Jeremy Tucker, HMS IV
Gillian Lieberman, MD
November 2003
Metaphyseal and
Rib Fractures in
Child Abuse
Jeremy Tucker, Harvard Medical School, Year IV
Gillian Lieberman, MD, Beth Israel Deaconess Hospital
and Harvard Medical School
1
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
In real life, no one tells
you that the topic of the
patient presentation is
child abuse.
2
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Presentation of patient:
•5 month old female presented to
Children’s hospital with decreased
mobility of her right lower
extremity.
•The baby was visiting her father
when she rolled off a bed.
•After she was returned to her
mother, her aunt noticed that she
was not using her leg and suggested
bringing her to her doctor.
•Her mother called for an
appointment several days later.
3
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Plain films of right leg included the following:
Fibula
Tibia
Talus
Calcaneus
Navicular
4
Case courtesy of Paul Kleinman, Children’s Hospital Boston
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Look again:
5
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Note the transverse radiolucencies running through the
subphyseal regions of the metaphyses.
6
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Skeletal survey also included the following:
Normal or
Abnormal?
7
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Look again: Abnormal
Rib thickening due to callus
pushing in pleural surface
Rib thickening due to callus
accentuated by bronchus below
8
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
A different view of ribs:
Osteoschlerosis and
sub-periosteal new
bone formation are
also signs of fracture
healing.
9
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Callus formation
Subperiosteal bone formation
Osteosclerosis
„ All signs of fracture healing…
„ Not consistent with new
fractures
10
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Conclusion based on
Radiology Findings:
•Classic metaphyseal lesions NOT consistent with story
of patient falling off bed
•Healing of old fractures NOT consistent with story of
patient falling off bed
•Both quality and long-standing nature of fractures gave
radiologists a high suspicion of child abuse in case of
this 5 month old girl.
11
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Child Abuse
Each Year
•3 million reports to DSS
•1 million substantiated
•600,000 seriously harmed
•2,000 die
12
Courtesy of Paul Kleinman
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Child Abuse
Each Year
•3 million reports to DSS
•1 million substantiated
•600,000 seriously harmed
•2,000 die
•Psychological morbidity unmeasurable
13
Courtesy of Paul Kleinman
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Why focus on skeletal injuries?
„
Skeletal injuries not usually life threatening
and usually heal well
High diagnostic value
„ Common findings in abused babies
„ Skeletal survey is highly sensitive test for
abuse
„
14
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Skeletal injuries
Distribution of 165
inflicted fractures in 31
fatally abused children
•64 Classic Metaphyseal
Lesions
•84 rib lesions
15
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Highly specific bone findings
„
„
„
„
„
Classic metaphyseal lesions*
Rib fractures, especially posterior*
Scapular fractures
Spinous process fractures
Sternal fractures
*also highly common, occur in almost all abused
children
16
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Classic metaphyseal
lesions
Also know as “corner fractures” and
“bucket-handle fractures”
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Metaphyseal lesion that
looks like a corner of the
bone is fractured.
Metaphyseal lesion that looks
like a bucket handle.
18
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Now,
remove from your
vocabulary:
“corner fractures” and “bucket-handle
fractures”
Courtesy of Paul Buonano, Boston Children’s Hospital
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
The appearance of a corner fracture or a bucket handle fracture
depends on the angle of radiograph projection. But these are part
of the same fragment which is in the shape of a disc or frisbee.
We will therefore refer to this fracture as a Classic Metaphyseal
Lesion.
20
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
ChondroOsseous
Junction
Physis: Chondrocytes
grow in zones of
proliferation and
hypertrophy and then
calcify matrices
between their columns
in zone of provisional
calcification.
(growth plate or epiphyseal plate)
Metaphysis: vascular
channels invaded
chondrocytes but
intercolumnar
calcification persists,
eventually becoming
mineralized osteoid.
(distal metaphysis = primary
spongiosa)
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
21
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Normal COJ
Subphyseal Metaphysis
COJ
Physis
hypertrophied
chondrocytes
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
22
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Physis Physiology
1.
2.
3.
Chondrocytes proliferate and then enlarge in a
columnar organization with a terminal
chondrocyte at edge of physis.
