint pain referral patterns have been reported (Fig.
159,160
16.10).
described (Fig. 16.11).
oracic medial branch anatomy has also been
161
However, it must be acknowledged
that a “thoracic zygapophyseal joint syndrome” has not been
described in detail relative to the cervical and lumbar zygapophyseal joint syndromes outlined earlier. Given the relative
lack of mobility in the sagittal plane (i.e., exion and exten-
sion) at the thoracic zygapophyseal joints due to their relatively
coronal orientation, less loading stress occurs at these levels
32,156,157
One
SECTION
II
T1–2
T1
T3–4
T7
1
L5
A
FIG. 16.10 Maps of referred pain patterns in segments indicated. (A) Based on Dreyfuss et al.
volunteers. (B) Based on Fukui et al.
N, ed. Practice Guidelines for Spinal Diagnostic and Treatment Procedures. San Francisco: International Spine
Intervention Society; 2004.)
160
in patients with single positive zygapophyseal joint block. (From Bogduk
T5–6
T7–8
T9–10
B
T1
T7
L5
139
in normal
T11–1
278 DIAGNOSIS
A
B
T7
T1
T2
T3
T4
T5
T6
T7
FIG. 16.11 (A–B) Composite sketch of work by Chua and Bogduk
radiographs of cadaveric thoracic spines. Medial branches of thoracic dorsal
rami marked with wires to depict location with respect to transverse
processes. Note middle thoracic levels, where medial branches are within
intertransverse space versus crossing transverse process. (From Bogduk N,
ed. Practice Guidelines for Spinal Diagnostic and Treatment Procedures. San
Francisco: International Spine Intervention Society; 2004.)
T8
T9
T10
T11
T12
L1
161
with
relative to the cervical and lumbar zygapophyseal joints during
extension movements and postures.
162,163
ere are no pathognomonic clinical or radiographic ndings by which thoracic zygapophyseal joint pain may be
diagnosed.
164
As with the cervical and thoracic spine, diagnosis
is by suspicion and, at a minimum, the pain pattern should
correlate with established pain referral maps.
147
e methods
that physicians apply clinically to the diagnosis and treatment
of thoracic zygapophyseal joint pain rest largely on research
done in the lumbar and cervical spine. is is not an entirely
unreasonable approach based on what clinicians know in
general regarding zygapophyseal joint anatomy and innervation; however, more research is needed.
Investigators have mapped out the referral patterns for the
thoracic joints. ese ndings are oen used as a starting
point to select which thoracic zygapophyseal joints to
block.
159,160
Dreyfuss and colleagues
159
mapped out thoracic
zygapophyseal joint referral patterns in normal volunteers and
found that capsular distention did not provoke pain in 27.5%
of volunteers. Fukui and colleagues
160
mapped out referral
patterns in patients with suspected thoracic zygapophyseal
joint pain who had a positive response to local anesthetic in
C7–T1 to T2–T3 and T11–T12 zygapophyseal joints. ere
was considerable overlap between the C7–T1 and T2–T3
thoracic joints; thus, pain maps from these joints are not
considered reliable enough to identify the symptomatic segmental level. Dreyfuss and colleagues
159
studied nine asymp-
tomatic volunteers who underwent 40 provocative thoracic
L
T3/4
FIG. 16.12 Left T3–T4 zygapophyseal joint intraarticular injection. Note
circular zygapophyseal joint arthrogram (arrow). (Courtesy Richard Derby,
MD.)
zygapophyseal joint injections from T3–T4 to T10–T11.
Referral patterns were consistently unilateral. e area of the
most intense pain for segments from T2–T3 to T11–T12 was
one level inferior and lateral. Signicant overlap occurred over
three to ve levels. e researchers found that needle position
can be conrmed with 0.1 to 0.3 mL of contrast dye, and
adequate blocks can be achieved with a volume of 0.5 to
0.6 mL. Normally, thoracic zygapophyseal joints cannot hold
more than 0.75 mL (Fig. 16.12 shows a typical thoracic zygapophyseal joint block).
17
One research group has performed the three studies in the
literature using a controlled, double-block paradigm, requiring 75% to 80% relief based on the duration of the local
anesthetic used.
105,165,166
Combining all three studies with
patients presenting with chronic middle or upper spinal pain
(n = 183), using dual blocks obtains a 40% prevalence of
thoracic zygapophyseal joint syndrome, with a false-positive
rate of 42% if using a single-block paradigm.
