First Case:
     This is a 2-month-old female who is brought to an 
acute care clinic for cough, runny nose, fussiness, and 
decreased movement of the left arm.  The infant has 
mild nasal congestion, bilateral otitis media, and an 
angulated tender swelling in the left upper arm with 
minimal movement of the left arm.
     According to the mother, the infant cries a lot when 
she is dressed and has not been moving her arm for 
approximately 3 days.  The mother also notes swelling, 
but is uncertain about the day of onset.  She said that 
the father told her that while he was cleaning the house, 
he tripped over the infant's brother and accidentally 
stepped on the baby.  She did not seek medical 
attention earlier because she thought the arm was just 
sore from the incident.
     A skeletal survey is done.

View lower extremity:

      The left distal femur metaphysis is shown here.  
Three images are displayed.  The top image is taken on 
the day of presentation to the E.D.  Corner fractures on 
both sides of the distal femur are barely visible.  The 
middle image, taken two days later, shows the two 
corner fractures more clearly.  The bottom image, taken 
9 days after presentation shows some periosteal 
reaction.  The pattern of healing shows a bucket handle 
appearance at the inferior border of the metaphysis.

View upper extremity:

     The upper extremity radiograph shows a 
transverse fracture of the mid-portion of the shaft of the 
left humerus.
     In addition to the fractures displayed above, this 
patient also has a small bucket handle fracture of the 
distal humeral metaphysis and a small bucket handle 
fracture of the distal tibia. Both of these are very hard to 
see (images not shown).  These findings are compatible 
with child abuse.
     A CT scan of the head is normal, and an inpatient 
ophthalmologic evaluation does not reveal any retinal 
hemorrhages.

View diagram of fractures.

     This diagram illustrates the phenomenon of corner 
fractures and bucket handle fractures.  Corner fractures 
and bucket handle fractures are similar in etiology 
despite their different names.  A small bucket handle 
fracture may appear as a corner fracture on the 
radiograph depending on the angle of the radiograph.  A 
true corner fracture is still similar to a small bucket 
handle fracture.

Second Case:
     This is a 9-month-old who is brought to an acute 
care clinic after noting something is wrong with the 
infant's arm after a toy was pulled away from him.  The 
infant was in the care of the baby-sitter at that time.  
Mother was working at night.
     Physical exam reveals a 9-month-old male, 
approximately 50th percentile for height and weight.  A 
bruise at the lateral edge of the left eye and bruise of 
the left pinnae are noted.  The child is clinging to the 
mother, quite apprehensively.  The right elbow shows 
2+ swelling.  The child is reluctant to move the right 
elbow because of pain.  The sensation and circulation 
to the hand appears normal.  Above the right elbow, 
ecchymosis is noted anteriorly and posteriorly.  No 
definite crepitus is detected.  The infant holds the right 
elbow in full extension.  Any flexion beyond 10-15 
degrees results in pain, with the child crying.
     A skeletal survey is obtained.

View right elbow.

     Multiple views of the right elbow demonstrate a 
distal humeral bucket handle type fragment.  The thin 
fragment represents a section of the distal metaphysis.  
Although the physis (growth plate) cannot be seen 
radiographically, it is evident that the fracture must go 
through the physis to splinter off a section of the distal 
metaphysis as seen.  The radius should be pointing at 
the capitellum in all views.  In the oblique lateral view, 
the radius is not pointing straight at the capitellum 
indicating that the epiphysis of the humerus (capitellum) 
is displaced.  The AP view shows that the capitellum is 
displaced medially.  This type of fracture is known in the 
orthopedic literature as a "transepiphyseal" 
(transphyseal) fracture.  This is not a true bucket handle 
fracture, although it resembles a bucket handle.  
     A follow-up view of this elbow is taken one month 
later.

View follow-up view of elbow.

     Extensive periosteal reaction and healing are noted 
in the distal humeral metaphysis.  What initially 
appeared to be a small fracture upon presentation, 
results in substantial changes associated with healing.  
Most of the fracture is through the physis, however, this 
is not ossified and not visible radiographically.  These 
extensive changes are evidence of healing of the 
"transepiphyseal" fracture.

View patient's tibia.

     The lower extremity radiographs demonstrate 
periosteal new bone formation along the lateral aspect 
of the shaft of the left tibia, presumably secondary to a 
healing subperiosteal hematoma.  This finding is very 
subtle and can be best seen on the AP view on the 
lateral aspect adjacent to the fibula.

View focused view of tibia.

     This focused view of the patient's tibia points to the 
area of periosteal reaction.

     A technetium bone scan is recommended to 
determine if there are any other skeletal injuries, which 
cannot be visualized radiographically.  A radionuclide 
bone scan with vascular flow scan is performed.

