Ten-year clinical and imaging follow-up of dural ectasia in adults with Marfan syndrome
BACKGROUND CONTEXT: Dural ectasia in the lumbosacral spine is a common feature of Marfan syndrome and is associated with low back pain and surgical complications, but its natural history is unknown. PURPOSE: To evaluate the natural history of dural ectasia in adults with Marfan syndrome by determining if, over time, symptoms associated with dural ectasia worsen, dural ectasia imaging findings worsen, or spondylolisthesis/spondylolysis develops or worsens. STUDY DESIGN: Prospective cohort study. PATIENT SAMPLE: For our prospective follow-up study, we enrolled 20 patients with Marfan syndrome and dural ectasia who, from 1998 through 1999, had undergone magnetic resonance imaging (MRI) and computed tomography (CT) of the lumbosacral spine and had completed the Oswestry Disability Index (ODI) questionnaire. Of the 20, five did not meet the inclusion criterion of a completed 2009 ODI questionnaire and were excluded. The remaining 15 patients (mean age, 49.6 years; mean follow-up, 10.5 years) formed our study group. OUTCOME MEASURES: The ODI, MRI-based qualitative and quantitative measurements, CT-based quantitative measurements. METHODS: We performed matched-pair analyses via Student t test and Wilcoxon signed-rank test of the ODI scores (15 pairs), dural volume of L5-S2 (eight pairs), dural sac ratio (DSR) of L4-S2 (nine pairs), development/progression of spondolysthesis/spondylolysis (11 pairs), and Fattori qualitative grading of dural ectasia size (10 pairs). Significance was set at p<.05. RESULTS: We found no statistical differences in the 1998/1999 and 2009 ODI scores (25.8 vs. 22.2 points), dural volume (70.4 vs. 73.9 cm(3)), or DSR (0.68, 0.78, 2.04, and 58.1 vs. 0.69, 0.83, 2.30, and 70.20). There was also no development or progression of spondylolisthesis/spondylolysis and no increase in dural ectasia size. CONCLUSIONS: During this 10-year period, the natural history of dural ectasia in adults with Marfan syndrome was not associated with a significant increase in ODI scores, dural ectasia size, or with the development/progression of spondylolisthesis or spondylolysis.
Ten-year clinical and imaging follow-up of dural ectasia in adults
with Marfan syndrome
Addisu Mesﬁn, MD
, Nicholas U. Ahn, MD
, John A. Carrino, MD, MPH
Paul D. Sponseller, MD, MBA
Department of Orthopaedic Surgery, The Johns Hopkins University, 601 N. Caroline St, Baltimore, MD 21287, USA
Department of Orthopaedic Surgery, Case Western Reserve University School of Medicine, 10900 Euclid Ave, Cleveland, OH 44106, USA
University Hospitals of Cleveland, Case Medical Center, 11100 Euclid Ave, Cleveland, OH 44106, USA
Department of Radiology, The Johns Hopkins University, 601 N. Caroline St, Baltimore, MD 21287, USA
Received 30 August 2011; revised 29 June 2012; accepted 13 October 2012
Abstract BACKGROUND CONTEXT: Dural ectasia in the lumbosacral spine is a common feature of
Marfan syndrome and is associated with low back pain and surgical complications, but its natural
history is unknown.
PURPOSE: To evaluate the natural history of dural ectasia in adults with Marfan syndrome by de-
termining if, over time, symptoms associated with dural ectasia worsen, dural ectasia imaging ﬁnd-
ings worsen, or spondylolisthesis/spondylolysis develops or worsens.
STUDY DESIGN: Prospective cohort study.
PATIENT SAMPLE: For our prospective follow-up study, we enrolled 20 patients with Marfan
syndrome and dural ectasia who, from 1998 through 1999, had undergone magnetic resonance
imaging (MRI) and computed tomography (CT) of the lumbosacral spine and had completed the
Oswestry Disability Index (ODI) questionnaire. Of the 20, ﬁve did not meet the inclusion criterion
of a completed 2009 ODI questionnaire and were excluded. The remaining 15 patients (mean age,
49.6 years; mean follow-up, 10.5 years) formed our study group.
