Article

Weishaupt D, Zanetti M, Hodler J, et al. Painful Lumbar Disk Derangement: Relevance of Endplate Abnormalities at MR Imaging

Departments of Radiology, Orthopaedic University Hospital Balgrist, Zurich, Switzerland.
Radiology (Impact Factor: 6.87). 03/2001; 218(2):420-7. DOI: 10.1148/radiology.218.2.r01fe15420
Source: PubMed

ABSTRACT

To investigate the predictive value of magnetic resonance (MR) imaging of abnormalities of the lumbar intervertebral disks, particularly with adjacent endplate changes, to predict symptomatic disk derangement, with discography as the standard.
Fifty patients aged 28-50 years with chronic low back pain and without radicular leg pain underwent prospective clinical examination and sagittal T1- and T2-weighted and transverse T2-weighted MR imaging. Subsequently, patients underwent lumbar discography with a pain provocation test (116 disks). MR images were evaluated for disk degeneration, a high-signal-intensity zone, and endplate abnormalities. Results of pain provocation at discography were rated independently of the image findings as concordant or as nonconcordant or painless. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated to assess the clinical relevance of MR abnormalities.
Normal disks on MR images were generally not painful at provocative discography (NPV, 98%). Disk degeneration (sensitivity, 98%; specificity, 59%; PPV, 63%) and a high-signal-intensity zone (sensitivity, 27%; specificity, 85%; PPV, 56%) were not helpful in the identification of symptomatic disk derangement. When only moderate and severe type I and type II endplate abnormalities were considered abnormal, all injected disks caused concordant pain with provocation (sensitivity, 38%; specificity, 100%; PPV, 100%).
Moderate and severe endplate abnormalities appear be useful in the prediction of painful disk derangement in patients with symptomatic low back pain.

Full-text

Available from: Marco Zanetti
Dominik Weishaupt, MD
Marco Zanetti, MD
Juerg Hodler, MD
Kan Min, MD
Bruno Fuchs, MD
Christian W. A. Pfirrmann,
MD
Norbert Boos, MD
Index terms:
Spine, abnormalities, 336.77, 336.78
Spine, intervertebral disks, 336.77,
336.78
Spine, MR, 33.121411
Radiology 2001; 218:420427
Abbreviations:
NPV negative predictive value
PPV positive predictive value
1
From the Departments of Radiology
(D.W., M.Z., J.H.) and Orthopaedic Sur-
gery (K.M., B.F., C.W.A.P., N.B.), Ortho-
paedic University Hospital Balgrist, Zu-
rich, Switzerland. Received February 29,
2000; revision requested April 10; revi-
sion received June 2; accepted June 30.
Address correspondence to D.W., In-
stitute of Diagnostic Radiology, Uni-
versity Hospital Zurich, Raemistrasse
100, 8091 Zurich, Switzerland (e-mail:
Dominik.Weishaupt@dmr.usz.ch).
©
RSNA, 2001
Author contributions:
Guarantors of integrity of entire study,
D.W., N.B.; study concepts and de-
sign, M.Z., J.H., N.B.; definition of in-
tellectual content, M.Z., J.H., N.B.; lit-
erature research, D.W., N.B.; clinical
studies, D.W., K.M., B.F., C.W.A.P.;
data acquisition, D.W., K.M., B.F.,
C.W.A.P.; data analysis, J.H., M.Z.,
N.B.; statistical analysis, N.B., D.W.;
manuscript preparation and editing,
D.W., N.B.; manuscript review, M.Z.,
J.H., K.M., B.F., N.B.; manuscript final
version approval, D.W., N.B.
Painful Lumbar Disk
Derangement: Relevance
of Endplate Abnormalities
at MR Imaging
1
PURPOSE: To investigate the predictive value of magnetic resonance (MR) imaging
of abnormalities of the lumbar intervertebral disks, particularly with adjacent end-
plate changes, to predict symptomatic disk derangement, with discography as the
standard.
MATERIALS AND METHODS: Fifty patients aged 28 –50 years with chronic low
back pain and without radicular leg pain underwent prospective clinical examina-
tion and sagittal T1- and T2-weighted and transverse T2-weighted MR imaging.
Subsequently, patients underwent lumbar discography with a pain provocation test
(116 disks). MR images were evaluated for disk degeneration, a high-signal-intensity
zone, and endplate abnormalities. Results of pain provocation at discography were
rated independently of the image findings as concordant or as nonconcordant or
painless. Sensitivity, specificity, positive predictive value (PPV), and negative predic-
tive value (NPV) were calculated to assess the clinical relevance of MR abnormalities.
RESULTS: Normal disks on MR images were generally not painful at provocative
discography (NPV, 98%). Disk degeneration (sensitivity, 98%; specificity, 59%; PPV,
63%) and a high-signal-intensity zone (sensitivity, 27%; specificity, 85%; PPV, 56%)
were not helpful in the identification of symptomatic disk derangement. When only
moderate and severe type I and type II endplate abnormalities were considered
abnormal, all injected disks caused concordant pain with provocation (sensitivity,
38%; specificity, 100%; PPV, 100%).
