Stephen
L. Kaufman,
Arterial . Dislocation
MD
#{149} Louis
Injuries
with
ofthe
a diagnosis
of dislocation
of the knee ban trauma
at discharge from an urhospital was performed. Nineteen patients with complete dislocation of the knee were found. Arterial injuries were seen in six patients (32%). Four of the 19 patients had no pedal pulse at physical examination In three of these four patients, occlusion of the popliteal artery was seen on arteriograms. The fourth patient had occlusion of an anomalous anterior tibial artery and a compartmental syndrome. Two of the 15 other patients with pedal pulses (13%)
had
nonocciuding
intimal
de-
fects of the popliteal artery; these two patients did well without surgery. It is concluded that abnormal peripheral pulses associated with complete knee dislocation are highly predicfive of major arterial injury. If peripheral pulses are normal, a low but definite frequency exists.
of arterial
damage
Index terms: Arteries, popliteal, 924.41 #{149} Extremities, angiography, 92.122 #{149} Knee, injuries, 458.436 5 Trauma, 458.436, 924.41
I
From
1992;
the
Complete
C
dislocation uncommon
OMPLETE
relatively
clinically important ciated with a high
to the treated, a high reports complete
poptiteat
of the knee, a injury, is
because incidence
artery,
it is assoof injury
which,
if un-
results in limb amputation in percentage of cases (1-7). Few on arterial injuries due to knee dislocation have ap-
peared
in the
indications troversial preciated nity. This
radiology
literature.
The
for arteriography are conand may not be widely apin the radiology commureport describes our study
of arterial
injuries
complete
dislocation
associated
with
of the
knee
at a
large urban trauma hospital. The purpose of our study was to determine the frequency and type of arterial injuries associated with complete dislocation of the knee and to correlate the findings at physical those at arteriography.
PATIENTS
examination
AND
with
A computerized search for patients with a diagnosis of dislocation of the knee at discharge from the hospital between January 1, 1987, and July 30, 1991, was performed at Grady Memorial Hospital, Atlanta, a level I trauma center. