Download Annotations Part II Vertebral Fracture Initiative Slide 1 Slide 3

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Part II Vertebral Fracture Initiative
©International Osteoporosis Foundation
With the kind collaboration of the European Society for
Musculoskeletal Radiology
March 2011
Slide 1
• Vertebral fractures are powerful predictors of future spine and hip
fractures, so accurate diagnosis and clear, unambiguous reporting are
essential.
• There is considerable evidence that vertebral fractures are underreported, and when present appropriate intervention may not occur.
• The purpose of this document is to raise awareness of the relevance
and importance of identification of vertebral fractures.
Slide 3
• There is evidence that vertebral fractures are under-reported, and
when present appropriate intervention may not occur. Improvement
in the diagnosis and management of osteoporosis will reduce future
fracture risk and suffering.
Relevant references:
- Gehlbach SH et al. (2000) Recognition of vertebral fracture in a
clinical setting. Osteoporos Int 11: 577-82
- Delmas PD et al. (2005) Underdiagnosis of vertebral fractures is a
worldwide problem: the IMPACT study J Bone Miner Res 20(4): 557
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Technical considerations for
radiographs
Slide 4
Slide 5
• Radiographs are still the most common imaging technique used for
vertebral fractures identification, but need to be of good technical
quality to avoid artefactual appearances which might mimic vertebral
fractures.
• This particularly applies to lateral views in which the divergent X-ray
beam, poor positioning or scoliosis may result in biconcave endplates
which must not erroneously be interpreted as vertebral fractures.
• In the breath-hold technique in the thoracic spine, rib margins may
obscure vertebral endplates. This may be overcome by the breathing,
or long exposure, technique which results in movement blurring of
the overlying ribs and lung parenchyma, so that vertebral bodies are
more clearly visualized. This technique may be difficult in elderly
patients (have to remain still for longer exposure time [2-4 seconds]),
and is not possible on X-ray equipment with automatic exposure time.
• For lateral spinal radiographs it is essential to ensure that the spine is
parallel to the X-ray table/film, by careful positioning of the patient,
and that the X-ray beam is appropriately centred (T7 for thoracic
spine; L3 for lumbar spine).
• This avoids the `bean can’ effect when the X-ray beam is not parallel
to the vertebral endplates which therefore appear biconcave and may
simulate vertebral fractures.
• In severe scoliosis it may be impossible to position the patient to avoid
apparent biconcavity of endplates.
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Slide 6, 7
• X-ray exposure must be appropriate so as not to under- or overexpose area being radiographed, as this may cause apparent
increased (osteosclerosis) or decreased (osteopenia) bone density.
• Patient size also effects X-ray penetration, causing bones to
artefactually appear increased in density in large and over-weight
patients, and falsely osteopenic in thin patients.
Slide 8
• Typical patient effective radiation doses: from spine, chest and other
radiographic examinations. The average effective doses from the
average annual natural background radiation and from a return
transatlantic flight are given for comparison.
Relevant references:
- Wall BF, Hart D (1997) Revised radiation doses for typical X-ray
examinations, report on a recent review of doses to patients from
medical X-ray examinations in the UK by NRPB. Br J Radiol 70(833):
437-9
- Hart D, Wall BF (2002) National Radiation Protection Board, Oxon.
- Blake G, Naeem M, Boutros M (2006) Comparison of effective dose
to children and adults from dual X-ray absorptiometry examinations.
Bone 38: 935-42
- United Nations Scientific Committee on the Effects of Atomic
Radiation. UNSCEAR 2000 Report to the General Assembly, with
scientific annexes. Volume I. Vienna, Austria, UNSCEAR
- Saez Vergara J et al. (2004) In-flight measured and predicted
ambient dose equivalent and latitude differences on effective dose
estimates. Radiat Prot Dosim 110: 363-370
Vertebral fracture shape recognition
Slide 9
• A key to visual identification of fractures and non-fracture deformities
is an in depth knowledge of the normal range and variation in
vertebral shape and appearance of normal endplates.
Slide 10
• Normal vertebrae are usually rectangular in shape with well define
(crisp) cortical endplates.