OUTCOME MEASURES: The ODI, MRI-based qualitative and quantitative measurements,
CT-based quantitative measurements.
METHODS: We performed matched-pair analyses via Student t test and Wilcoxon signed-rank
test of the ODI scores (15 pairs), dural volume of L5–S2 (eight pairs), dural sac ratio (DSR) of
L4–S2 (nine pairs), development/progression of spondolysthesis/spondylolysis (11 pairs), and
Fattori qualitative grading of dural ectasia size (10 pairs). Signiﬁcance was set at p!.05.
RESULTS: We found no statistical differences in the 1998/1999 and 2009 ODI scores (25.8 vs.
22.2 points), dural volume (70.4 vs. 73.9 cm
), or DSR (0.68, 0.78, 2.04, and 58.1 vs. 0.69,
0.83, 2.30, and 70.20). There was also no development or progression of spondylolisthesis/spondy-
lolysis and no increase in dural ectasia size.
CONCLUSIONS: During this 10-year period, the natural history of dural ectasia in adults with
Marfan syndrome was not associated with a signiﬁcant increase in ODI scores, dural ectasia size,
FDA device/drug status: Not applicable.
Author disclosures: AM: Nothing to disclose. NUA: Grants: Stryker
(C). JA C: Consulting: Quality Medical Metrics (B), Medtronic (B), Tissue-
Gene (B); Scientiﬁc Advisory Board: Siemens Medical Systems
(Amount not disclosed), Carestream Healthcare (Amount not disclosed),
GE Pain Management (Amount not disclosed), Merge Healthcare (Stock
ownership); Research Support (Investigator Salary): Carestream (B, Paid
directly to institution/employer), MedImmune (B, Paid directly to institu-
tion/employer); Grants: Siemens Medical Systems (E, Paid directly to
institution/employer), Integra (D, Paid directly to institution/employer),
Toshiba Medical Systems (D, Paid directly to institution/employer). PDS:
Device or Biologic Distributorship (Physician-Owned Distributorship):
DePuy Spine (C); Royalties: Globus Spine (B); Consulting: DePuy Spine
(B); Speaking/Teaching Arrangements: DePuy Spine (Amount not dis-
closed); Trips/Travel: DePuy Spine (A); Board of Directors: Scoliosis Re-
search Society (None); Research Support (Staff/Materials): DePuy Spine
(C); Grants: DePuy Spine (C); Fellowship Support: OREF (E).
The disclosure key can be found on the Table of Contents and at www.
* Corresponding author. (c/o Elaine P. Henze, BJ, ELS, Medical Editor
and Director). Department of Orthopaedic Surgery, The Johns Hopkins
University/Johns Hopkins Bayview Medical Center, 4940 Eastern Ave.,
#A665, Baltimore, MD 21224-2780, USA. Tel.: (410) 550-5400; fax:
E-mail address: firstname.lastname@example.org (P.D. Sponseller)
1529-9430/$ - see front matter Ó 2013 Elsevier Inc. All rights reserved.
The Spine Journal 13 (2013) 62–67
or with the development/progression of spondylolisthesis or spondylolysis. Ó 2013 Elsevier Inc.
All rights reserved.
Keywords: Dural ectasia; Marfan syndrome; Spondylolisthesis; Low back pain; Oswestry Disability Index
Dural ectasia in the lumbosacral spine is a common fea-
ture of Marfan syndrome. Marfan syndrome, an autosomal-
dominant connective tissue disorder that affects one per
5,000 people, is caused by mutations in the genes encoding
ﬁbrillin-1 [1,2]. Deﬁciencies in ﬁbrillin-1 have been shown
to increase the levels of transforming growth factor
b (TGF-b). Increased levels of TGF-b are thought to result
in the phenotypic manifestations of Marfan syndrome such
as aortic root dilatation [2,3]. Marfan syndrome is diag-
nosed via the modiﬁed Ghent criteria , and dural ectasia
is one of the systemic features used to diagnose Marfan
syndrome and was formerly a major criterion for diagnosis
[5,6]. Dural ectasia is deﬁned as ballooning or widening of
the dural sac and nerve root sleeves. In Marfan syndrome,
dural ectasia is commonly found in the lumbosacra l spine
and is associa ted with the thinning of adjacent osseous
structures (vertebrae, pedicles, laminas). Severe forms of
dural ectasia can manifest as anterior meningoceles. Symp-
toms associated with dural ectasia include back pain, head-
aches, abdominal pain, and leg pain [7,8]. Low back pain is
the most common symptom and is found in up to 90% of
patients . Imaging modalities, such as computed tomog-
raphy (CT) and magnetic resonance imaging (MRI ), are
used to diagnose it [7–9].