Metaphyseal vasculature sends a signal to
terminal chondrocyte which causes it to undergo
a morpholgical change: cell begins to apoptose
or somehow to be released.
Metaphyseal vasculature invades the lacuna of
the changing chondrocyte.
Rogers, Lee. Radiology of Skeletal Trauma, Third Edition. 2002.
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
23
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Why the physis doesn’t
disappear:
„
Vascular invasion of chondrocyte lacunae is
BALANCED by chondrocyte proliferation deep in
the physis plate, distal to the COJ.
„
Metaphyseal vasculature allows for extension of
metaphysis into physis
Epiphyseal vasculature allows for proliferation of
chondrocytes from mother cell
„
24
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Why the classic metaphyseal
lesion forms in the distal
metaphysis:
The most vulnerable part of the bone in an
infant is the distal metaphysis (aka primary
spongiosa)
„ Having no chondrocytes makes it weaker
than physis.
„ Fewer organized cells and less calcification
makes it weaker than the more proximal
parts of metaphysis or the rest of the bone.
„
25
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Therefore, Classic Metaphyseal
Lesions:
Are planar fractures, not corners or rings
„ Occur in the metaphysis, not the physis
„ Are “virtually pathognomonic” for abuse
„ Result from repeated torsional and shearing
forces
„
Kleinman et al. “The Metaphyseal Lesion in Abused Infants: A Radiologic-Histopathologic Study.” AJR:
26
146, May 1986..
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Shearing and torsional forces which lead to CML’s:
27
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
The shape of the calcified
segment below the CML
Frisbee or disk-like
„ Centrally the calcified segment is thin
„ Peripherally the calcified segment is thicker
„
Why?
28
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Why the CML is shaped like a
frisbee:
„
„
„
Thick subperiosteal bone collar surrounds the thin
cartilage network of the distal metaphysis and the
hypertrophied chondrocytes of the adjacent physis
Fractures therefore tend to cut under the bone
collar.
This produces the corner fracture appearance from
a perspective tangential to the bone.
Kleinman et al. “The Metaphyseal Lesion in Abused Infants: A Radiologic-Histopathologic
Study.” AJR: 146, May 1986..
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
29
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Normal COJ and CML shape
Bone Collar
30
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Acute CML Changes
Subperiosteal bone collar
Subperiosteal bone collar
Calcified disc fragment:
thin layer of primary
spongiosa of metaphysis +
zone of hypertrophic
chondrocytes within the
zone of provisional
calcification + bone collar
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
31
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
The calcified portion of fractured
segment:
1.
2.
3.
Thin portion of metaphyseal primary
spongiosa
Zone of provisional calcification with the
hypertrophic chondrocytes of physis
Bone collar at the periphery of fragment
Courtesy of Paul Kleinman lecture
32
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Radiographic alterations: acutely
„
„
„
If no displacement of the fragment occurs, or if
angle of projection is oblique to the fracture, the
radiographic image may look normal
If some degree of displacement occurs in the plane
of the projection, transverse lucency is seen in the
subphyseal region of metaphysis
Fracture line may be apparent in one projection
and invisible in another
33
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Chronically, what happens?
„
„
„
„
„
„
Metaphyseal vessels damaged
= loss of signal that normally leads to morphologic
death/differentiation of terminal chondrocyte.
PERSISTENCE rather than DEMISE of terminal
chondrocyte = osseous growth arrest
Epiphyseal vessels undamaged = chondrocyte proliferation
continues
Abnormal survival of cells causes net increase in cell
number present within cartilage column.
= Metaphysis does not invade physis column
Rang, Mercer. The growth plate and its disorders. Baltimore, Williams and Wilkins Company, 1969.
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998
34
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Healing of Focal Metaphyseal Injury
1. Terminal chondrocytes persist ONLY in focally
damaged columns where transformation into
bone is blocked.
2. Damaged columns blocked from calcification
3. Uncalcified region extends into calcified region
35
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Histologic view:
Extension of
metaphysis into
normal hypertrophic
chondrocytes
Radiographic view:
Focal Metaphyseal
Radiolucencies
(inconspicuous fx)
36
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Healing of extensive
metaphyseal injury
„Chondrocytes accumulate
at COJ, resulting in
increased thickness in zone
of provisional calcification
„Fragment appears to
thicken on radiograph
„Cessation of
endochondral bone growth
„Diffuse widening of
physis
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
37
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Recall our patient:
Healing of an extensive metaphyseal
injury led to diffuse widening of the
calcified zone of the physis.