CONCLUSION: Moderate and severe endplate abnormalities appear be useful in the
prediction of painful disk derangement in patients with symptomatic low back pain.
There is general agreement that an extruded or sequestered disk with nerve compression
seen on magnetic resonance (MR) images in a patient with acute radicular leg pain is a
plausible explanation for the patient’s pain. However, to our knowledge, the clinical
relevance of other MR findings, including disk degeneration in patients with low back
pain, remains unknown. When one considers the well-documented pathologic evidence
of disk degeneration and herniation in the early decades of life and their increased
prevalence with advancing age (1), it is not surprising that disk abnormalities are fre-
quently depicted on MR images obtained in asymptomatic volunteers. Findings of several
studies (2-6) have shown the occurrence of a wide spectrum of disk abnormalities, includ-
ing disk degeneration, disk bulging, disk protrusion, and annular tears, as evidenced by
high-signal-intensity zones in a substantial percentage of healthy volunteers.
In contrast, abnormalities of the endplate and adjacent bone marrow described by
Modic et al (7,8) have been shown (6) to be uncommon in asymptomatic volunteers aged
20–50 years. Findings in two recent publications (9,10) suggested a possible relationship
between endplate abnormalities revealed at MR imaging and discogenic pain.
The aim of this study was to determine the predictive value of MR imaging abnormal-
ities, including disk degeneration, annular tears (ie, high-signal-intensity zones), and
abnormalities of the endplate and adjacent bone marrow of the lumbar spine for symp-
tomatic disk derangement, with discography as the standard.
420
Page 1
MATERIALS AND METHODS
Study Population
Within the 20 months from January
1998 to August 1999, 50 consecutive pa-
tients (23 women, 27 men; mean age,
42.4 years; age range, 28 –50 years) were
prospectively enrolled in the study. All
patients underwent both MR imaging of
the lumbar spine and lumbar discogra-
phy as part of a clinical evaluation of low
back pain. MR imaging preceded discog-
raphy in all patients. Inclusion was based
on fulfillment of all of the following cri-
teria:
1. Severe chronic low back pain of pre-
sumably discogenic origin (eg, pain ag-
gravation with forward bending, pain
during the night, and pain during pro-
longed sitting with or without referred
leg pain [pseudoradicular leg pain into
the anterior thigh]). Severe chronic low
back pain was defined as low back pain
that persisted for longer than 6 weeks
and that was unresponsive to a trial of
nonsurgical treatment, with surgery not
indicated or not urgent on the basis of
clinical findings.
2. Severe interference of the back pain
with lifestyle and failure of an adequate
trial of nonsurgical treatment of at least 6
months duration (ie, a potential indica-
tion for surgery in the case of pain prov-
ocation during discography).
3. Appropriateness of the candidate for
surgery in the case of positive findings at
discography.
Primary exclusion criteria were based
on clinical findings, which included ra-
dicular leg pain, neurologic deficits or ev-
idence of neurogenic claudication, and
inappropriate illness behavior as defined
by the criteria of Waddell et al (11). The
criteria for inappropriate illness behavior
included inappropriate descriptions of
symptoms and inappropriate responses
at physical examination of chronic low
back pain.
Secondary exclusion criteria were based
on MR imaging findings in the lumbar
spine and included a normal MR image
or the presence of disk extrusion or se-
questration, nerve root compression, fo-
raminal or central spinal stenosis, sus-
pected spinal infection or neoplasm,
spondylolisthesis, and moderate to se-
vere facet joint osteoarthritis as revealed
with the imaging studies. The secondary
exclusion criteria were chosen to exclude
patients with MR imaging findings that
were currently considered to be a poten-
tial source of nondiscogenic low back
pain.
All MR images were reviewed prior to
the patient’s inclusion into the study by
two musculoskeletal radiologists working
in consensus. The two radiologists who
performed the initial MR evaluation were
not involved further in the study.
During this initial MR evaluation, the
following terms for disk abnormalities
were used: normal, bulging, protrusion,
extrusion, and sequestration (12,13).
Since the presence of disk bulging and
protrusion did not represent a secondary
exclusion criterion, patients with these
MR imaging findings were included in
the study. Severity of facet joint osteoar-
thritis was based on MR findings and
were classified as mild, moderate, or se-
vere by using recently published criteria
(14). This classification of severity of
facet joint osteoarthritis has been shown
(14) to have a good inter- and intraob-
server correlation when simultaneously
used with computed tomography and
MR imaging.
The aforementioned diagnostic workup
represents the current standard procedure
in our spine service. Besides prospective
data assessment and evaluation, no addi-
tional clinical procedures were performed
for the purpose of the study. In accordance
with the hospital’s institutional review
board, informed consent was obtained
prior to both MR imaging and lumbar dis-
cography.
MR Imaging
MR imaging was performed with a 1.0-T
unit (Impact Expert; Siemens, Erlangen,
Germany) with a dedicated receive-only
spine coil. The imaging protocol consisted
of sagittal T1-weighted (700/12 [repetition
time msec/echo time msec]) and sagittal
T2-weighted (5,000/112) turbo spin-echo
imaging of the entire lumbar spine. The
image matrix was 512 210 or 512 192;
field of view, 300 225 or 300 180 mm;
section thickness, 4 mm; intersection gap,
0.5 mm; and echo train length, three or 15.