Although dural ectasia is found in 63% to 92% of pa-
tients with Marfan syndrome [6,10], the natural history of
dural ectasia in Marfan syndrome is relatively unknown
[9,11]. In addition, spondylolisthesis is found in 6% of pa-
tients with Marfan syndrome; it is not known if dural ecta-
sia can lead to the progression or development of
spondylolisthesis/spondylolysis over time . The goal
of our study was to evaluate the natural history of dural ec-
tasia in adults with Marfan syndrome by determining if,
over time, symptoms associated with dural ectasia worsen,
dural ectasia imaging ﬁndings worsen, or spondylolisthesis
or spondylolysis develops or worsens.
This study was approved by our institutional review
Study design and patients
In this prospective cohort investigation, we began by re-
viewing a previously studied group of patients to identify
those with dural ectasia and Marfan syndrome who, from
1998 through 1999, under went an MRI and CT of the
lumbosacral spine and who completed the Oswestry Dis-
ability Index (ODI) questionnaire. These patients with Mar-
fan syndrome and dural ectasia from 1998 through 1999
volunteered to participate in the origina l study and were en-
rolled via the Marfan Center at our institution and via vol-
unteer recruiting through the National Marfan Foundation.
They represent the typical Marfan patient population. For
our present study, all 20 identiﬁed patients from the original
study were contacted. However, at the end of the study pe-
riod (2009), ﬁve of the 20 had not met the inclusion crite-
rion of a completed 2009 ODI questionnaire and were
excluded. The remaining 15 patients formed our study
group. The mean age of the eight women and seven men
was 49.6 years (range, 41.1–61.2 years), and the mean
follow-up was 10.5 years (range, 9.8–11.1 years). For those
15 patients, we compared the 1998/1999 and 2009 ODI
scores (15 pairs), dural volume of L5–S2 (eight pairs), du-
ral sac ratio (DSR) of L4–S2 (nine pairs), development/pro-
gression of spondylolisthesis/spondylolysis (11 pairs), and
Fattori qualitative grading (10 pairs) (Table 1).
The ODI was our primary outcome measure for deter-
mining the natural history of low back pain associated with
dural ectasia . The ODI is scored from 0 to 100 points,
and a higher ODI score is associated with higher disability
and low back pain.
Magnetic resonance imaging of the lumbosacral spine
was used to assess the volume of dural ectasia. The 1998/
1999 images had been obtained via a previously described
protocol . For the 2009 imaging, a 3T MRI system
(MAGNETOM Trio; Siemens Medical Systems, Erlangen,
Germany) was used to obtain noncontrast images of the
lumbosacral spine, and two-dimensional and isotropic
three-dimensional pulse sequences (T1 magnetization-
prepared rapid acquisition of gradient-echo imaging, T2
sampling perfectio n with application-optimized contrasts
using different ﬂip angle evolutions) were acquired. In
2009, a 64-slice multidetector CT was also used to image
the lumbosacral spine to assess the presence of spondylolis-
thesis/spondylolysis and to evaluate osseous anatomy.
Postprocessing was performed on a commercially avail-
able AW workstation (Advantage Windows 3.1; General
Electric Healthcare, Piscatawa, NJ, USA). One operator
63A. Mesﬁn et al. / The Spine Journal 13 (2013) 62–67
trained in the use of the workstation performed all the vol-
umetric measurements. The Volume Viewer program from
the AW workstation was used to measure the L5 –S2 dural
volumes. On the T2-weighted axial MRI scans, the inferior
end plate of L5 was identiﬁed, and the volume below the
inferior end plate of L5–S2 was measured, as described pre-
viously . Using the AW workstation, the dural sac from
L5 to S2 was segmented as a separate series. Volume mea-
surements of the initial 1998/1999 and 2009 MRI scans
The DSR was calculated for L4–S2 according to the
method of Oosterhof et al. : the dural sac diameter is
divided by the vertebral body diameter at each level from
L4 to S2 (Fig. 1). The midline image, as conﬁrmed on
the axial series, of the sagittal T2-weighted series was used.