Courtesy of Paul Kleinman at Boston Children’s Hospital
38
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
The second major finding in our
patient’s radiographs:
Hints of:
Rib Fractures
39
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Why Get Images of Ribs in a
Case involving a leg?
„
„
„
„
„
„
Suspicion of abuse
Central to radiologic diagnosis of abuse
Usually rib fractures NOT suspected clinically
51% of fxs in fatally abused children involve ribs
Posterior rib fractures are highly specific for child
abuse (especially after ruling out metabolic
disorders, skeletal dysplasias, and MVA’s)
Therefore a skeletal survey of ribs is both sensitive
and specific for child abuse
40
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Let’s Review Anatomy:
Costo-chondral junction
Rib Head
Costo-transverse
process articulation
Rib Tubercle
Transverse Process facet
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
41
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Rib Head Apophysis
Transverse
Process Apophysis
42
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Which parts of the ribs fracture
most often in cases of abuse?
Mostly rib head and rib neck
„ In a study of 63 abused children, 87% of rib
fractures were either at the head or the neck
„ Fractures of rib head and neck are very
rarely from any cause other than abuse or a
severe motor vehicle accident
„
Rogers, Lee. Radiology of Skeletal Trauma, Third Edition. 2002.
Kleinman,PK. “Factors Affecting Visualization of Posterior Rib Fractures in Abused Infants.” AJR
150, March 1988.
43
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Rib head and neck fractures
•No fx visible on frontal projection
•Disruption of Ventral bone cortex at rib
head (short arrows) and rib neck (long
arrows) often difficult to visualize (>50%)
Kleinman,PK. “Factors Affecting Visualization of Posterior Rib Fractures in Abused Infants” AJR
150, March 1988.
44
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Mechanism of Rib Fracture
Thoracic compression with free posterior motion:
45
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Mechanism of fracture
„
„
„
Excessive leverage of rib over transverse process
consistent with fracture features
Classic type 1 lever:
‹ Force on ventral portion of rib
‹ Fulcrum at articulation between transverse
process and rib
‹ Loading (pull) on costovertebral articulation
Costovertebral ligaments stronger than rib, so
mechanical failure over point of fulcrum
46
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
•Front to back force with free posterior rib motion
•Excessive leverage over costo-transverse process
fulcrum
•Fractures at maximal points of strain (ventral
portion of rib at neck and head, dorsal portion
elsewhere)
•Studies with rabbits support compression mech.
47
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Rib Head fractures
„
„
„
„
„
Extend from ventral cortex of rib into costoosseous junction
Conforms to growth plate fractures described by
Salter and Harris
Often not visible on frontal image if no
displacement and fx oblique to plane of x-ray
If visible, subtle verticle lucency at extreme
medial aspect of rib
Heal with fibrosis and increased osteoblastic
activity, visible radiographically after several
weeks
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
48
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Rib Head
Fracture Healing
Right posterior ribs,
third through eighth,
show widening on
frontal radiograph
Right posterior
rib, sixth, shows
fracture callus at
rib head.
49
„Lonergan GJ. Radiographics 2003; 23: 811-846.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Rib Neck Fractures
•Ventral surface fracture
(location of maximal strain)
•Line through medullary cavity
•Reaches dorsal cortex
•In tact rib head cartilage (*)
•In tact rib tubercle cartilage
(diamond)
50
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Rib Neck Fracture Healing
Callus
formation
over rib neck
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
51
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Rib Neck Fracture Healing
•Acute posterior rib neck
fractures: right 4th, 5th, and
6th possible
•Callus indicating healing of
rib fractures: right 4th,5th,
and 6th rib. (Also callus at
inferior margins of left 6th
and 7th)
52
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Thoracic compression:
•Gripping is most common cause of compression
•Similar force vector and rib motion if infant slammed on face or hurled
face forward at an immobile object, as rib arcs free to move posteriorly,
causing excessive leverage
Lonergan, GL, et al. Radiographics, July-Aug 2003, v23, n4.