In addition, transverse T2-weighted turbo
spin-echo images (4,000/96; image matrix,
512 192; field of view, 150 mm; section
thickness, 4 mm; intersection gap, 0.5 mm;
echo train length, seven) were obtained of
all abnormal disk levels and of at least one
disk level with a normal MR appearance.
Lumbar Discography
All 50 patients underwent provocative
discography of all abnormal interverte-
bral disks, as defined by the radiologists
involved in the initial evaluation of MR
images. In patients with concordant pain
(see Pain Assessment for definition) at
discography, a disk with a normal ap-
pearance on MR images was also injected.
Evaluation of these presumably healthy
disks served as an internal control.
An orthopedic spine surgeon (N.B.) per-
formed discography in the surgical theater
with use of fluoroscopy. The mean delay
between MR imaging and discography was
27 days (range, 1–166 days). The patient
was awake throughout the procedure and
did not receive a sedative. Discography was
carried out with a standard posterolateral
approach by using a 22-gauge needle (Bec-
ton Dickson, Franklin Lakes, NJ). In pa-
tients with unilateral pain, the needle was
always introduced from the side opposite
the area of the pain; in patients with bilat-
eral pain, we preferred to use the left side
for convenience. Needle position was veri-
fied with fluoroscopic control in two
planes. After accurate needle positioning,
iopamidol (Iopamiro 300; Sintetica, Men-
drisio, Switzerland) containing an iodine
concentration of 300 mg/mL was injected
into each disk by using a 5-mL syringe. The
amount of contrast agent injected ranged
from 0.8 to 4.0 mL. Nonionic contrast
agent (iopamidol [Iopamiro 300]; Sintetica,
Mendrisio, Switzerland) was injected with
a 5-mL syringe until firm resistance to the
injection was felt, until severe pain was
provoked, or until contrast medium was
seen to leak out of the disk into the spinal
canal.
MR Image Evaluation
MR images in all 50 patients were eval-
uated together by two experienced mus-
culoskeletal radiologists (M.Z., J.H.) not
involved in decision making for treat-
ment. The observers were completely
blinded to patient data and clinical and
discographic findings. All images were
evaluated in random order. A consensus
opinion was reached in all cases of dis-
agreement between the two observers.
Intra- and interrater reliability estimates
for the identical readers were reported in
a previous study (14) in which the same
criteria were used. The evaluated MR im-
aging findings included extent of inter-
vertebral disk degeneration, presence of a
high-signal-intensity zone in the poste-
rior aspect of the anulus fibrosus, and
abnormalities of the endplates and adja-
cent bone marrow.
The extent of intervertebral disk de-
generation was graded on midsagittal T2-
weighted images according to the criteria
of Eyre et al (15) and Pearce et al (16)
(Table 1). For the purpose of this study,
disks with grades 1 (normal adolescent
Volume 218
Number 2 Painful Lumbar Disk Derangement
421
Page 2
disk) and 2 (normal adult disk) were
grouped together as disks without de-
generation. Similarly, disks with grades
3–5 (grade 3, slight degeneration; grade
4, moderate degeneration; and grade 5,
severe degeneration) were grouped to-
gether as degenerated disks.
The presence of a high-signal-intensity
zone was noted on sagittal T2-weighted
turbo spin-echo images. A high-signal-
intensity zone was defined as a focal zone
of high signal intensity within the poste-
rior aspect of the anulus fibrosus that was
clearly dissociated from the pulpy nu-
cleus, without focal protrusion or extru-
sion of the disk (17). The high-signal-
intensity zone has been reported (17) to
represent annular tears.
The readers were asked to classify the
endplates and adjacent bone marrow ab-
normality on sagittal MR images accord-
ing to the definitions of Modic et al (7,8)
for each category as follows: no abnor-
mality; type I, low signal intensity on
T1-weighted images and high signal in-
tensity on T2-weighted images when
compared with fatty bone marrow; type
II, high signal intensity with both im-
ages; and type III, low signal intensity
with both images. When two types were
present on both sides of the interverte-
bral space, only one diagnosis was ap-
plied: first priority, type I; second prior-
ity, type II; last priority, type III.
In the presence of an endplate abnor-
mality, the readers were asked to grade
the abnormality with regard to extent as
follows: none, minimal, moderate, or se-
vere (Figs 1–3). Severity of endplate ab-
normalities was defined as follows: none,
no evidence of endplate abnormalities
on both T1- and T2-weighted images;
minimal, largest cranial or caudal extent
of endplate abnormality involving equal
to or less than 25% of the vertebral
height as measured on a midsagittal im-
age; moderate, largest cranial or caudal
extent of the endplate abnormality be-
tween 25% and 50% of the vertebral
height measured on a midsagittal image;
or severe, largest cranial or caudal extent
equal to or more than 50% of the verte-
bral height as measured on a midsagittal
MR image (Figs 1–3). When endplate ab-
normalities were present on both sides of
the intervertebral disk, the endplate ab-
normality with the larger cranial or cau-
dal extent was used for further evalua-
tion.