28
What is the predictive value of a positive dual block? In other
words, how well do patients fare who have positive dual blocks
and undergo therapeutic intervention? Research is limited in this
regard. One systematic review28 reported that only therapeutic
thoracic MBBs received a 1A or 1B/strong recommendation.
Manchikanti and colleagues
167,168
performed two studies. In the
rst study, 55 consecutive patients were studied; greater than
70% of patients had statistically signicant relief (dened as
>50% relief) at 3, 6, and 12 months. Most patients received four
injections of bupivacaine with or without 1 mL of Sarapin and
1 mg of methylprednisolone per milliliter of solution with 1 to
1.5 mL of solution injected per nerve. In the second study of 48
patients with positive dual blocks, 24 patients received bupivacaine, and 20 patients received bupivacaine plus betamethasone.
Statistically signicant (>50%) pain relief was reported in both
groups at all time points up to 1 year. In the systematic review
of radiofrequency neurotomy, only two studies were on thoracic
medial branch neurotomy; however, both were of low quality
and failed to meet inclusion criteria for the review because of
Chapter 16 Targeting Pain Generators 279
lack of diagnosis by controlled blocks, small patient sample, and
other methodologic shortcomings.28 More research is needed in
regard to diagnosis and treatment of thoracic pain so that the
evidence can be graded and systematically reviewed, the caveat
being that a lack of evidence is not equivalent to no evidence.
Summary
Chronic disabling spinal pain in a patient suggestive of “facet
(zygapophyseal joint) syndrome” that is unresponsive to usual
care may be considered for diagnostic comparative MBBs,
with low-volume MBBs favored due to superior evidence for
diagnostic specicity. e levels to be investigated are typically
chosen by pain referral patterns described by the patient,
which are correlated with validated zygapophyseal joint pain
referral patterns. Upper neck pain and headache are most
commonly caused by the C2–C3 zygapophyseal joint, and
neck pain with shoulder girdle pain is most commonly caused
by the C5–C6 zygapophyseal joint. e clinician should not
neglect the C0–C1 and C1–C2 articulations as potential pain
generators, in which case diagnostic intraarticular blocks
would be used to help conrm or refute the diagnosis. Evaluation of the exact level of thoracic zygapophyseal joint pain
can be more challenging because pain may be referred over
more than three segments. Lumbar zygapophyseal joint referral patterns are also reported in the literature; zygapophyseal
joint pain may be localized or referred to the buttocks and
lower extremity.
Although comparative double blocks are considered the
reference standard for diagnosis, routine history, physical
examination, radiographs, and advanced imaging should be
obtained for completeness. e clinician oen nds elements
that rule out zygapophyseal joint syndrome and are more
suggestive of disc pathology, radiculopathy, or “red ag”
conditions that require dierent diagnostic and treatment
methods. ere are also cases in which a history of trauma,
particularly whiplash, is highly suggestive of pain of zygapophyseal joint origin, with a known greater than 50% prevalence in the cervical spine. Certain specic imaging ndings,
if present, also may suggest zygapophyseal joint syndrome,
such as a positive SPECT scan, approximately 2 mm edema
on axial MRI of lumbar zygapophyseal joints, or a single
zygapophyseal joint with markedly deforming arthropathy
compared with other joints.
With regard to testing protocol, whether to perform MBBs,
intraarticular zygapophyseal joint injections, or both varies
depending on the situation and preference of the physician. If
one is conrming zygapophyseal joint–mediated pain in
preparation for possible medial branch neurotomy, one could
argue that MBB should be the method of choice due to
improved specicity. If radiofrequency denervation of the
zygapophyseal joint is not planned or SPECT scan imaging
shows edema, intraarticular block is reasonable. In the case of
C0–C1 and C1–C2, intraarticular injections are the only
practical method of diagnosing zygapophyseal joint pain.
As noted earlier, preprocedural and postprocedural evaluation should be performed by unbiased personnel and checked
by the physician using standardized instruments. Evaluation
aer the procedure includes VAS of standard provocative
maneuvers and positions, as well as a report of subjective
percent relief of pain. Ideally, the patient would be tested at
approximately 30 minutes aer lidocaine block and approximately 40 to 60 minutes aer bupivacaine block. Ideally, a pain
diary over the 6 to 8 hours following the block procedure is
recorded by the patient and then reported the following day
in order to decrease recall bias. However, retesting at 2 to 3
hours postinjection is a more reliable protocol. A subject
should have at least 70% to 80% relief for a positive response
to be considered; at least 80% relief is more convincing.