The widths of the middle of each vertebral body (deter-
mined by measuring from the superior to inferior end plate
and dividing by two) and of each corresponding dural sac
were measured. The DSR measurements for the initial
1998/1999 and 2009 MRI scans were made.
Evaluation of spondylolisthesis/spondylolysis
Computed tom ography scans of the lumbosacral spine
without contrast were obtained for the evaluation of spon-
dylolisthesis/spondylo lysis and osseous anatomy. The de-
gree of slip was evaluated via the Meyerding criteria .
Qualitative measurements of dural ectasia
The degree of dural abnormality was measured on the
T2-weighted sagittal MRI scans (Fig. 2) according to the
MRI-based dural ectasia grading system of Fattori et al.
: 0, normal; 1, mild dural ectasia (bulging of the dural
sac and lack of epidural fat at the level of the posterior wall
of one vertebral body, the presence of small radicular cysts,
or both features); 2, moderate dural ectasia (bulging of the
dural sac and lack of epidural fat at the level of the poste-
rior wall of two or more vertebral bodies and the presence
of large radicular cysts); and 3, severe dural ectasia (the
presence of anterior sacral meningocele).
A paired Student t test was used to compare the 1998/1999
dural ectasia volume measurements, DSR, and ODI scores of
each patient with those for 2009. Signiﬁcance was set at
ap!.05. A Wilcoxon signed-rank test was used to perform
a matched-pair analysis of the DSR and dural ectasia volume
measurements from 1998/1999 and 2009. Stata statistical
software version 10.0 (StataCorp, College Station, TX,
USA) was used for statistical calculations. A post hoc power
analysis showed that to ﬁnd a difference of 15 points in the
ODI score with a power greater than 80%, a total number
of 15 patients would be needed and that seven patients would
be sufﬁcient for a power greater than 80% if a dural volume
difference of 30 mL was used as a cutoff for indicating an
increase in the dural ectasia size.
No signiﬁcant differences (p!.05) were noted in the
ODI scores, dural ectasia volume, or DSR between the
1998/1999 and 2009 values.
The average OD I scores for the 15 patients in 1998/1999
and 2009 were 25.8 points (range, 0–6.67 points) and 22.2
points (range, 0–62.2 points), respectively. The difference
was not sta tistically signiﬁcant (p5.46).
No. of patients evaluated
(matched cohort from
original 1998/1999 study
to the present study) (%)
Evaluation of symptoms associated with
dural ectasia: ODI
Quantitative evaluation of dural ectasia:
dural volume measurement
Quantitative evaluation of dural ectasia:
Evaluation of spondylolisthesis/
spondylolysis progression or development
Qualitative evaluation of dural ectasia
ODI, Oswestry Disability Index; DSR, dural sac ratio.
Dural ectasia in Marfan’s syndrome can be a source of
pain and neurologic issues. The authors aimed to assess
the likel ihood of clinical and radiographic progression of
this ﬁnding in adults with the syndrome.
In the current study, no clinical or radiographic progres-
sion was noted in the adult study cohort.
Although the numbers were small and broad conclusions
should be drawn with caution, it appears that dural ecta-
sia in adults with Marfan’s syndrome is very unlikely to
be a new or progressive ﬁnding. This study suggests that
attributing new onset pain or disability to isolated dural
ectasia in adult patients with Marfan’s syndrome should
be considered with appropriate skept icism.