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Slide 11
• A standardized approach to the diagnosis of vertebral fractures is
desirable for accuracy and consistency. The semi-quantitative (SQ)
method of Genant et al seems to be the most suitable for clinical
applications, since the severity of all vertebral fractures is assessed in a
semi-quantitative fashion.
• The severity of a fracture is assessed solely by visual determination of
the extent of vertebral height reduction and morphological change,
and vertebral fractures are differentiated from other, non-fracture
deformities.
Relevant reference:
- Genant HK et al. (1993) Vertebral fracture assessment using a semiquantitative technique. J Bone Miner Res 8(9): 1137-48
Slide 12
• Using the Genant et al. SQ method, the approximate degree of height
reduction determines the assignment of grades to each vertebra.
• Unlike other approaches, the type of deformity (wedge, biconcavity or
compression [crush]) is no longer linked to the grading of a fracture in
this approach.
Semi-quantitative visual grading
examples
Slide 13
• Using the Genant et al SQ method, thoracic and lumbar vertebrae are
graded on visual inspection of lateral spinal images and generally
without direct vertebral measurement as:
• normal (grade 0);
• mildly deformed (grade 1: approximately 20-25% reduction in
anterior, middle, and/or posterior height and 10-20% reduction of
the projected vertebral area);
• moderately deformed (grade 2: approximately 25-40% reduction in
anterior, middle, and/or posterior height and 20-40% reduction of
the projected vertebral area);
• severely deformed (grade 3: approximately 40% or greater reduction
in anterior, middle, and/or posterior height and in the projected
vertebral area).
Slide 14
• Mildly deformed grade 1: approximately 20-25% reduction in
anterior, middle, and/or posterior height and 10-20% reduction of
the projected vertebral area. There is less consistency, and more
debate, in diagnosis of mild (grade 1) fractures, than with moderate
(grade 2) and severe (grade 3) fractures.
Relevant references:
- Genant HK et al. (1996) Comparison of semiquantitative visual
and quantitative morphometric assessment of prevalent and incident
vertebral fractures in osteoporosis The Study of Osteoporotic
Fractures Research Group J Bone Miner Res 11(7): 984-96
- Ferrar L et al. (2008) J Bone Miner Res 23(3): 417-24
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Slide 15
• Mildly deformed grade 1: approximately 20-25% reduction in
anterior, middle, and/or posterior height and 10-20% reduction of
the projected vertebral area.
• Severely deformed grade 3: approximately 40% or greater reduction
in anterior, middle, and/or posterior height and in the projected
vertebral area.
Slide 16
• Subtle incident fractures are generally easily identified by comparison
with previous radiographs.
Slide 17
• Grade 2 (moderate) incident fractures are easily identified by
comparison with previous radiographs.
Slide 18
• Grade 2 (moderate) and grade 3 (severe) incident fractures are easily
identified by comparison with previous radiographs.
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Radiographic osteopenia or
osteoporosis and differential diagnosis
Slide 19
• There are numerous etiologies which result in vertebral fractures or
deformities.
Slide 20
• Features may depend on radiographic technique. If there is spinal
osteopenia, thinned cortex and/or prominent vertical trabecular
striations (due to loss of transverse trabeculae) in the vertebrae, these
features are strongly suggestive of osteoporosis.
• It would be appropriated in the report to suggest central DXA bone
densitometry (hip and lumbar spine) should be performed to confirm
or refute whether the patient has osteoporosis.
Slide 21
• Features may depend on radiographic technique. If there is
osteopenia, thinned cortex and/or prominent vertical trabecular
striations, these features strongly suggestive of osteoporosis, one
must be suspicious of osteoporosis and therefore suggest central
DXA.
Relevant reference:
- Quek ST, Peh WC (2002) Radiology of osteoporosis. Semin
Musculoskelet Radiol 6(3): 197-206
Slide 22
• Postmenopausal bone loss following the early years (maximum bone
loss occurs during first four years after the menopause) can lead to
fractures in later life, particularly in sites of the skeleton rich in
trabecular bone (spine, wrist, hip).
• Vertebral fractures are the most common of osteoporotic fractures
and tend to occur at an earlier age than other such fractures.
