eEdE-213
Imaging of degenerative scoliosis:
A review of current literature
S.Saipriya, J.Howard, C.J.Miranda, R. Siripurapu, A. Herwadkar
Department of Neuroradiology, Greater Manchester Neurosciences Centre,
Salford Royal NHS Foundation Trust, England UK
No disclosures
Definiton
 Primary degenerative scoliosis is a deformity developing in a
previously straight spine, caused by progressive
degeneration of the spine in middle age with progressive disc
and facet degeneration.
 This leads to generalised spondylosis and may result in
instability that leads to vertebral rotation, lateral listhesis or
spondylolisthesis.
 Scoliosis is defined as a lateral spinal curvature with a Cobb
angle of >10°.
Purpose (1)
 Degenerative scoliosis is a type of adult scoliosis and has
different etiologies.
 There is an increase in prevelance of degenerative scoliosis
in several countries with aging populations.
 A thorough radiological evaluation is imperative for
successful surgical management of adults with scoliosis.
 We aim to depict the various imaging modalities with their
relative utilities and also provide an update on the current
research on degenerative scoliosis.
Aebi, M. "The adult scoliosis." European Spine Journal 14.10 (2005): 925-948.
Ortiz, Orlando. Imaging of the Postoperative Spine, An Issue of Neuroimaging Clinics. Pages 69 - 74Vol.
24. No. 2. Elsevier Health Sciences, 2014.
Methods
 We reviewed the imaging findings of patients treated
with the intent of achieving spinal fusion presenting to
our tertiary neurosciences and spinal centre over the
past 7 years.
 A literature review on assessing spinal fusion was
carried out.
Background
 Several classification systems exist, there is no established
gold standard.
 Adult scoliosis has been broadly divided into three major
groups by Aebi M. et alPrimary or ‘de novo’ scoliosis
Idiopathic adolescent scoliosis with
progression in adult life
Type I
Type II
IIa :
IIb:
Type III
without secondary degenerative change
with secondary degenerative change
Secondary adult curves- due to leg
discrepancy, oblique pelvis, lumbosacral
anomaly, neuromuscular or congenital
trauma, iatrogenic or due to metabolic
transitional
scoliosis,
disease.
Grubb SA,
Lipscomb HJ, Coonrad RW (1988) Degenerative adult onset scoliosis. Spine 13:
241 – 245
Grubb SA, Lipscomb HJ (1992) Diagnostic findings in painful adult scoliosis. Spine 17(5): 518 – 527
Risk factors for curve progression
 Faster progression with curve greater than 30º.
 More than 30% rotation of apical vertebra.
 6mm or greater lateral listhesis
 L5-S1 disc degeneration
 Osteoporosis
Background
 Standard radiographs may provide us with clues regarding
the primary or secondary nature of the curves.
 Secondary degenerative scoliosis often tends to be
expressed more strongly, less osteoporotic and longer than
its primary counterpart.
 Schwab et al presented a classification system based purely
on the measurements of the endplate obliquity of L3 in the
frontal plane.
Type 1
Type 2
Type 3
lordosis > 55°, L3 obliquity < 15°
lordosis 35 – 55°, L3 obliquity 15 – 25°
lordosis < 35°, L3 obliquity > 25°
Schwab, F, el-Fegoun, AB, Gamez, L, Goodman, H, Farcy, JP (2005) A lumbar classification of scoliosis
in the adult patient: preliminary approach. Spine 30: pp. 1670-1673
Background
Primary degenerative adult scoliosis is most commonly seen in
the lumbar spine and results from segmental degeneration.
Asymmetric degeneration of the disc/ facet joints results in
asymmetric loading of the spinal segment resulting in deformity.
The presence of the deformity then
triggers further asymmetric loading
resulting in a vicious circle.
Progressive degeneration and deformity
often leads to central and foraminal
stenosis.
Aebi, M. "The adult scoliosis." European Spine Journal 14.10 (2005): 925948.
Clinical Manifestation
 Back pain- most frequent clinical problem.
 Can be either localised, radicular, or due to secondary muscular
fatigue.
 Claudication/ radicular pain
 Neurological deficit
 Increasing deformity
 Once the curve reaches a certain extent, progression
automatically follows.
 Cosmesis- although not as significant as in adolescent
scoliosis, with improvements in quality of life into older age,
this is becoming more important.
 Concomitant osteoporosis aggravates the clinical picture.
Ellwitz, J, and Gupta M. "Adult Degenerative Scoliosis." Spine Surgery Basics. Springer Berlin
Heidelberg, 2014. 247-258.
Diagnostic Work- up
Standard Radiographs
 Whole spine X Rays: Indispensable.
 Frontal and lateral planes with the centre of the skull and pelvis
included.
 Spot views of the lumbar spine
 Oblique radiographs to assess facet joints and neural foramina
 Functional views including side bending, flexion and extension
films.
Aebi, M. "The adult scoliosis." European Spine Journal 14.10.2005: 925-948.
Kim H, Kim HS, Moon ES, et al. Scoliosis imaging: What radiologists should know. RadioGraphics
2010 30:7, 1823-1842
Standard radiographs
•
•
•
•
Spinal curvature (Cobb angle)
Asymmetric disc degeneration
Lateral listhesis
Rotation of vertebrae
Plain radiographs depicting measurement of the cobb angle.
Maximal displacement of the apical vertebra is arrowed.
Standard Radiographs
 Placement of the head over the pelvis results in less energy
expenditure with movement, less stress in adjacent
segments and correlates with less symptoms.
 Sagittal balance is measured with a plumb line from the
posterior aspect of the superior end plate of C7 (other
authors use T3).
 If the line passes through the posterior aspect of the S1 endplate,
the alignment is neutral.