Usually, two to three levels are evaluated per session. Depending on the importance of refuting or conrming whether a
particular zygapophyseal joint is symptomatic, one may select
fewer joints if needed.
Several technical parameters must be met to obtain useful
diagnostic information. Diagnostic volumes must be appropriate. Contrast medium will conrm accurate target identication. For intraarticular zygapophyseal joint blocks, injection
volumes should be limited to 0.3 mL, 0.75 mL, and 1 mL in
the cervical, thoracic, and lumbar spine, respectively. For
MBBs, needle position may be conrmed with injection of a
small volume (0.3–0.5 mL) of contrast dye and the same
volume of local anesthetic. e interventionalist should
observe for venous uptake or undesirable ow patterns. If
there is venous uptake, there is only a 50% chance of successfully anesthetizing the joint; thus, the interventionalist may
consider bringing the patient back at a later date or interpreting the results of the block accordingly.
Infection may occur aer any interventional procedure.
Various infections are reported aer zygapophyseal joint
injections, including paraspinal abscess,
joint abscess,
170
osteomyelitis,
171
and epidural abscess.
169
zygapophyseal
172
In
addition to infections, subdural injections or injection into the
spinal cord may occur. A case of transient tetraplegia
173
was
reported during a cervical zygapophyseal joint injection performed without uoroscopy and most likely was an accidental
subdural injection of local anesthetic. Even when using uoroscopy, there is a risk of accidental subdural injection or
potential spinal cord injection. e danger is especially real
when performing cervical intraarticular injection using a
lateral technique. Using this technique, the needle is passed
laterally using a lateral uoroscopy view. If the anteroposterior
view is not periodically checked, one may not recognize
passage of the needle through the zygapophyseal joint and
dura and then into the cord. In a thin individual, the cord may
be reached with a 1-inch needle. Keeping the needle directly
over the inferior or superior zygapophyseal joint and touching
the bone before entering the joint helps the interventionalist
avoid accidentally entering the spinal canal.
Sacroiliac Joint
With the gradual acceptance of local anesthetic block relief
aer uoroscopy-guided sacroiliac joint blocks as the reference standard for diagnosis, there is a renewed interest in the
sacroiliac joint as a legitimate source of chronic pain.26 e
degree of impact on health is the same as that of radiculopathy,
SECTION
II
280 DIAGNOSIS
as evidenced by statistically similar scores in health-related
quality-of-life testing instruments between patients with a
diagnosis of sacroiliac joint pain and patients with a diagnosis
of radiculopathy.
161
Similar to zygapophyseal joint and discogenic pain, the
diagnosis of sacroiliac joint pain depends on the reference
standard used (and the particular population studied) to
conrm the diagnosis. Society guidelines most oen require
a placebo control or dierential blockade with 50% to 90%
3,147,174
relief.
Typically, a dierential duration of reported pain
relief of lidocaine (approximately 2–3 hours) compared with
bupivacaine (approximately 4–6 hours) is required. Although
concordant provocation of pain during joint arthrography has
been used as an additional requirement, the high percentage
of asymptomatic patients reporting pain during sacroiliac
joint injection implies that provocation has a high falsepositive potential. Currently, using the dual-block paradigm,
the best estimates of prevalence of sacroiliac joint–mediated
pain in patients with low back symptoms range from 10% to
38%, but the lower end of this range is likely most accurate.
175,176
For single, uncontrolled sacroiliac joint injections, the falsepositive rate is 20% to 54%.
177–181
Pathophysiology
e sacroiliac joint has long been recognized as a synovial,
uid-lled diarthrodial joint between the sacrum and ilia with
thick, 6-mm sacral cartilage and thinner, approximately 1-mm
iliac cartilage (Fig. 16.13). e joint is auricular or C-shaped,
with the convex side of the “C” facing anteriorly and inferiorly
(Fig. 16.14).
a thickened capsule, the posterior capsule blends into the
extensive, thick posterior ligamentous structures, which bind
the sacrum to the spine and bilaterally to the ilia. Aer puberty,
the iliac surface develops a convex ridge and the sacral surface
develops a corresponding concave depression. ese articular
182
Although the anterior portion is no more than
surfaces allow slight movement between the contiguous bony
surfaces.
Although early in life gliding motions in all directions are
permitted, by the middle of the second decade of life, the joints
develop prominent ridges centrally along the entire length of
the iliac surface and a corresponding groove along the sacral
surface. Bowen and Cassidy
182
believed that this interdigitation of the joint surfaces restricts motion to a sagittal rotation
or posterosuperior-anteroinferior “nodding” along the crest of
the interdigitations. e motion is complex, however, and
usually limited to less than 4 degrees of rotation and less than
1.6 mm of translation. Signicant motion occurs only aer
severing the interosseous ligament.
