J ANUARY,
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THE
TUMBLING POST-TRAUMATIC
RICHARD
By
N.
BULLET SIGN IN BONE CYST*
TAXIN,
M.D.,
and
YORK,
NEW
NEW
LTHOUGH for the bone cysts are always
roentgenographic recognition of well established,
serve
other lesions.
to
lution
of
despite entity
The
developed
bullet first
wound from the
that
its
case
that
are
still
as
male
a result
of a
documented
trauma; diagnostic
and of
within the confines its cYstic rather
old
a
of dual interest; point of view
was
movement
as
year
i
cyst
is, therefore, pathogenetic
evolution
free
cysts
of a
a bone
corollary of the roentgen
radiolucent and evo-
their acceptance for many decades.
following
who
M.D.t
YORK
distinguish solid etiology
bone
unicameral
unsettled pathologic
FELDMAN,
A
criteria unicameral they do not
definitively
similarly situated In addition, the
FRIEDA
1975
secondly, point of the
in
as
a
from view
foreign
in body
of the lesion established than solid nature. vs
REPORT
A
year
ic
emergency gunshot entered the
(Fig. or
I of
medullary ). There
a
of the
noted.
The
ing
room
lin.
An
and
clicking
right
knee.
bullet, now
well
elevated (Fig.
3)
Professor
demonstrated
the
Department of Radiology.
bullet
had
lodged
saline
and
and
penicil-
of
aqueous
area
with
to with
sistent second
shaft
reveals
of the
distal oval 1
2,
his
medial contain let.
which and
the
Columbia-Presbyterian
the surgery aspect
the
femur, shaped,
right
bullet
femur.
was
it
femur plane moved
latter was
cm. distal
thoroughly of
with
oxacillin
Center,
oil
knee
not
New
cavity
and
packed
cells
the membrane and scar New
York.
with
bone was tissue
size.
wall,
mm. was
a later,
a bul-
cyst
was
per-
centerofound to and
the
There
The
in
fluid and 0.5-I
curetted.
York,
prompted months
increased
like”
the
A
cyst in the femur was
retrieved
infection.
Microscopically, of histiocytic
I 40
had
a 4X6 of the
of
position.
about the intervention
lesion
was
portion in
approximately
dence
Medical
dependent change
a “machinery
The
which
B).
most each
dull ache operative
At
a
of that
to the horizontal that the bullet of Radiology,
the
freely lesion
although
within
(Fig.
‘-
roentgenogram
within
of
locking
lodged in the by a large,
Initial
I.
cortical
revealed
position
FIG.
incidentally in the operat-
intravenously. later, he complained
sensation
a
The
Fibrous were
the
distal femur of fracture
units
roentgenograms perpendicular
C From
.t
site.
with
lucent
to change
Adiitinal
the
Roentgenograms
demarcated
and
of the evidence
4,000,000
although still surrounded
appeared
laterally
irrigated
seen in sustaining
knee.
and tibia was debrided
were given months
painless
right
at
femur wound
additional
penicillin Sixteen
was
was
was after
cavity no gross
lesion
cystic
defects
the
thigh
CASE
male hours
2
of his
A
white
wound
had ill
old room
OF
thick, no
cvi-
irrigated chips. composed which ac-
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VOL.
123,
No.
The
i
F
2.
Tumbling
(if
....&
and
focal
plasma
spicules,
cells.
fibrous
and
in a Post-Traumatic
#{163} ,
of a large
aggregates
Several tissue
Sign
,,,
margin
coinmodated
Bullet
of
radiolucent
a few
new
of
dead bone were also noted. There was no cvidence of osteomyclitis. Cultures of the cyst fluid were unremarkable. Cell count revealed I.I million red blood cells and
white
300,000
blood
cells
per
patient received oxacillin and was placed in a long leg cast.
mm.’.
The
ampicillin
and
DISCUSSION
The currently both the roentgen for
a simple
camera! clinically consistently
or
bone occult
unicameral unless associated
bone
are
most
satisfied criteria
margins.
plate, cone.
occasionally Its transverse
usually plate.5
does not Two-thirds
found
in
the
cyst.