Pain Assessment
During discography, patients were
asked to grade the pain they experienced
on a scale of 0 (no pain or pressure) to 10
(worst pain imaginable). They were fur-
ther asked to grade the pain according to
the Dallas Discogram Description (18) as
no sensation, pressure, dissimilar pain,
similar pain, or exact pain reproduction.
For the purpose of this study, pain sensa-
tion during discography was defined as
concordant if the patient had exact pain
reproduction or felt similar pain. Accord-
ingly, nonconcordant pain was defined
as pressure, dissimilar pain sensation, or
no pain provocation.
Morphologic Discogram Evaluation
Each discogram was reviewed by the
orthopedic spine surgeon who performed
discography. Evaluation of disk morpho-
logic characteristics was performed with
conventional radiographs by using the
classification of Adams et al (19). This
Figure 1. MR images of the lumbar spine in a 32-year-old woman with discogenic low back pain
demonstrate the criteria used to identify mild endplate abnormalities. Sagittal (a) T1-weighted
(700/12) and (b) T2-weighted (5,000/112) turbo spin-echo MR images demonstrate a small band
of increased signal intensity (arrowheads) of bone marrow (cranial or caudal extent 25% of the
vertebral height as measured on a midsagittal image) adjacent to the upper endplate at the
intervertebral disk level of L5 (5)toS1(1) (type II endplate abnormality). There is grade 3
degeneration at the L5-to-S1 intervertebral disk level with disk bulging and grade 4 degeneration
of the intervertebral disk at L4 (4) to L5 with disk bulging.
TABLE 1
Classification of Disk Degeneration on Sagittal T2-weighted MR Images
Grade
Differentiation
of Nucleus
Pulposus from
Anulus Signal Intensity of Nucleus Pulposus Disk Height
1 Yes Homogeneously hyperintense Normal
2 Yes Hyperintense with horizontal dark band Normal
3 Blurred Slightly decreased, minor irregularities Slightly decreased
4 Lost Moderately decreased, hypointense zones Moderately decreased
5 Lost Hypointense, with or without horizontal
hyperintense band
Collapsed
Note.—Modified from the classification of Pearce et al (16).
422
Radiology
February 2001 Weishaupt et al
Page 3
classification system includes five stages
of disk degeneration distinguished by
their morphologic appearance on disco-
grams. For the purpose of this study,
disks of nondegenerative types I (cotton
ball) and II (lobular) were grouped to-
gether as normal; those of types III (irreg-
ular), IV (fissured), and V (ruptured) were
grouped as degenerative (ie, abnormal)
disks.
Data and Statistical Analyses
The prevalence of all MR abnormalities
were calculated, and the data were com-
pared with disk morphologic characteris-
tics (19) and pain responses, as evidenced
at discography. The data obtained from
pain assessment during discography was
further used to determine painful disk
derangement. Sensitivity, specificity, posi-
tive predictive value (PPV), negative pre-
dictive value (NPV), and accuracy (20) for
each predictor variable (ie, disk degenera-
tion, high-signal-intensity zone, and end-
plate abnormalities) were calculated; the
result of the pain response during discog-
raphy was the standard.
RESULTS
A total of 122 disks in 50 patients were
included in this study. The L5-to-S1 level
was not accessible in six patients, and
they were therefore excluded from the
analyses. The results of the injection at
the L5-to-S1 level would not have influ-
enced the treatment decision in any of
these patients. On the other hand, the
L5-to-S1 level was successfully accessed
in all patients in whom the result rele-
vant to the clinical decision. Therefore,
discography was performed in 116 disks
in 50 patients, and the following results
were used for further evaluation: eight
(6.9%) disks at the L2-to-L3 level, 34
(29.3%) at the L3-to-L4 level, 46 (39.7%)
at the L4-to-L5 level, and 28 (24.1%) at
the L5-to-S1 level.
The prevalence of discographic and
MR imaging findings in the 116 disk lev-
els where discography was performed are
shown in Table 2. On MR images, 37
(31.9%) of 116 disks were considered
nondegenerated (grades 1 and 2) normal
disks without any of the assessed abnor-
malities. Disk degeneration, high-signal-
intensity zone, and/or endplate abnor-
malities were present in 79 (68.1%) disks.
No type III endplate abnormality was
present at any disk level.
A comparison of the discographic find-
ings (according to the classification of
Adams et al [19]) and the MR imaging
appearance of the disk revealed no case
of a type IV (fissured) or V (ruptured)
disk when the MR images were normal
(Table 2).
None of the patients who reported con-
cordant pain with provocation graded the
pain intensity below 6 on the 10-point
scale. Sixteen (44%) of 36 patients with
concordant pain reported the worse pain
they ever experienced.
In a subset of 37 patients with concor-
dant pain with provocation, at least one
normal disk on MR images (ie, no disk
degeneration or other MR abnormality)
was injected . All but one patient had a
negative pain provocation test: Twelve
patients had no sensation; 22, only pres-
sure; and two, dissimilar pain. The re-
maining patient reported similar pain
with injection of contrast medium. The
NPV of a normal disk on MR images in
terms of pain provocation was 97% (37 of
38 patients).