View bone scan.

     Delayed static images of the bone scan showed 
increased tracer localization in multiple sites, including 
the left clavicle, both humeri (R>L), both ulnae (not 
shown), and both tibiae (L>R).  Findings were felt to be 
most likely traumatic in etiology.
     Images obtained soon after injection ("blood pool"), 
are mainly a function of blood flow and the degree of 
soft tissue hyperemia.  The early images are useful in 
the diagnosis of infectious and traumatic lesions, as 
well as malignant bone tumors.  After a delay of 2-4 
hours, the concentration of the phosphate compound by 
the bone is a function of its osteogenic activity and 
blood flow.  Since many conditions can alter the degree 
of tracer localization, it is particularly important to 
correlate the abnormalities in bone scan with detailed 
radiographic views of the involved areas and with the 
clinical situation to come to an accurate diagnostic 
impression.

Discussion:  Child Abuse Fractures

1.  Epiphyseal-Metaphyseal Fractures
     Injuries at the epiphyseal-metaphyseal junction are 
highly suggestive of abuse.  The periosteum 
surrounding the growing long bones is thick and tightly 
anchored at both ends by heavy extensions into the 
epiphyseal cartilages.  In contrast, the highly 
vascularized, loosely attached young periosteum of the 
diaphysis is easily torn from its underlying cortex.  The 
resultant subperiosteal bleeding lifts the periosteum, 
forming layers of periosteal new bone away from the 
cortex to form an external shell of new bone.
     This extremely strong periosteum that is tightly 
anchored by heavy extensions into the epiphyseal 
cartilages can easily explain the dynamics of 
epiphyseal-metaphyseal fractures.  Axial ligament and 
periosteal traction or torsion forces are generated by 
sudden traction on the extremity, such as occurs when 
the arms or legs are pulled or swung violently upward or 
forward.  This results in the typical traction "corner" 
fracture pathognomonic of child abuse.  These are 
well-visualized in the cases described above.

2.  Metaphyseal Fractures
     Metaphyseal fractures were first described by Caffey 
in 1972, who felt they represented an indirect avulsion 
injury to the metaphysis by the pull of the periosteum 
when the child was severely shaken.  In 1983, 
Kleinman and Zito showed these to be transverse 
fractures through the metaphysis and only appeared to 
be avulsion injuries because of the radiographic 
projection views.  If the metaphysis is tipped or simply 
projected obliquely to the X-ray beam, the margin of the 
resultant fragment is projected with a bucket-handle 
appearance.  If the peripheral fragment is substantially 
thicker than the central fragment, and the plane of injury 
is viewed tangentially, a corner fracture appearance 
results.  Note the potential radiographic appearance of 
the injuries diagrammed earlier.

View diagram of these injures.

     These authors believed that metaphyseal fractures 
were most suggestive of abuse.  Reed has pointed out 
that these metaphyseal fractures can be seen in other 
orthopedic conditions, including rickets, scurvy, multiple 
congenital contractures, and kinky-hair syndrome.

3.  Diaphyseal Fractures
     Diaphyseal fractures can be grouped into three 
broad categories:  1) Transverse, spiral, and oblique 
shaft fractures.  2) Multiple fractures in various stages 
of healing.  3) Bony deformity.
     A spiral or oblique fracture is produced by a twisting 
mechanism, while a transverse fracture is caused by a 
direct blow.

     Technetium 99 bone scanning has been shown to 
be highly sensitive when used to assess skeletal injury, 
particularly in occult areas not easily accessible to 
clinical examination.  The scan is frequently "hot" for 
many weeks during healing.  The bone scan can be 
especially useful in identifying fractures of flat bones, 
such as the skull, ribs and scapulae, which may be 
missed on radiographic films.

     In summary, radiographic findings indicating child 
abuse include epiphyseal-metaphyseal fractures, such 
as "corner" / "bucket-handle" fractures, and 
subperiosteal hematoma bone formation as described 
above.  Consultation with an experienced radiologist will 
often be helpful in determining the etiology of the injury.

References
     1.  Black GV.  Child abuse fractures.  In: Letts RM.  
Management of Pediatric Fractures, 1994, New York, 
Churchill Livingston, pp. 931-944.
     2.  Caffey J.  On the theory and practice of shaking 
infants.  Am J Dis Child 1972:124:161.
     3.  Kleinman PK, Zito JL.  Skeletal injury in the 
young battered infant: An expanded radiologic 
spectrum.  Presented to the 26th Annual Meeting of the 
Society for Pediatric Radiology.  Atlanta, April 1983.
     4.  Reed MH.  Pediatric Skeletal Radiology.  1992, 
Baltimore, Williams & Wilkins.