Uni-
fractured, biochemical
with
or
physical abnormalities.3 They may be mitially diagnosed by the radiologist on the basis ofa combination of”classic findings.” These include the presence of a centrally located radiolucent metaphyseal lesion in a long bone of a young child. The cyst commonly thins and expands the cortex symmetrically with its base oriented towards
a
proximal
humerus
and
distal
femur.3 Although
common,
these
classic
criteria
are inconstant and, more significantly, not pathognomonic. Similar roentgen acteristics may be shared by such lesions
radiolucent
tion.
The the
as
which,
tary, within no
simulating diameter
exceed that of the growth of the lesions have been
andenchondroma
commonly
‘4’
defined
intramedullary
reported lesion and pathologic cysts
well
the growth truncated
bone
fragments
with
Cyst
bt
r demonstrate
,,,
lesion
lymphocytes
reactive
Bone
free
and
fall
confines
fibrous
also,
dysplasia
may
metaphyseal
of
a radiopaque
of such
are charsolid
a lesion,
be soliin loca-
body there-
fore, provides an important clue as to its internal architecture. The diagnostic implications of a foreign body moving within a hollow or fluid filled structure have previously been discussed in relation to retroperitoneal
abscesses6
and
as
a sign
of intra-
venous migration, while the changing position of a segment of fractured cortex has proved useful in the diagnosis of unicameral bone cyst.
Richard
Downloaded from www.ajronline.org by 104.239.165.217 on 06/21/16 from IP address 104.239.165.217. Copyright ARRS. For personal use only; all rights reserved
I 42
3.
Lateral
bullet
let
now
view
falls
to
with the femur the superior
lesion, which in this dependent portion, cystic nature.
position thereby
The
is unique
current
entered
splintering
case the or
N.
Taxin
elevated.
i
margin
of
becomes its demonstrating
and
r the
most its
medullary obviously
in that cavity
a bulwithout
fracturing
the
cor-
a bone portion bullet
it is a bullet
in an
abscess
cavity,6
fragment falling to the dependent of a cyst or, as in the above case, a falling freely within a fluid filled
post-traumatic
bone
cyst,
the
principle
of
the “Tumbling Bullet” or “Fallen Fragment”8 is a simple one; i.e., that of a heavier object being able to move freely in a lighter environment. The current case, however, is of further interest in documenting the post-traumatic evolution of a unicameral bone cyst, and thereby substantiating one of the theories
Feldman
JANUARY,
1975
of its pathogenesis. The development of a bone cyst from the time of its inception has rarely been observed. Two cases reported by Broder’ appeared to develop at the site of pre-existing osseous abnormalities, which roentgenographically had the appearance of nonossifying fibromas or calcified cartilage rests. One of these lesions was eccentrically placed. Neither patient had sustained trauma. Pommer7 proposed that the solitary bone cyst results from a focus of intramedullary hemorrhage which then becomes encapsulated. Continued transudation of fluid into the cyst with increasing internal pressure was held responsible for erosion of neighboring trabeculae and continued cortical expansion. Since an ordinary fracture with cortical and periosteal disruption presumably prevents the formation of a closed pressure system, the possibility of mild trauma without fracture but with intramedullary hemorrhage was entertained as an etiologic possibility. By the same token, unicameral bone cysts have been noted to heal or fill in after spontaneous fracture. Although Cohen’s more recent theory2 suggests a relationship between fluid accumulation
vessel bosis,
tex and remained to serve as a reliable sign of the cystic nature of the resultant lesion. Whether
Frieda
sufficient
and
on the basis he felt that etiologic
occlusion
of
a
sinusoidal
of trauma and/or thromtrauma alone was an infactor.
Developmental anomalies of microscopic sized vessels have also been suggested to explain both the development and predominantly metaphyseal localization of these lesions. This concept envisages an abnorma! proliferation of sinusoidal vessels in the rapidly remodelling metaphyseal zone. Resultant inadequate communication with the vascular system might coincidentally result in an increased susceptibility of these vessels to partial block or occlusion after minimal trauma. An obstacle to the normal drainage of interstitial fluid is, therefore, postulated which may be aggravated by trauma. These speculations could account for one consistent characteristic of bone cysts; i.e., their metaphyseal predilec-
Downloaded from www.ajronline.org by 104.239.165.217 on 06/21/16 from IP address 104.239.165.217. Copyright ARRS. For personal use only; all rights reserved
VOL.
123,
No.
i
The
Tumbling
Bullet
tion, while the currently reported established an instance where could be directly incriminated.