Sensitivity, specificity, NPV, PPV, accu-
racy, and disease prevalence are shown in
Table 3. Disk degeneration as seen on MR
images had a high NPV (98%) but a low
specificity (59%) in terms of pain predic-
tion. The presence of a high-signal-inten-
sity zone showed a high specificity (85%)
but a low PPV (56%) in terms of pain re-
production. PPV and specificity of both
type I and type II endplate abnormalities
were 88% and 96%, respectively, when
slight, moderate, and severe endplate
changes were encountered. When only
moderate and severe endplate abnormali-
ties of both type I and type II were consid-
ered abnormal, all injected disks caused con-
cordant pain with provocation (PPV, 100%;
specificity, 100%).
Figure 2. MR images of the lumbar spine in a 46-year-old woman with discogenic low back pain
demonstrate the criteria used to identify moderate endplate abnormalities. Sagittal (a) T1-
weighted (700/12) and (b) T2-weighted (5,000/112) MR images demonstrate a thick semicircular
band of increased signal intensity (upper arrowheads) of bone marrow adjacent to the upper
aspect of the endplate at the intervertebral disk level of L4 (4)toL5(5) (cranial or caudal extent
between 25% and 50% of the vertebral height measured on a midsagittal image) and a small focus
of increased signal intensity (lower arrowhead) of marrow at the inferior aspect of this level.
Image findings are consistent with a moderate type II endplate abnormality. There is grade 3
degeneration at the L4-to-L5 intervertebral disk level with disk bulging and grade 4 degeneration
at the intervertebral disk level of L5 to S1 (1) with mild type II endplate abnormalities (arrows in
b) and disk bulging. 3 L3 vertebra.
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Number 2 Painful Lumbar Disk Derangement
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DISCUSSION
Discogenic pain in the lumbar spine is
common and is characterized by nonra-
dicular pain. Discogenic pain has a soma-
totropic rather than dermatomal pattern
of pain projection (21). Therefore, the
use of symptoms and clinical findings to
localize the level of abnormality is diffi-
cult. The source of discogenic pain is still
unknown. Degeneration of the interver-
tebral disk, annular tears, and endplate
abnormalities have been discussed (8,9,
22,23) as causative factors.
MR imaging provides an unique means
to evaluate the morphologic status of in-
tervertebral disks and their relationship
to neural structures in patients with low
back pain. Moreover, the technique al-
lows assessment of the biochemical sta-
tus of the disk on T2-weighted spin-echo
and fast spin-echo MR images (16). Loss
of disk height and loss of brightness of
the pulpy nucleus reflect the decreased
proteoglycan concentration in degener-
ated disks (16). Yu et al (24) demon-
strated in a postmortem study that with
the use of MR imaging accurate detection
of annular tears is possible. However, al-
though MR imaging provides detailed in-
formation with regard to the whole spec-
trum of abnormalities, the role of MR
imaging in the evaluation of discogenic
pain has not been well defined (25,26).
The clinical relevance of abnormal MR
findings in patients with back pain has
been questioned by several investigators
(2–6) in studies of asymptomatic volun-
teers. In addition, MR imaging often
demonstrates several abnormal interver-
tebral disk levels in symptomatic pa-
tients; thereby, it is not helpful in the
identification of symptomatic interverte-
bral disk levels. Therefore, the question
arises as to which signs on MR images, if
any, can be used to differentiate symp-
tomatic findings from asymptomatic
ones.
Today, MR imaging has surpassed stan-
dard discography in the depiction of
internal disk structure. However, discog-
raphy as a pain provocation test is con-
sidered the only method that can be used
to directly relate a radiologic image to the
patient’s pain (26). This procedure is,
therefore, still the standard in the diag-
nosis of painful disk derangement. The
rationale for back pain is related to the
fact that, during injection of contrast me-
dium into the disk, breakdown products
such as neuropeptides or cytokines are
expelled from the disk and cause noci-
ception at the outer annular fibers that
are innervated (27). With the use of cur-
rent techniques, a specificity of 100%
with discography in the detection of
painful lumbar disks is reported (28).
Prior MR imaging, however, is considered
a prerequisite with regard to determina-
tion of the levels that should be injected
at discography (26).
The results of our study show that the
presence of a degenerated disk on T2-
weighted turbo spin-echo images was not
a reliable marker for a symptomatic disk.
The results are in accordance with those
of Collins et al (29), who reported on a
prospective study of 29 patients with
chronic low back pain who were being
considered for spinal surgery. In the
study by Collins et al (29), all symptom-
atic disks were degenerated at MR imag-
ing (as indicated by decreased signal in-
tensity on T2-weighted images) and at
discography. Of the 57 degenerated disks
detected with discography, only 23%
were symptomatic. The poor predictive
value of a painful disk in the presence of
disk degeneration on MR images is sup-
ported by the results of three other stud-
ies (30-32), as well as the fact that disk
degeneration on MR images has a high
prevalence in healthy volunteers aged
20–50 years (4,6).