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Slide 23
• In osteomalacia there is reduced mineralisation of osteoid (qualitative
abnormality of bone) and the bone is soft and bends; this results in
increased smooth curvature of the endplates (‘cod fish’ vertebrae).
Slide 24
• Large doses, or long-term therapy with glucocorticoids is a secondary
cause of osteoporosis and tends to particularly affect sites of the
skeleton rich in trabecular bone (spine, wrist and hip).
• In vertebral fractures marginal condensation of the endplates from
impaction, and exuberant callus formation, may be seen in extreme
cases.
Slide 25
• If there is rapid onset and/or extensive generalised osteopenia,
particularly if there is evidence of localised lucent areas in the
skeleton, consider multiple myeloma, in which there will be a
monoclonal paraprotein in serum or urine.
Other imaging methods or analysis
Slide 26
• Vertebral fractures usually cause change in shape of the vertebrae,
but not all vertebral deformities are due to fractures.
• To differentiate fracture from deformity the interpreter takes into
account not only shape but also other features, such as the
appearance of the endplates.
• The interpretation can be aided by additional radiographic projections
such as oblique views, or by complementary examinations such as CT,
MRI, or radionuclide scans.
Relevant reference:
- Link TM et al. (2005) Radiologic assessment of osteoporotic vertebral
fractures: diagnostic and prognostic implications. Eur Radiol 15(8):
1521-32
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Slide 27
• Six point vertebral morphometry is a quantitative method of assessing
vertebral shape by placing six points on the superior and inferior
endplate at the front, mid and posterior margins. From these can be
measured the anterior (A), middle (M) and posterior (P) heights and
various ratios can be calculated.
Relevant reference:
- Guglielmi G et al. (2008) Vertebral morphometry: current methods
and recent advances. Eur Radiol 18(7): 1484-96
Slide 28, 29
• The quantitative definition of a vertebral fracture is contentious, and
in epidemiology and pharmaceutical efficacy studies a variety of six
point morphometric measurements have been used.
• In these six points are placed on the vertebral body: at the anterior,
middle and posterior point of the upper and inferior endplates.
• An alternative approach is to apply six-point video-assisted
quantitative morphometry using electronic imaging.
• These points define reductions in the anterior (wedge) and mid
(endplate) vertebral heights in relation to posterior heights to
determine change in vertebral shape, or posterior height in relation to
such height in adjacent vertebrae to determine degree of crush
fracture, or variations of these parameters.
• Although quantitative, the limitations of six point morphometry are
that the measurements may be affected by technical factors
(magnification, parallax effect of divergent X-ray beam and others)
and will not differentiate between vertebral fractures and deformities.
Slide 31
• Multi-detector computed tomography (MDCT) of the thorax and
abdomen are examinations that are widely performed for various
clinical indications.
• It is useful for midline sagittal reformations to be obtained routinely,
particularly in women over 65 and men over 70 years as vertebral
fractures will be identified on the sagittal reformations which are not
evident on the transverse axial images and which may be clinically
silent.
Slide 32
• In pathological fractures, related to such etiologies as bone
metastases or multiple myeloma, there is often cortical destruction
and bulging into the spinal canal of the posterior vertebral margin,
and other imaging techniques, such as MRI may be required for
diagnosis.
• In multiple myeloma radiographs may show generalised osteopenia,
but MRI will show diffuse infiltration and pathological fracture with
diffuse low signal intensity in T1-weighted images and high signal
intensity in T2-weighted images.
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Slide 33
• Relevant references for value of midline sagittal reformations for
incidental diagnosis of vertebral fractures on MDCT:
- Bauer JS et al. (2006) Detection of osteoporotic vertebral fractures
using multidetector CT. Osteoporos Int 17(4): 608-15
- Müller et al. (2008) Significance of sagittal reformations in routine
thoracic and abdominal multislice CT studies for detecting
osteoporotic fractures and other spine abnormalities. Eur Radiol
18(8): 1696-702
- Woo et al. (2008) Incidental vertebral fractures on multidetector CT
images of the chest: prevalence and recognition. Clin Radiol 63(2):
160-4
- Williams AL et al. (2009) Under-reporting of osteoporotic vertebral
fractures on computed tomography. Eur J Radiol 69(1): 179-83
Slide 34
• Vertebral fractures may also be evident on lateral chest radiographs,
barium studies, intravenous urograms, MDCT and MRI performed for
other clinical reasons, but are often overlooked.