Sign
in a Post-Traumatic bone
case has trauma
Bone 7. Bone
cysts.
Cyst
& Joint
I 43
Surg.,
1968,
50-A,
503-507. 2.
COHEN,
Surg., 3.
J. Simple bone cysts. 1960, p-A, 6o-6i6.
H. L., and
JAFFE,
cameral
SUMMARY
Arc/i.
cyst.
& Joint
L. Solitary
LICHTENSTEIN,
bone
Bone
7.
Surg.,
uni44,
1942,
1004-1025.
Various hypotheses for the etiology of unicameral bone cysts are discussed. The unique documentation of a lesion which developed as a result of a bullet wound appears to lend credence to trauma as an inciting agent.
4.
5.
RAD.
7.
10032
BRODER,
H. M. Possible
sign
of
of
unicameral
222,
190-
bone
cyst:
ROENTGENOL., MED.,
8o,
1958,
G.
17,
REYNOLDS, unitameral
949-953.
J. B. Tumbling
SHIELDS,
retroperitoneal
97,
‘970,
POMMER,
of precursor
NUCLEAR
E., and
MITFOCHOLZOR,
1920,
8. I.
J.
AM.
&
THERAPY
abscess.
Radi-
625-627.
Zur
H#{228}matom und Rohrenknochen.
622
REFERENCES
“tumbling
495-504.
ology,
Center
of
1972,
unicameral
reappraisal.
bullet: Medical
7.A.M.A.,
G. S. Juvenile
LODWICK, roentgen
Radiology
West i68th Street New York, New York
G. L. Sign
IRvIN,
revisited.
191.
M.D.
Columbia-Presbyterian
J., and
bullet”
6.
Frieda Feldman, Department of
LEPAGE,
Kenntnis
der
progressiven
Phlegmasiever#{228}nderungen Arch.
orthop.
u
der
UnJall-C/zir.
17.
J. “Fallen bone
fragment cysts.
sign”
Radio/ogy,
in diagnosis 1969,
92,
Downloaded from www.ajronline.org by 104.239.165.217 on 06/21/16 from IP address 104.239.165.217. Copyright ARRS. For personal use only; all rights reserved
THE
TUMBLING POST-TRAUMATIC
RICHARD
By
N.
BULLET SIGN IN BONE CYST*
TAXIN,
M.D.,
and
YORK,
NEW
NEW
LTHOUGH for the bone cysts are always
roentgenographic recognition of well established,
serve
other lesions.
to
lution
of
despite entity
The
developed
bullet first
wound from the
that
its
case
that
are
still
as
male
a result
of a
documented
trauma; diagnostic
and of
within the confines its cYstic rather
old
a
of dual interest; point of view
was
movement
as
year
i
cyst
is, therefore, pathogenetic
evolution
free
cysts
of a
a bone
corollary of the roentgen
radiolucent and evo-
their acceptance for many decades.
following
who
M.D.t
YORK
distinguish solid etiology
bone
unicameral
unsettled pathologic
FELDMAN,
A
criteria unicameral they do not
definitively
similarly situated In addition, the
FRIEDA
1975
secondly, point of the
in
as
a
from view
foreign
in body
of the lesion established than solid nature. vs
REPORT
A
year
ic
emergency gunshot entered the
(Fig. or
I of
medullary ). There
a
of the
noted.
The
ing
room
lin.
An
and
clicking
right
knee.
bullet, now
well
elevated (Fig.
3)
Professor
demonstrated
the
Department of Radiology.
bullet
had
lodged
saline
and
and
penicil-
of
aqueous
area
with
to with
sistent second
shaft
reveals
of the
distal oval 1
2,
his
medial contain let.
which and
the
Columbia-Presbyterian
the surgery aspect
the
femur, shaped,
right
bullet
femur.
was
it
femur plane moved
latter was
cm. distal
thoroughly of
with
oxacillin
Center,
oil
knee
not
New
cavity
and
packed
cells
the membrane and scar New
York.
with
bone was tissue
size.
wall,
mm. was
a later,
a bul-
cyst
was
per-
centerofound to and
the
There
The
in
fluid and 0.5-I
curetted.
York,
prompted months
increased
like”
the
A
cyst in the femur was
retrieved
infection.