The clinical relevance of a posterior
high-signal-intensity zone on T2-weighted
MR images, which is considered to repre-
sent a severe form of a combined radial and
concentric annular tear (17), is controver-
sial. Aprill and Bogduk (17) reported an
86% PPV of a high-signal-intensity zone at
painful discography in 500 patients. The
high PPV of a high-signal-intensity zone
for painful annular tears has been vali-
dated by other investigators (32–34). Con-
versely, Ricketson et al (35) were not able
to demonstrate a statistically significant
correlation between the presence of a high-
signal-intensity zone and pain concordant
with the usual symptoms during provoca-
tive discography. In the current study, the
correlation between the presence of a high-
signal-intensity zone and concordant pain
was low (Fig 4). In light of a prevalence of
Figure 3. MR images of the lumbar spine in a 35-year-old woman demonstrate the criteria used
to identify severe endplate abnormalities. (a) Sagittal T1-weighted (700/12) turbo spin-echo
image shows extensive bone marrow abnormalities of low signal intensity (arrowheads) (cranial
or caudal extent 50% of the vertebral height as measured on a midsagittal MR image) adjacent
to both endplates at the L4-to-L5 disk intervertebral level. (b) Sagittal T2-weighted (5,000/112)
turbo spin-echo image shows an increase in signal intensity (arrowheads) of bone marrow,
consistent with a severe type I endplate abnormality. There is grade 4 degeneration of the
L4-to-L5 intervertebral disk. 1 S1 vertebra, 3 L3 vertebra.
424
Radiology
February 2001 Weishaupt et al
Page 5
56% (5,6), a high-signal-intensity zone may
not be predictive of discogenic pain.
Recently, debate has focused on end-
plate abnormalities as an indicator of
symptomatic disk degeneration. Three
types of such abnormalities have been
described by Modic et al (7,8). Correla-
tions between MR imaging and disco-
graphic findings have suggested that
endplate abnormalities may be predictive
for discogenic pain (9,10). In our study
population, endplate abnormalities were
demonstrated adjacent to 26 disks, 23 of
which produced concordant pain at pro-
vocative discography. When only moder-
ate and severe endplate abnormalities of
types I and II were considered abnormal,
all disks with endplate abnormalities
caused concordant pain, which resulted
in a PPV of 100%.
McCall et al (9) and Braithwaite et al
(10) reported remarkably similar findings
with regard to the prevalence and clinical
relevance of endplate abnormalities in
patients with discogenic pain. In a retro-
spective study of 58 patients with disco-
genic pain, Braithwaite et al (10) found a
prevalence of 48% with endplate abnor-
malities and a PPV of 97% as a marker for
a painful disk. The likelihood of the clin-
ical relevance of endplate abnormalities
in patients with discogenic pain is sup-
ported by the low prevalence of endplate
abnormalities in an asymptomatic popu-
lation (6) of the same age as that of pa-
tients in the present study.
Although our data are encouraging,
preoperative provocative discography
may still be needed to identify symptom-
atic disk derangement, even in patients
with moderate or severe endplate abnor-
malities. The need for discography in the
assessment of patients with discogenic
pain is also substantiated by the fact that
not all discogenic pain is caused by end-
plate abnormalities. Clearly, more data
must be provided until the need for pro-
vocative discography can be eliminated
in patients with presumably discogenic
pain and endplate changes on MR im-
ages.
The cause of endplate abnormalities is
not well understood. Recent data suggest
that they may develop as a result of in-
flammatory alterations within the disk
matrix in symptomatic patients. Boos et
al (36) showed that symptomatic disk
herniations exhibited T1 and T2 relax-
ation times that were substantially lower
than those of matched asymptomatic
TABLE 2
Comparison of Results of MR Imaging and Discography in 116 Disks of 50 Patients with Discogenic Pain
Discographic Findings
No. of
Disks
MR Imaging Findings
Disk Degeneration*
High-Signal-
Intensity
Zone
Endplate Abnormality
Type I Type II
Grades
1–2
Grade
3
Grade
4
Grade
5 All
Only Moderate
and Severe All
Only Moderate
and Severe
Disk Morphology
Type I 16 14 2 0 0 1 1 0 0 0
Type II 25 18 5 2 0 2 0 0 1 0
Type III 22 9 8 4 1 2 2 0 1 1
Type IV 45 0 19 22 4 14 9 8 7 5
Type V 8 0 4 4 0 4 4 3 1 1
Pain response
Nonconcordant pain 68 40 17 10 1 10 2 0 1 0
Concordant pain 48 1 21 22 4 13 14 11 9 7
* Classification by Pearce et al (16).
Classification from Modic et al (7,8).
Classification by Adams et al (19).
TABLE 3
Diagnostic Performance of MR Abnormalities of the Intervertebral Disk in the Prediction of Symptomatic Intervertebral
Disks
MR Abnormalities
Prevalence*
(n 116) TP FN FP TN
Sensitivity
(%)
Specificity
(%) PPV (%) NPV (%) Accuracy (%)
Disk degeneration grades 3–4 75 (64.7) 47 1 28 40 98 59 63 98 75
High-signal-intensity zone 23 (19.8) 13 35 10 58 27 85 56 62 61
Endplate abnormalities
Modic type I
All 16 (13.8) 14 34 2 66 29 97 88 66 69
Only moderate and severe 11 (9.5) 11 37 0 68 23 100 100 65 68
Modic type II
All 10 (8.6) 9 39 1 67 19 98 90 63 65
Only moderate and severe 7 (6.0) 7 41 0 68 15 100 100 62 65
Modic types I and II
All 26 (22.4) 23 25 3 65 48 96 88 72 76
Only moderate and severe 18 (15.5) 18 30 0 68 38 100 100 69 74
Note.—The numbers of false-negative (FN), false-positive (FP), true-negative (TN), and true-positive (TP) findings are based on positive prediction of a
symptomatic intervertebral disk as evidenced by pain response during discography.