Relevant references:
- Gehlbach S et al. (2000) Recognition of vertebral fracture in a clinical
setting. Osteoporos Int 11: 577-82
- Mui LW et al. (2003) Evaluation of vertebral fractures on lateral
chest radiographs of inner-city postmenopausal women. Calcif
Tissue Int 73: 550-4
- Kim N et al. (2004) Underreporting of vertebral fractures on routine
chest radiography. AJR Am J Roentgenol 182: 297-300
Slide 35
• The differential diagnosis between osteoporotic and malignant
pathological fractures may be difficult, but the presence of a soft
tissue mass, osseous destruction and fractures and retro-pulsion of
the posterior margin of the affected vertebra are features of sinister
pathology.
• CT and MRI may be helpful in differentiation.
Slide 36
• MRI is particularly useful in visualizing bone marrow pathology.
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Slide 37
• Osteoporotic fracture of L5 which shows marrow edema (low signal
on T1-weighted image; high signal on T2-weighted image and low
signal on diffusion weighted image).
Relevant reference:
- Baur A et al. (2001) Diffusion-weighted magnetic resonance imaging
of spinal bone marrow. Semin Musculoskelet Radiol 5(1): 35-42
Slide 38
• This summarises the features of malignant pathological vertebral
fractures.
Relevant reference:
- Link TM et al. (2005) Radiologic assessment of osteoporotic vertebral
fractures: diagnostic and prognostic implications. Eur Radiol 15(8):
1521-32
Slide 39
• Pathological fracture of L5 which shows marrow tumor (low signal on
T1-weighted image; high signal on T2-weighted image and high
signal on diffusion weighted image) and retro-pulsion of posterior
vertebral margin.
Relevant references:
- Baur A et al. (2001) Diffusion-weighted magnetic resonance imaging
of spinal bone marrow. Semin Musculoskelet Radiol 5(1): 35-42
- Baur-Melnyk A (2009) Malignant versus benign vertebral collapse:
are new imaging techniques useful? Cancer Imaging 9(Spec No A):
S49-51
- Dietrich O et al. (2009) Diffusion-weighted imaging of bone
marrow. Semin Musculoskelet Radiol 13(2): 134-44
Slide 40
• This illustrates the features in MRI which indicate features of multiple
metastases.
Relevant reference:
- Tehranzadeh J, Tao C (2004) Advances in MR imaging of vertebral
collapse. Semin Ultrasound CT MR 25(6): 440-60 Review
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Differential diagnosis between
fractures and deformities
Slide 42
• It is important to scrutinise carefully the shape of the vertebra and
features of the endplate to differentiate vertebral fractures from
deformities.
Relevant reference:
- Jiang G et al. (2004) Comparison of methods for the visual
identification of prevalent vertebral fracture in osteoporosis.
Osteoporos Int 15(11): 887-96
Slide 43
• It is important to scrutinise carefully the shape of the vertebra and
features of the endplate to differentiate vertebral fractures from
deformities.
Relevant references:
- Ferrar L et al. (2005) Identification of vertebral fractures: an update.
Osteoporos Int 16(7): 717-28
- Link et al. (2005) Radiologic assessment of osteoporotic vertebral
fractures: diagnostic and prognostic implications. Eur Radiol 15(8):
1521-32
- Guermazi A et al. (2002) Identification of vertebral fractures in
osteoporosis. Semin Musculoskelet Radiol 6(3): 241-52
Slide 44
• Abnormal shape of the endplate can be due to developmental
anomalies and must be differentiated from the endplate changes of
vertebral fracture.
Relevant reference for spinal developmental anomalies:
- Oskoulan RL et al. (2007) Congenital abnormalities of the thoracic
and lumbar spine. Neurosurg Clin N Am 18(3): 479-98
Slide 47
• Sheuermann’s disease (juvenile osteochondritis) affecting several,
adjacent thoracic vertebral endplates which are irregular, with slight
wedging and elongation of the vertebral bodies.