183
It is unclear whether a
type or degree of sacroiliac joint motion causes pain in older
individuals. Beyond the sixth decade, cadaveric specimens
commonly show a central region of ossication of the interos-
seous sacroiliac ligament and the presence of ridges and
depressions, which likely result in little to no movement of the
sacroiliac joint in these older individuals.
restriction by periarticular osteophyte formation, intraarticular bony ankylosis appears rare.
182
184
Although there is
Several investigators have studied the innervation of the
sacroiliac joint. Nakagawa
185
reported innervation from the
ventral rami of L4 and L5; the superior gluteal nerve; and
the dorsal rami of L5, S1, and S2. An anatomic dissection of
the innervation of the sacroiliac joint was performed by Yin
and colleagues
186
for the purpose of dening the exact position of the nerves for “sensory stimulation–guided sacroiliac
joint radiofrequency neurotomy.” ese authors dissected
cadavers and placed small-gauge wires adjacent to the lateral
branch nerves entering the joint and over the dorsal sacrum
to the dorsal sacral foramen from S1 to S3. In 1988, Willard
reported dissection of 10 cadavers, which revealed that the S1
and S2 lateral branches provide the primary innervation of
the sacroiliac joint and associated dorsal ligaments. An occasional contribution was found by S3 but not S4. Predominant
187
Inferior
capsular
recess
FIG. 16.13 Anteroposterior view of left sacroiliac joint injection. Note
contrast dye lling the capsule, including the inferior capsular recess
(arrows). (Courtesy Richard Derby, MD.)
FIG. 16.14 Lateral view of sacroiliac joint injection. Note contrast dye lling
the joint space. Also, note the C shape of the joint facing anteriorly (arrows).
(Courtesy Richard Derby, MD.)
Chapter 16 Targeting Pain Generators 281
innervation from lateral branches of S1 was also reported
by Grob and colleagues.
188
ese authors found that dorsal
nerves derived from S1–S4 exclusively innervated the sacroiliac joint and associated ligaments. Nerves were distributed
to supercial and deep dorsal sacroiliac ligaments and to the
sacrotuberous and sacrospinous ligaments. Emerging from
the sacral foramen, the nerves course laterally, sandwiched
between supercial and deep portions of the sacroiliac ligaments. ere is a great variability in the location and number
of lateral branch nerves side to side and between individuals.
186
Due to this variability, the current standard for blocking the
posterior sacroiliac joint as associated dorsal ligaments is to
block the L5 dorsal ramus and S1–S3 lateral branches using
a multisite, multidepth technique described by Dreyfuss and
colleagues.
Berthelot and colleagues
189
190
used the term sacroiliac joint
lato-sensu to describe pain from the sacroiliac joint that may
be emanating from adjoining ligaments rather than simply the
synovial joint. ese ligaments include the iliolumbar ligaments, dorsal and ventral sacroiliac ligaments, and sacrospinous and sacrotuberous ligaments. e prevalence of pain
originating from these structures has received little formal
study, and there is no validated technique to diagnose ligamentous pain. Nevertheless, sacroiliac joint ligamentous pain
is proclaimed as a frequent primary source of low back and
buttock pain by orthopaedists.
191
More important, a negative
response to a sacroiliac joint injection does not mean that pain
does not originate from the iliolumbar ligament and sacroiliac
joint ligaments. A more recent histologic study found calcitonin gene-related peptide and substance P immunoreactive
nerve bers in the normal sacroiliac joint anterior capsular
ligament and interosseous ligament. e authors of the study
opined that diagnostic inltration techniques for sacroiliac
joint pain should employ extraarticular and intraarticular
approaches.
192
In contrast to the zygapophyseal joints, the sacroiliac joint
supporting ligaments are thick, and intraarticularly injected
local anesthetic may not adequately diuse into the sacroiliac
ligaments. Using a single or comparative block protocol, one
can investigate sacroiliac joint ligaments by uoroscopically
guided injections of local anesthetics into the ligaments. Ligamentous injections have not undergone rigorous academic
inquiry, however, and because the injections are rarely or
poorly reimbursed by third-party payers and treatment of
ligamentous laxity typically involves unreimbursed “prolotherapy,” there is little incentive for expensive investigations.
e information is important, however, and dierential pain
arising from the sacroiliac joint versus sacroiliac joint ligaments is reported.