64 A. Mesﬁn et al. / The Spine Journal 13 (2013) 62–67
Of the 15 patients, four did not have repeat MRI scans of
the lumbosacral spine for the following reasons (one each):
refusal secondary to claustrophobia, refusal secondary to
severe low back pain associated with lying down, prohibi-
tive geographical distance, and death. Of the 11 patients
with repeat MRI scans (Fig. 3), the 1998/1999 scans of
eight were accessible for measurements via the volume
Workstation viewer program. Matched-pair analysis of the
mean dural volume measurements for the eight patients
with accessible 1998/1999 and 2009 MRI scans showed
no statistically signiﬁcant differences: 70.4 cm
) and 73.9 cm
(range, 16.7–140.3 cm
respectively, on paired Student t test (p5.55) or Wilcoxon
signed-rank test (p5.89).
Of the 1 1 patients with repeat MRI scans of the lumbo-
sacral spine, matched-pair analysis was available for nine.
The mean DSR values from 1998/ 1999 and 2009 were
not signiﬁcantly different at any level (L4–S2) by Student
t test (p!.05) or Wilcoxon signed-rank test (Table 2 ).
Evaluation of spondylolisthesis/spondylolysis
Of the 15 patients, 11 had 1998/1999 and 2009 lumbo-
sacral CT scans available for matched-pair analysis for
the development of spondylolisthesis and the presence of
spondylolysis. Of the 11, only two had spondylolisthesis
in 1998/1999; both instances were at the L5–S1 level and
were Grade 2 according to the Meyerding criteria .
Comparison with the 2009 scans showed no progression.
There was no evidence of spondylolysis. No patient devel-
oped spondylolisthesis/spondylolysis over the study period.
Of the 10 matched pairs that underwe nt Fattori qualita-
tive staging of dural ectasia of the lumbosacral spine, two
had Fattori Grade 1 (mild) dural ectasia, ﬁve had Fattori
Grade 2 (moderate) dural ectasia, and three had Fattori
Fig. 2. The grading system of Fattori et al.  for dural ectasia: (Left) Grade 1, mild; (Middle) Grade 2, moderate; and (Right) Grade 3, severe.
Fig. 1. Dural sac ratio calculation. Arrow A, dural sac diameter; Arrow B,
vertebral body diameter. H, head; F, foot.
65A. Mesﬁn et al. / The Spine Journal 13 (2013) 62–67
Grade 3 (severe) dural ectasia. None of the matched pairs
showed a change in Fattori grade over the 10-year study
We found that, at an average of 10.5 year s of follow-up
for our patients with Marfan syndrome and dural ectasia,
there was no signiﬁcant increas e in dural ectasia severity
based on lumbosacral MRI measurements and Fattori qual-
itative evaluations, no sign iﬁcant increase in low back pain
or sign iﬁcant change in the ODI scores, and no worsening
of existing spondylolisthesis, no development of new spon-
dylolisthesis, and no development of spondylolysis over
Dural ectasia is thought to be the result of increased
pressure in the caudal portion of the spine, causing ectasia
secondary to a weakened connective tissue . Animal
studies of dural ectasia have shown increased levels of
TGF-b in the dura , which correlates with the current
understanding of Marfan syndrome as a deﬁciency in
ﬁbrillin-1 resulting in an increased expression of TGF-b
and ensuing phenotypic manifestations .
Dural ectasia can result in erosion of the osseous struc-
tures of the lumbosacral spine . As the dura balloons, it
is thought to gradually cause erosion of the surrounding
bone . Mean values for pedicle width and lamina thick-
ness in the lumbosacral spine affected by dural ectasia have
been reported as signiﬁcantly less than those for normal
controls . The combination of thin pedicles, thin lami-
nae, and weak dural connective tissue can make opera tive
ﬁxation of the Marfan spine challenging: an 8% dural tear
rate and an 8% lamina fracture rate have been reported
when correcting the Marfan spine .