Microscopically, of histiocytic
I 40
had
a 4X6 of the
of
position.
about the intervention
lesion
was
portion in
approximately
dence
Medical
dependent change
a “machinery
The
which
B).
most each
dull ache operative
At
a
of that
to the horizontal that the bullet of Radiology,
the
freely lesion
although
within
(Fig.
‘-
roentgenogram
within
of
locking
lodged in the by a large,
Initial
I.
cortical
revealed
position
FIG.
incidentally in the operat-
intravenously. later, he complained
sensation
a
The
Fibrous were
the
distal femur of fracture
units
roentgenograms perpendicular
C From
.t
site.
with
lucent
to change
Adiitinal
the
Roentgenograms
demarcated
and
of the evidence
4,000,000
although still surrounded
appeared
laterally
irrigated
seen in sustaining
knee.
and tibia was debrided
were given months
painless
right
at
femur wound
additional
penicillin Sixteen
was
was
was after
cavity no gross
lesion
cystic
defects
the
thigh
CASE
male hours
2
of his
A
white
wound
had ill
old room
OF
thick, no
cvi-
irrigated chips. composed which ac-
Downloaded from www.ajronline.org by 104.239.165.217 on 06/21/16 from IP address 104.239.165.217. Copyright ARRS. For personal use only; all rights reserved
VOL.
123,
No.
The
i
F
2.
Tumbling
(if
....&
and
focal
plasma
spicules,
cells.
fibrous
and
in a Post-Traumatic
#{163} ,
of a large
aggregates
Several tissue
Sign
,,,
margin
coinmodated
Bullet
of
radiolucent
a few
new
of
dead bone were also noted. There was no cvidence of osteomyclitis. Cultures of the cyst fluid were unremarkable. Cell count revealed I.I million red blood cells and
white
300,000
blood
cells
per
patient received oxacillin and was placed in a long leg cast.
mm.’.
The
ampicillin
and
DISCUSSION
The currently both the roentgen for
a simple
camera! clinically consistently
or
bone occult
unicameral unless associated
bone
are
most
satisfied criteria
margins.
plate, cone.
occasionally Its transverse
usually plate.5
does not Two-thirds
found
in
the
cyst.
Uni-
fractured, biochemical
with
or
physical abnormalities.3 They may be mitially diagnosed by the radiologist on the basis ofa combination of”classic findings.” These include the presence of a centrally located radiolucent metaphyseal lesion in a long bone of a young child. The cyst commonly thins and expands the cortex symmetrically with its base oriented towards
a
proximal
humerus
and
distal
femur.3 Although
common,
these
classic
criteria
are inconstant and, more significantly, not pathognomonic. Similar roentgen acteristics may be shared by such lesions
radiolucent
tion.
The the
as
which,
tary, within no
simulating diameter
exceed that of the growth of the lesions have been
andenchondroma
commonly
‘4’
defined
intramedullary
reported lesion and pathologic cysts
well
the growth truncated
bone
fragments
with
Cyst
bt
r demonstrate
,,,
lesion
lymphocytes
reactive
Bone
free
and
fall
confines
fibrous
also,
dysplasia
may
metaphyseal
of
a radiopaque
of such
are charsolid
a lesion,
be soliin loca-
body there-
fore, provides an important clue as to its internal architecture. The diagnostic implications of a foreign body moving within a hollow or fluid filled structure have previously been discussed in relation to retroperitoneal
abscesses6
and
as
a sign
of intra-
venous migration, while the changing position of a segment of fractured cortex has proved useful in the diagnosis of unicameral bone cyst.
Richard
Downloaded from www.ajronline.org by 104.239.165.217 on 06/21/16 from IP address 104.239.165.217. Copyright ARRS. For personal use only; all rights reserved
I 42
3.
Lateral
bullet
let
now
view
falls
to
with the femur the superior
lesion, which in this dependent portion, cystic nature.
position thereby
The
is unique
current
entered
splintering
case the or
N.