In a comparative study, Murakami and colleagues
193
performed periarticular injections in 25 patients and intraarticular
injections in another 25 patients. Periarticular injections
relieved, on average, 92% pain in 100% of the injected patients
compared with only 9 of 25 patients receiving intraarticular
injections. All 16 patients not receiving relief by intraarticular
injections were improved aer periarticular injections. e
presence of other structural abnormalities does not rule out
the sacroiliac joint as a primary source of pain. Weksler and
colleagues
194
studied 55 patients with herniated discs with
axial and referred leg pain, without objective neurologic de-
cits but with positive sacroiliac provocation tests. Using
intraarticular injection of local anesthetic as the reference
standard, the mean baseline VAS pain score decreased 30
minutes aer injection, from 7.8 to 1.3. In 46 patients 8 weeks
aer injection, VAS scores ranged from 0 to 3.
e question of whether fusion surgery leads to increased
stress on the sacroiliac joint and may be a cause of failed back
surgery syndrome was rst raised by Frymoyer and col-
leagues,
195
although their method of assessing sacroiliac joint
pathology yielded a negative result. In 1978, Frymoyer and
colleagues
195
evaluated patients with radiographs (no diagnos-
tic blocks) 10 years aer posterior fusion versus postdiscec-
tomy and found no signicant dierence in radiographic
abnormalities; they opined that sacroiliac pain was “noncontributory” to persistent low back pain aer surgery. In their
subject population, they believed that the gra donor site was
a more common pain generator. Fusion to the sacrum might
be expected to stress the sacroiliac joints and lead to late
failures or to early failures owing to undiagnosed sacroiliac
joint pain. Ha and colleagues
196
prospectively examined 37
patients undergoing posterolateral lumbar and lumbosacral
fusions; 22 patients had a oating fusion, and 10 patients had
a lumbosacral fusion. CT scans of the sacroiliac joint were
performed before surgery and at 2 weeks, 1 year, and 5 years
aer surgery and compared with 34 matched controls. e
incidence of sacroiliac joint degeneration was 75% in the
fusion group versus 38.2% in the control group and greater in
patients fused to the sacrum. Both groups reported signicant
improvements in VAS and Oswestry Disability Index scores,
and there was no dierence in scores between the two groups.
More recent research has shown that the sacroiliac joint can
be a signicant source of pain aer fusion. Biomechanical
models seem to support these conclusions. Ivanov and col-
197
leagues
performed a nite-element study with lumbosacral
models and fusion constructs and found that fusion to the
sacrum increased motion and stresses at the sacroiliac joint.
Cadaveric studies show that disruption of the ventral band of
the iliolumbar ligament signicantly increases sacroiliac joint
mobility.
198
Ebraheim and colleagues
199
evaluated the preva-
lence of sacroiliac joint disruption by CT scan in 24 patients
aer fusion with persistent “donor site pain” aer posterior
superior iliac crest gra harvesting. ey found a high prevalence of persistent sacroiliac joint pain in patients with innertable disruption. Patients with violation of the synovial portion
of the sacroiliac joint had severe degenerative changes on CT
versus mild to moderate degeneration with inner-table disruption only. It seems that the original hypothesis by Frymoyer
and colleagues
195
that sacroiliac joint dysfunction was the
cause of donor site pain may have been correct.
What is the evidence for using diagnostic blocks as the
reference standard? Diagnosis of sacroiliac joint pain has been
reported by researchers using single and dual blocks; with
these methods, prevalence rates of sacroiliac joint pain aer
lumbar fusion range from 27% to 35%. Maigne and Plan-
200
chon
studied 40 patients aer fusion with continued pain
using 75% pain relief aer a single sacroiliac joint intraarticular
SECTION
II
282 DIAGNOSIS
injection as the gold standard. ey reported a 35% rate of
positive blocks. e only characteristic that distinguished the
positive from the negative responders was a dierent distribution of postoperative pain compared with preoperative pain.
A pain-free interval of 3 months aer surgery was signicant;
however, increased uptake in the sacroiliac joint on bone
scintigraphy or posterior iliac bone gra harvesting was not
signicant.