Low back pain is a common symptom associated with
dural ectasia [7,9]. Our results indicate that low back pain
did not worsen over the period observed based on the
ODI scores. Only two of the original cohort underwent
lumbar spine surgery: one had surgery for a disc herniation
and one had surgery to treat the dural ectasia at another in-
stitution. Theories about the cause of the symptoms associ-
ated with dural ectasia include direct pressure on the
periosteum, erosion of the lumbosacral elements, traction
of neural roots, direct pressure by anterior meningocele
on abdominal organs, and thinning of the sacrum that re-
sults in microfractures [8,19–22]. However, one study has
also reported that 41% of patients with dural ectasia had
no back pain . In our study, less than half of the patients
had ODI scores below 10, which indicates minimal low
back pain and minimal changes in quality of life secondary
to the low back pain. Foran et al.  suggested that the clas-
sic picture of dural ectasia symptoms was ‘‘low/very low
(sacral) back pain (ache), headache, proximal leg pain
(ache) with components of weakness and numbness above
and below the knee, genital/rectal pain, and disturbance of
functional abilities.’’ Correlation of symptoms with dural
ectasia requires additional investigation.
Based on our quantitative and qualitative evaluations,
dural ectasia size does not appear to increase over time:
matched-pair analysis showed no signiﬁcant difference in
the dural volume or DSR, and the Fattori grade did not
show a change or increase. Indeed, our data indicated that
dural ectasia size had plateaued. In one study, dural ectasia
was noted in 40% of children with Marfan syndrome at
a median age of 12.6 years; their DSRs at L5 and S1 were
noted to be signiﬁcantly higher than those in controls .
In our patient age range (40–60 years old in 2009), the du-
ral ectasia size had not increased, supporting the concept
that dural ectasia size may peak during adolescence or early
adulthood and then plateau. Future studies examining when
the growth of dural ectasia peaks would be useful.
The rate of spondylolisthesis at L5–L1 in the general
population has been reported as 3% , whereas that in
patients with Marfan syndrome is 6%  . Spondylolisthe-
sis in the Marfan spine usually involves a high-grade slip
. The higher degree of slip seen in patients with Marfan
syndrome may be the result of the underlying connective
Matched-pair analysis of average DSR measurements at L4–S2 for nine
t test (p)
signed-rank test (p)1998/1999 2009
L4 0.68 0.69 .63 .953
L5 0.78 0.83 .06 .066
S1 2.04 2.29 .53 .515
S2 58.1 70.2 .24 .441
DSR, dural sac ratio.
Fig. 3. This 48-year-old man had a Fattori 2 (moderate) dural ectasia. The
T2-weighted sagittal magnetic resonance imaging scans of the lumbosacral
spine in (Left) 1998 and (Right) 2009 show a similar appearance and vol-
ume of dural ectasia. From 1998 to 2009, his Oswestry Disability Index
(ODI) did not change, and the dural volume (V) for L5–S2 showed a non-
66 A. Mesﬁn et al. / The Spine Journal 13 (2013) 62–67
tissue disorder leading to changes in the ligament and disc
properties . In our two patients (Grade 2 slip), the ODI
scores were low and did not signiﬁcantly change over the
span of our study. Dural ectasia has been reported to com-
plicate spondylolisthesis correction and decompression be-
cause of the associated large dural tears and thin osseous
None of our patients had spondylolysis initially or devel-
oped it during the course of the study. This lack of spondy-
lolysis in patients with Marfan syndrome has been observed
There were a few limitations to this study. First, the sam-
ple size was small, and the number of values for com-
parison varied. However, to our knowledge, this study
represents the longe st average follow-up (10.5 years) to
date for patients with dural ectasia and Marfan syndrome.
Second, the dural volume measurements were performed
by only one observer; therefore, interobserver reliability
was not tested. However, the technique used to perform
the measurements has been validated previously, and one
observer performing the measurements resulted in unifor-
mity [9,17]. Third, demographic information about the vol-
unteers, such as height, weight, and body mass index was
not recorded. However, this information was also not re-
corded during the original study from 1998 through 1999.
It would have been useful to have this demographic infor-
mation available to evaluate if there was a correlation be-
tween ODI scor e and the patients’ body mass index.