Taxin
elevated.
i
margin
of
becomes its demonstrating
and
r the
most its
medullary obviously
in that cavity
a bulwithout
fracturing
the
cor-
a bone portion bullet
it is a bullet
in an
abscess
cavity,6
fragment falling to the dependent of a cyst or, as in the above case, a falling freely within a fluid filled
post-traumatic
bone
cyst,
the
principle
of
the “Tumbling Bullet” or “Fallen Fragment”8 is a simple one; i.e., that of a heavier object being able to move freely in a lighter environment. The current case, however, is of further interest in documenting the post-traumatic evolution of a unicameral bone cyst, and thereby substantiating one of the theories
Feldman
JANUARY,
1975
of its pathogenesis. The development of a bone cyst from the time of its inception has rarely been observed. Two cases reported by Broder’ appeared to develop at the site of pre-existing osseous abnormalities, which roentgenographically had the appearance of nonossifying fibromas or calcified cartilage rests. One of these lesions was eccentrically placed. Neither patient had sustained trauma. Pommer7 proposed that the solitary bone cyst results from a focus of intramedullary hemorrhage which then becomes encapsulated. Continued transudation of fluid into the cyst with increasing internal pressure was held responsible for erosion of neighboring trabeculae and continued cortical expansion. Since an ordinary fracture with cortical and periosteal disruption presumably prevents the formation of a closed pressure system, the possibility of mild trauma without fracture but with intramedullary hemorrhage was entertained as an etiologic possibility. By the same token, unicameral bone cysts have been noted to heal or fill in after spontaneous fracture. Although Cohen’s more recent theory2 suggests a relationship between fluid accumulation
vessel bosis,
tex and remained to serve as a reliable sign of the cystic nature of the resultant lesion. Whether
Frieda
sufficient
and
on the basis he felt that etiologic
occlusion
of
a
sinusoidal
of trauma and/or thromtrauma alone was an infactor.
Developmental anomalies of microscopic sized vessels have also been suggested to explain both the development and predominantly metaphyseal localization of these lesions. This concept envisages an abnorma! proliferation of sinusoidal vessels in the rapidly remodelling metaphyseal zone. Resultant inadequate communication with the vascular system might coincidentally result in an increased susceptibility of these vessels to partial block or occlusion after minimal trauma. An obstacle to the normal drainage of interstitial fluid is, therefore, postulated which may be aggravated by trauma. These speculations could account for one consistent characteristic of bone cysts; i.e., their metaphyseal predilec-
Downloaded from www.ajronline.org by 104.239.165.217 on 06/21/16 from IP address 104.239.165.217. Copyright ARRS. For personal use only; all rights reserved
VOL.
123,
No.
i
The
Tumbling
Bullet
tion, while the currently reported established an instance where could be directly incriminated.
Sign
in a Post-Traumatic bone
case has trauma
Bone 7. Bone
cysts.
Cyst
& Joint
I 43
Surg.,
1968,
50-A,
503-507. 2.
COHEN,
Surg., 3.
J. Simple bone cysts. 1960, p-A, 6o-6i6.
H. L., and
JAFFE,
cameral
SUMMARY
Arc/i.
cyst.
& Joint
L. Solitary
LICHTENSTEIN,
bone
Bone
7.
Surg.,
uni44,
1942,
1004-1025.
Various hypotheses for the etiology of unicameral bone cysts are discussed. The unique documentation of a lesion which developed as a result of a bullet wound appears to lend credence to trauma as an inciting agent.
4.
5.
RAD.
7.
10032
BRODER,
H. M. Possible
sign
of
of
unicameral
222,
190-
bone
cyst:
ROENTGENOL., MED.,
8o,
1958,
G.
17,
REYNOLDS, unitameral
949-953.
J. B. Tumbling
SHIELDS,
retroperitoneal
97,
‘970,
POMMER,
of precursor
NUCLEAR
E., and
MITFOCHOLZOR,
1920,
8. I.
J.
AM.
&
THERAPY
abscess.
Radi-
625-627.
Zur
H#{228}matom und Rohrenknochen.
622
REFERENCES
“tumbling
495-504.
ology,
Center
of
1972,
unicameral
reappraisal.
bullet: Medical
7.A.M.A.,
G. S. Juvenile
LODWICK, roentgen
Radiology
West i68th Street New York, New York
G. L. Sign
IRvIN,
revisited.
191.
M.D.
Columbia-Presbyterian
J., and
bullet”
6.
Frieda Feldman, Department of
LEPAGE,
Kenntnis
der
progressiven
Phlegmasiever#{228}nderungen Arch.
orthop.
u
der
UnJall-C/zir.
17.
J. “Fallen bone
fragment cysts.
sign”
Radio/ogy,
in diagnosis 1969,
92,