* Numbers in parentheses are percentages.
Volume 218
Number 2 Painful Lumbar Disk Derangement
425
Page 6
herniations. The authors concluded that
symptomatic and morphologically matched
asymptomatic disk herniations differ with
regard to disk matrix composition.
This hypothesis has been substantiated
by Burke et al (37) who biochemically
examined disk specimens that were har-
vested during discectomy for seques-
trated disks and fusion operations for dis-
cogenic back pain. In both diagnostic
groups, the authors detected high levels
of interleukin-6 and interleukin-8. The
authors hypothesized that the high level
of proinflammatory mediators may indi-
cate that a specific inflammatory form of
disk degeneration exists. This finding
may explain why some degenerated disks
cause low back pain while other morpho-
logically similar disks do not. These find-
ings and interpretations are intriguing
with regard to pain pathogenesis and de-
serve further attention and evaluation.
We acknowledge limitations of our
study. Inclusion of only patients who
were appropriate for surgery may have
caused a selection bias. However, because
discography is an invasive procedure
with a small but existing complication
rate (26), discography should be per-
formed only as a preoperative assessment
with a direct influence on treatment in
patients with a positive pain response
(26). It must be stressed that a presum-
ably normal disk (as an internal negative
control) was injected only in patients
with concordant pain with provocation.
The risk of performing surgery (ie, spinal
fusion) on the basis of false-positive pain
provocation results is substantially higher
than the rate of iatrogenic disk infection.
However, injection of a normal disk in pa-
tients without a concordant pain response
is not justifiable because it has no effect on
clinical decision making (ie, the patients
are excluded from surgery anyway because
of the negative pain response).
Other limitations are related to the
evaluation of discograms, as well as MR
images, and the applied imaging proto-
col. The fact that discograms were re-
viewed by the orthopedic spine surgeon
who performed discography may have
affected discographic grading. Since eval-
uation of MR images was performed by
two readers working in consensus, deter-
mination of interobserver variability in
grading the extent of endplate abnormal-
ities was not assessed. Nonuse of fat-
suppression techniques may have led to
underestimation of subtle endplate abnor-
malities. Furthermore, intravenous appli-
cation of a contrast agent was not part of
the imaging protocol. Because annular
tears might not be detected without appli-
cation of contrast material (5), this omis-
sion could have influenced our results.
In conclusion, our results indicate that
disk degeneration and the presence of a
high-signal-intensity zone may not cor-
respond directly to painful disk degener-
ation and should, therefore, not be used
to identify symptomatic intervertebral
disks. Conversely, moderate and severe
endplate type I and type II abnormalities
on MR images may indicate painful disk
derangement in patients with low back
pain.
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Volume 218
Number 2 Painful Lumbar Disk Derangement
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Page 8
  • Source
    • "La dégénérescence discale regroupe initialement la perte de hauteur discale, l'hyposignal T2 et le bombement discal. Si leur valeur prédictive négative de la dégénérescence discale est forte (98 %), signifiant que son absence rend peu probable la présence d'une douleur d'origine discale, leur VPP et leur spécificité restent modestes même en utilisant les grades 3 et 4 de la classification de Pfirrmann [27]. Hancock et al. rapportent des rapports de vraisemblance positifs mais peu élevés à partir du grade 3 de Pfirrmann (entre 2,8 et 5,7) et restant bien inférieur à celle du Modic 1 [58]. "
    [Show abstract] [Hide abstract] ABSTRACT: La lombalgie commune est un symptôme fréquent, pouvant aboutir à l’invalidité et à d’importantes répercussions socioprofessionnelles. Malgré les progrès techniques en imagerie, la cause précise de la douleur est souvent difficile à affirmer. Le vieillissement naturel du disque s’exprime sous forme de francs remaniements morphologiques en IRM chez des patients totalement asymptomatiques. La question de la valeur prédictive de ces remaniements se pose donc dans le cadre des lombalgies. À travers cette revue de littérature, nous avons souhaité établir un état des lieux des connaissances sur le sujet et, le cas échéant, en extraire les principales notions utiles à la bonne pratique de l’imagerie par IRM. Les segments antérieurs et postérieurs du rachis seront successivement traités en intégrant à chaque fois des rappels anatomiques, physiologiques puis sémiologiques. Dans un second temps, la valeur des signes retenus sera discutée.