53
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Review: Highly specific bone
fractures
Classic metaphyseal lesions
„ Rib fractures, especially posteriorly at head
and neck
„ Scapular fractures
„ Spinous process fractures
„ Sternal fractures
„
54
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Moderate specificity fractures
„
„
„
„
„
Multiple fractures of different ages
Epiphyseal separations (Salter fx of elbow where
radial line does not intersect capitabulum)
Vertebral body fractures (C2 pedicle fx of
“Hangman’s”
Digital fractures (buckling of cortical bone)
Skull fractures (occipital region fx, often ass. w/
soft tissue injury)
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
55
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Common fractures with LOW
specificity for child abuse
„
„
„
„
Subperiosteal new bone formation
Clavicular fractures
Long bone shaft fractures (transverse or
oblique/spiral-- poor correlation shown between
pattern of shaft fx and inflicted vs. accidental
injury, although direct forces cause transverse fx
and torsional forces cause oblique fx)
Linear skull fractures
56
Kleinman, PK. Diagnostic Imaging of Child Abuse, Second Edition. 1998.
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Protocol
„
„
„
Problem: acutely most fxs very difficult to see on
plain film
Solutions:
‹ Full skeletal surveys vs. specific bone film
‹ Follow up surveys needed to see callus
formation
‹ Bone scans (nuclear medicine scintigraphy)
needed to see fractures acutely
Rule out metabolic abnormalities and other causes
Exact protocol depends on age of child and findings.
Protocol decisions will not be addressed here.
57
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Let’s now return to our patient
„
Classic metaphyseal lesions consistent with repetitive
torsional forces more than 1 week prior to exam
„
Rib fractures consistent with compressional force more
than 1 week prior to exam
58
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
What was the outcome for this 5
month old little baby?
„
„
„
„
„
„
Social worker met with her mother.
Child protection team consulted and reviewed her
films.
Department of social services met with her
mother.
Her mother disclosed a 2nd fall from a bed a few
weeks previously.
DSS not satisfied with new explanation
Child protection team ultimately went to court on
the baby girl’s behalf.
59
Courtesy of Paul Kleinman, Boston Children’s Hospital
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
References
„
„
„
„
„
„
„
„
„
Caffey J. Multiple factures in the long bones of infants suffering from chronic subdural hematoma.
AJR 1946, 56:163-173.
Keats T, Smith T. An Atlas of Normal Developmental Roentgen Anatomy. Chicago, Year Book
Medical Publishers, 1988.
Kleinman PK. Diagnostic Imaging of Child Abuse, Second Edition. St. Louis, Mosby, Inc. 1998.
Kleinman PK, Marks SC, Adams VI, Blackbourne BD. Factors affecting visualization of posterior
rib fractures in abused infants. AJR 1988, 150: 635-638.
Kleinman PK, Marks SC, Blackbourne BD. The metaphyseal lesion in abused infants: a radiologichistopathologic study. AJR 1986; 146: 898-905.
Lonergan GJ, Baker AM, Morey MK, Boos SC. Child Abuse: Radiologic-Pathologic Correlation.
Radiographics 2003; 23: 811-846.
Rang, Mercer. The growth plate and its disorders. Baltimore, Williams and Wilkins Company, 1969.
Rockwood C, Wilkins K. Fractures in Children, Fourth Edition, Volume 3. Philidelphia, Lippincott
Publishers, 1996.
Rogers, Lee. Radiology of Skeletal Trauma, Third Edition. Philidelphia, Churchill Livingston, 2002.
Reading maketh a full man, conference maketh a ready man, and writing an exact man. -Bacon
60
Jeremy Tucker, HMS IV
Gillian Lieberman, MD
Acknowledgements
Paul K Kleinman, MD, Boston Children’s
Hospital
„ Jesse Wei, MD, BIDMC Radiology
„ Damon Soeiro, MD, BIDMC Radiology
„ Carlo Buonomo, MD, Boston Children’s
Hospital
„ Gillian Lieberman, MD BIDMC
„ Pamela Lepkowski, BIDMC Radiology
„
61