In conclusion, we found that, for the decade studied, du-
ral ectasia was not associated with worsening low back
pain, increasing size, developing or worsening spondylolis-
thesis, or developing spondylolysis. Future studies with
larger patient populations and longer follow-ups are war-
ranted. In addition, a prospective study of young adults
and adolescents with dural ectasia and Marfan syndrome
would help determine when the peak dural ectasia volume
 Dietz HC, Cutting GR, Pyeritz RE, et al. Marfan syndrome caused by
a recurrent de novo missense mutation in the ﬁbrillin gene. Nature
 Brooke BS, Habashi JP, Judge DP, et al. Angiotensin II blockade and
aortic-root dilation in Marfan’s syndrome. N Engl J Med 2008;358:
 Neptune ER, Frischmeyer PA, Arking DE, et al. Dysregulation of
TGF-beta activation contributes to pathogenesis in Marfan syndrome.
Nat Genet 2003;33:407–11.
 Loeys BL, Dietz HC, Braverman AC, et al. The revised Ghent nosol-
ogy for the Marfan syndrome. J Med Genet 2010;47:476–85.
 De Paepe A, Devereux RB, Dietz HC, et al. Revised diagnostic cri-
teria for the Marfan syndrome. Am J Med Genet 1996;62:417–26.
 Pyeritz RE, Fishman EK, Bernhardt BA, Siegelman SS. Dural ectasia
is a common feature of the Marfan syndrome. Am J Hum Genet
 Ahn NU, Sponseller PD, Ahn UM, et al. Dural ectasia is associated
with back pain in Marfan syndrome. Spine (Phila Pa 1976) 2000;25:
 Foran JRH, Pyeritz RE, Dietz HC, Sponseller PD. Characterization of
the symptoms associated with dural ectasia in the Marfan patient. Am
J Med Genet 2005;134A:58–65.
 Ahn NU, Sponseller PD, Ahn UM, et al. Dural ectasia in the Marfan
syndrome: MR and CT ﬁndings and criteria. Genet Med 2000;2:
 Fattori R, Nienaber CA, Descovich B, et al. Importance of dural ec-
tasia in phenotypic assessment of Marfan’s syndrome. Lancet
 Jones KB, Sponseller PD, Erkula G, et al. Symposium on the muscu-
loskeletal aspects of Marfan syndrome: meeting report and state of
the science. J Orthop Res 2007;25:413–22.
 Sponseller PD, Hobbs W, Riley LH III, Pyeritz RE. The thoracolumbar
spine in Marfan syndrome. J Bone Joint Surg Am 1995;77:867–76.
 Roland M, Fairbank J. The Roland-Morris Disability Questionnaire
and the Oswestry Disability Questionnaire. Spine (Phila Pa 1976)
 Oosterhof T, Groenink M, Hulsmans FJ, et al. Quantitative assess-
ment of dural ectasia as a marker for Marfan syndrome. Radiology
 Meyerding HW. Spondylolisthesis. Surg Gynecol Obstet 1932;54:
 Jones KB, Myers L, Judge DP, et al. Toward an understanding of du-
ral ectasia: a light microscopy study in a murine model of Marfan
syndrome. Spine (Phila Pa 1976) 2005;30:291–3.
 Sponseller PD, Ahn NU, Ahn UM, et al. Osseous anatomy of
the lumbosacral spine in Marfan syndrome. Spine (Phila Pa
 Jones KB, Erkula G, Sponseller PD, Dormans JP. Spine deformity
correction in Marfan syndrome. Spine (Phila Pa 1976) 2002;27:
 Duncan RW, Esses S. Marfan syndrome with back pain secondary to
pedicular attenuation. A case report. Spine (Phila Pa 1976) 1995;20:
 Nallamshetty L, Ahn NU, Ahn UM, et al. Dural ectasia and back
pain: review of the literature and case report. J Spinal Disord Tech
 Smith MD. Large sacral dural defect in Marfan syndrome. A case
report. J Bone Joint Surg Am 1993;75:1067–70.
 Stern WE. Dural ectasia and the Marfan syndrome. J Neurosurg
 Knirsch W, Kurtz C, Haffner N, et al. Dural ectasia in children with
Marfan syndrome: a prospective, multicenter, patient-control study.
Am J Med Genet A 2006;140:775–81.
 Fredrickson BE, Baker D, McHolick WJ, et al. The natural history of
spondylolysis and spondylolisthesis. J Bone Joint Surg Am 1984;66:
67A. Mesﬁn et al. / The Spine Journal 13 (2013) 62–67