    Full-text · Article · Mar 2014
  • Source
    • "The prevalence of VESC varies greatly among studies ranging from less than 1% in adolescents from the Danish general population [22] to 100% in selected patient populations [23]. Some studies observed an association between VESC and back pain [24] [25] [26] [27], whereas other studies did not observe any association [28] [29] [30] [31]. Studies correlating VESC on consecutive MRIs in patients with sciatica are limited, especially studies comparing surgery with conservative treatment for the development of VESC. "
    [Show abstract] [Hide abstract] ABSTRACT: BACKGROUND CONTEXT: Patients with sciatica frequently experience disabling back pain. One of the proposed causes for back pain is vertebral end-plate signal changes (VESC) as visualized by magnetic resonance imaging (MRI). PURPOSE: To report on VESC findings, changes of VESC findings over time, and the correlation between VESC and disabling back pain in patients with sciatica. STUDY DESIGN/SETTING: A randomized clinical trial with 1 year of follow-up. PATIENTS SAMPLE: Patients with 6 to 12 weeks of sciatica who participated in a multicenter, randomized clinical trial comparing an early surgery strategy with prolonged conservative care with surgery if needed. OUTCOME MEASURES: Patients were assessed by means of the 100-mm visual analog scale (VAS) for back pain (with 0 representing no pain and 100 the worst pain ever experienced) at baseline and 1 year. Disabling back pain was defined as a VAS score of at least 40 mm. METHODS: Patients underwent MRI both at baseline and after 1 year follow-up. Presence and change of VESC was correlated with disabling back pain using chi-square tests and logistic regression analysis. RESULTS: At baseline, 39% of patients had disabling back pain. Of the patients with VESC at baseline, 40% had disabling back pain compared with 38% of the patients with no VESC (p=.67). The prevalence of type 1 VESC increased from 1% at baseline to 35% 1 year later in the surgical group compared with an increase from 3% to 11% in the conservative group. The prevalence of type 2 VESC decreased from 40% to 29% in the surgical group while remaining almost stable in the conservative group at 41%. The prevalence of disabling back pain at 1 year was 12% in patients with no VESC at 1 year, 16% in patients with type 1 VESC, 11% in patients with type 2 VESC, and 3% in patients with both types 1 and 2 VESC (p=.36). Undergoing surgery was associated with increase in the extent of VESC (odds ratio [ OR], 8.6; 95% confidence interval [CI], 4.7-15.7; p <.001). Patients who showed an increase in the extent of VESC after 1 year did not significantly report more disabling back pain compared with patients who did not show any increase (OR, 1.2; 95% CI, 0.6-2.6; p=.61). CONCLUSION: In this study, undergoing surgery for sciatica was highly associated with the development of VESC after 1 year. However, in contrast with the intuitive feeling of spine specialists, those with and those without VESC reported disabling back pain in nearly the same proportion. Therefore, VESC does not seem to be responsible for disabling back pain in patients with sciatica.
    Full-text · Article · Nov 2013 · The spine journal: official journal of the North American Spine Society
  • Source
    • "Two recent publications suggest a possible relationship between bone marrow abnormalities revealed by MRI and discogenic pain [4] [28]. In these studies, moderate and severe types 1 and 2 endplate abnormalities were considered abnormal, and all the tested discs caused concordant pain on provocation [6]. Ohtori et al. reported that endplate abnormalities in patients with discogenic pain are related to inflammation and axonal growth into the abnormal bone marrow induced by cytokines, such as tumor necrosis factor-í µí»¼ [29]. "
    [Show abstract] [Hide abstract] ABSTRACT: Objective. Posterior dynamic stabilization is an effective alternative to fusion in the treatment of chronic instability and degenerative disc disease (DDD) of the lumbar spine. This study was undertaken to investigate the efficacy of dynamic stabilization in chronic degenerative disc disease with Modic types 1 and 2. Modic types 1 and 2 degeneration can be painful. Classic approach in such cases is spine fusion. We operated 88 DDD patients with Modic types 1 and 2 via posterior dynamic stabilization. Good results were obtained after 2 years of followup. Methods. A total of 88 DDD patients with Modic types 1 and 2 were selected for this study. The patients were included in the study between 2004 and 2010. All of them were examined with lumbar anteroposterior (AP) and lateral X-rays. Lordosis of the lumbar spine, segmental lordosis, and ratio of the height of the intervertebral disc spaces (IVSs) were measured preoperatively and at 3, 12, and 24 months after surgery. Magnetic resonance imaging (MRI) analysis was carried out, and according to the data obtained, the grade of disc degeneration was classified. The quality of life and pain scores were evaluated by visual analog scale (VAS) score and Oswestry Disability Index (ODI) preoperatively and at 3, 12, and 24 months after surgery. Appropriate statistical method was chosen. Results. The mean 3- and 12-month postoperative IVS ratio was significantly greater than that of the preoperative group (P < 0.001). However, the mean 1 and 2 postoperative IVS ratio was not significantly different (P > 0.05). Furthermore, the mean preoperative and 1 and 2 postoperative angles of lumbar lordosis and segmental lordosis were not significantly different (P > 0.05). The mean VAS score and ODI, 3, 12, and 24 months after surgery, decreased significantly, when compared with the preoperative scores in the groups (P = 0.000). Conclusion. Dynamic stabilization in chronic degenerative disc disease with Modic types 1 and 2 was effective.
    Full-text · Article · May 2013
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