Katz and colleagues
201
studied 34 patients aer lumbosacral
fusion with continued pain thought to be due to the sacroiliac
joint with intraarticular injections of local anesthetic and
corticosteroids. Eleven patients (32%) had greater than 75%
pain relief with local anesthetic and a minimum of 10 days of
continued pain relief (with steroid) and were considered to
have denite sacroiliac joint pain. Another 10 patients (29%)
had greater than 75% relief with local anesthetic but no longterm relief. ere was no correlation between the donor site
and pain side. Irwin and colleagues
177
used dual comparative
sacroiliac joint blocks as the reference standard to dene
sacroiliac joint pain and found that the 27% of positive
responders tended to be older. ey found no statistical relationship between age, body mass index, and gender.
Diagnostic Accuracy of Clinical History and Physical Examination for Sacroiliac Pain
e diagnostic utility of history and accepted sacroiliac joint
physical examination tests was rst rigorously examined by
Dreyfuss and colleagues in 1996.
to determine if any single or combination of 12 history and
physical examination ndings could predict intraarticular
sacroiliac joint pain as judged against a single positive intraarticular sacroiliac joint block with greater than 90% pain relief.
In 85 patients, there were 45 positive blocks. None of the 12
physical examination tests, the presence of 5 to 12 positive
tests, or any combination of these 12 tests correlated with the
presence of sacroiliac joint pain. One important historical
feature was notable, however: only 2 of 45 patients drew pain
above the L5 level, suggesting that pain below L5 is more likely
to be of sacroiliac joint origin. Maigne and colleagues
reached a similar conclusion using dual comparative blocks:
no single provocation test reached statistical signicance in
the 10 patients (18.5%) who had temporary pain relief on the
conrmatory injection.
Although no single provocative maneuver has been shown
to be of diagnostic value, using the dual-block paradigm,
several studies have obtained highly acceptable sensitivity
(85–91%) and specicity (78–79%) rates by combining three
or more sacroiliac joint pain provocation tests for diagnosis
by physical examination.
variation in the tests used by various authors but, in summary,
they include the following provocation tests: thigh thrust,
distraction test, Gaenslen test, Patrick sign, compression test,
midline sacral thrust test, and heel drop test. Specicity
increased to 87% if the patient’s pain did not centralize or
could not be made to move toward the spinal midline (which
is typical of discogenic pain).
tion tests (distraction, compression, thigh thrust, Patrick sign,
202
eir study was designed
12,178,179,181,203
204
ere is some slight
When three or more provoca-
176
Gaenslen test) are negative, the likelihood of sacroiliac joint
pain is very low (6–15%); when all provocation tests are negative, the sacroiliac joint was never the source of pain.
With regard to pain referral maps, Slipman and colleagues
and Dreyfuss and colleagues
202
concluded that of all alleged
signs of sacroiliac joint pain, maximum pain below L5 coupled
with pointing to the posterior superior iliac spine or tenderness just medial to the posterior superior iliac spine (sacral
sulcus tenderness) has the highest positive predictive value of
60% of true sacroiliac joint–mediated pain; if these do not
exist, the likelihood of sacroiliac joint pain is less than 10%. It
must be noted that sacroiliac joint pain can refer into various
aspects of the lower extremity, with 94% of patients reporting
buttock pain, 48% reporting thigh pain, and 28% reporting
lower leg pain (Fig. 16.15).
175,176,206
However, referral to the
lower extremity may not always be reliably distinguished from
other pain sources (e.g., S1 radiculopathy).
175,207
Last, although pain referral patterns between responders
and nonresponders are similar, Fortin and colleagues
described an area of pain approximately 3 × 10 cm just inferior
to the posterior superior iliac spine that was common in all
subjects with sacroiliac joint pain. More recently, Murakami
and colleagues
209
studied the specicity and sensitivity of the
“Fortin” point with periarticular injections. Labeled the one
nger test, 18 of 38 patients pointed to a location of pain at the
posterior superior iliac spine or within 2 cm of the posterior
superior iliac spine, which had a positive response to periarticular sacroiliac joint block. e authors recommended that
sacroiliac joint pain should be considered in patients who can
point to their pain using one nger in the vicinity of the
posterior superior iliac spine.
Systematic reviews report various conclusions regarding
the specicity of the physical examination and sacroiliac joint
0.5+
0.5+
4+
1+
1+
2+ 2+
1.5+
1.5+
1+ 1+
FIG. 16.15 Density of referral zones for sacroiliac joint pain. 0.5+ is the least
common referral zone; 4+ is the most common referral zone. (From Dreyfuss
P, Dreyer S. Sacroiliac joint pain. J Am Acad Orthop Surg. 2004;12:255–265.)
4+
3+
1.5+
1+ 1+
3+
1.5+
178,179,181,204
205
208