 Alternatively, some authors also describe a line from the
odontoid passing through the femoral heads but that may not
be feasible depending on the coverage of the radiograph.
Ellwitz, J, and Gupta M. "Adult Degenerative Scoliosis." Spine Surgery Basics. Springer Berlin
Heidelberg, 2014. 247-258.
Sagittal balance, C7-S1 plumb line
Negative balance
Balanced
Positive balance
Standard Radiographs
 Coronal balance is assessed by constructing a line that
bisects the sacrum and extends upwards to pass through the
centre of the C7 vertebral body and should normally bisect
the head.
Any deviation from this would be termed as right or left
decompensation.
 Other parameters that may be useful and have shown
correlation with pain scores are L3 or L4 tilt angle, listhesis,
thoracolumbar kyphosis and loss or lumbar lordosis.
 Cobb angle, plumb line, pelvic tilt and level of listhesis did not
show any correlation with pain scores.
 CT may be useful in some cases to assess complex 3
dimentional curves.
Ellwitz, J, and Gupta M. "Adult Degenerative Scoliosis." Spine Surgery Basics. Springer Berlin
Heidelberg, 2014. 247-258.
Schwab F, Smith V, Biserni M et al, Adult sco- liosis: a quantitative radiographic and clinical
analysis. Spine 2002. 27(4):387–392
Coronal and sagittal plumb lines
Vertical line from C7
passes through
mid S1
Vertical line from C7
Passes through
mid S1
Coronal imbalance
Right over balanced
Balanced
Left over balanced
Plain films – side bending views
Primary curve centered
at L4
Secondary curve at L23
Primary curve is
not corrected on
bending.
Secondary curve
is corrected.
Determines if curve
is fixed or otherwise.
Progressive worsening of scoliosis
2009
2011
2014
Comparison with previous radiographs shows increasing curvature; increasing lateral listhesis of L3
over L4 and increasing spondylosis with progressive degeneration at L2-3 space
Role of CT Imaging (1)
•
•
•
•
•
•
Spinal curvature
Asymmetric disc degeneration
Lateral listhesis
Tilt of vertebrae
Vertebral body rotation
Pelvic tilt
Role of CT imaging (2)
• Osseous elements of degeneration
• Osteophytic characterisation
• Bone density
• Pedicle size prior to surgery
• Instrumentation positioning
• Instrumentation failure
Role of CT imaging (3)
CT imaging demonstrates
Vacuum phenomenon
Multilevel disc degeneration
Rotation of vertebra
Exit foraminal narrowing
Role of CT imaging (4)
Facetal arthropathy
Protruding facets narrow the lateral recesses,compress the
traversing roots and contribute to canal stenosis.
CT 3D volume rendering
Allows for demonstration of Rotation of vertebral bodies
Asymmetric disc degeneration
Pelvic tilt
Exit foraminal narrowing
Magnetic Resonance Imaging
 Ideal for assessing neural compromise and disc
degeneration.
 If contraindicated, CT myelogram is a good alternative, and
simultanously produces images for 3D reformatting.
Asymmetric disc degeneration at
level of scoliosis
Many facets of degeneration
Thickening of ligamentum flavum
Facetal arthropathy
Interspinous bursal thickening
Lateral recess stenosis
Spinal stenosis
MR imaging depicting
• Narrowing of lower lumbar
central canal
• Degenerative disc bulges
• Facetal arthropathy
• Ligamentum flavum
thickening (arrow)
Coronal MR imaging
Demonstrates lateral listhesis
Exit foraminal narrowing on concave side (arrowed)
Stretched nerves on convex side
Treatment
 Must be tailored to individual patient.
 Medication, facet joint injections,epidural blocks, root blocks,
exercises and immobilization are non surgical options with
limited success.
 Surgical treatment options aim to achieve neural
decompression, correction and stabilisation of the deformity
and functional restoration.
Ellwitz, J, and Gupta M. "Adult Degenerative Scoliosis." Spine Surgery Basics. Springer Berlin
Heidelberg, 2014. 247-258.
Gupta M (2003) Degenerative scoliosis, options for sur- gical management. Orthop Clin North Am
34:269–279
Transpedicular instrumentation with disc cages
Pretreatment
Disc cages (arrows)
Correct positioning of screws
Pedicular screws should not breach the medial margin before traversing the vertebral body;
should be less than 2 mm beyond the anterior vertebral margin; without any lucency around
the tip; and should be intact. On follow up, its position should be unaltered.
Lumbo-pelvic fixation
This technically demanding procedure is performed
in patients with L5 S1 mobility, mainly to relieve
pain.
Jones, Clifford B., Debra L. Sietsema, and Martin F. Hoffmann. "Can lumbopelvic fixation salvage unstable
complex sacral fractures?." Clinical Orthopaedics and Related Research® 470.8 (2012): 2132-2141.
Fusion cages and bone graft to aid fusion
 Arrows denote fusion cages
 Speckled appearance of bone graft posteriorly
Fusion bony mass
…indicates succesful fusion.
Examples of failure of surgery for
degenerative scoliosis
Failure of fusion due to screw loosening
No bone in disc space at L4-5
Lucency along the screws
(loosening)
Mild anterior listhesis
Failure due to fracture below the prosthesis
Pretreatment
Long segment
fusion
Periprosthetic
fracture
Conclusion
 Adult degenerative scoliosis is an increasingly challenging
day to day radiological demand
 Imaging requires careful correlation between plain films, CT
and MR scans
 Plain films are useful in ascertaining balance, progress and
as a followup post treatment
 CT imaging is useful in demonstrating bony details, surgical
planning and in ascertaining prosthesis
 MR imaging will determine the effects on the neural
structures and for reviewing post treatment complications
End