• Schmorl’s nodes in the endplates of T8 which may simulate fractures.
These tend to occur in the anterior and posterior endplates and have
sclerotic margins.
• Spondylosis in which there has occurred remodeling of the vertebral
body due to degenerative disc disease as evident by anterior marginal
osteophytes.
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Slide 48
Relevant review:
- Ali RM et al. (1999) Scheuermann's kyphosis. Curr Opin Pediatr
11(1): 70-5
Slide 49
• In spinal hemangiomas there is a coarse and sparse trabecular
pattern.
Relevant review:
- Rodallec MH et al. (2008) Diagnostic imaging of solitary tumors of
the spine: what to do and say. Radiographics 28(4): 1019-41
Slide 50, 51
•
•
•
Slide 53
There are 3 pathways that lead to the 3 alternative outcomes of
osteoporotic vertebral fracture, non-fracture deformity,
developmental variant, non-osteoporotic fracture or other
condition, and normal.
The starting point of the algorithm is “is there depression of the
vertebral endplate?” If the answer is yes, there are then further
criteria to satisfy before the observer arrives at the diagnosis of
osteoporotic vertebral fracture.
If there is no depression of the endplate, or the other criteria in
this pathway are not satisfied, the observer is directed to the
non-fracture deformity pathway and from there to the nonfracture deformity or normal outcome.
• It is vital that clinicians search for, and recognise, vertebral fractures,
on whatever imaging is available and being reviewed (spinal
radiographs, lateral chest radiographs, barium studies, MDCT of
thorax and/or abdomen [and midline sagittal reformats], MRI and
RNS).
• It is relevant to differentiate between change in vertebral shape as
due to vertebral fractures or deformities.
• If a vertebral fractures differentiate between old/new,
osteoporotic/traumatic, benign/malignant.
• Provide a clear and unambiguous report and suggest further imaging
and management, if appropriate.
Relevant review:
- Lenchik L et al. (2004) Diagnosis of osteoporotic vertebral fractures:
importance of recognition and description by radiologists. AJR Am J
Roentgenol 183(4): 949-58
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Slide 52
• In 1994 the World Health Organization (WHO) defined osteoporosis
in postmenopausal women, in terms of bone mineral densitometry
(BMD) by DXA in the lumbar spine (L1-L4), proximal femur and distal
forearm as a T-score (standard deviation [SD] score related to mean
BMD of young [20-29 years] normal Caucasian women) equal to, or
below, -2.5 was defined as osteoporosis in postmenopausal women.
• However, this was never a satisfactory BMD level for intervention, as
age is such a strong and independent determinant of fracture.
• In 2008 the WHO published a tool (FRAX®) to calculate 10-year
fracture risk for individual patients aged between 40 and 90 years
using clinical risk factors (with or without femoral neck DXA BMD).
The clinical risk factors used include age, gender, height, weight,
previous low trauma fracture over age 50, parental hip fracture, oral
glucocorticoid therapy (for more than 3 months at a dose 5mg daily
or more), rheumatoid arthritis, current smoking, alcohol consumption
(more than 3 units per day) and secondary causes of osteoporosis
(including type I [insulin dependent] diabetes, osteogenesis imperfecta
in adults, untreated long-standing hyperthyroidism, hypogonadism or
premature menopause (<45 years), chronic malnutrition, or
malabsorption and chronic liver disease).
• Subsequently national guidelines for appropriate treatment
interventions were launched in several countries. The presence of
vertebral fracture therefore influences the calculation of fracture risk
in the FRAX® tool and consequently affects management of patients.
• However, FRAX® underestimates the risk when more than one
vertebral fracture is diagnosed; both severity and number of vertebral
fractures are strong determinants of risk of further fractures. Fracture
risk prediction is also enhanced by combining vertebral fracture status
and BMD. Thus FRAX® may not be useful in patients with spinal
osteoporosis with multiple and severe vertebral fractures.
Relevant reference:
- http://www.who.int/chp/osteoporosis.pdf
- WHO publication - Kanis JA, on behalf of the World Health
Organisation Scientific Group. Assessment of osteoporosis at the
primary health care level. WHO Collaborating Centre for Metabolic
Bone Diseases, University of Sheffield 2007
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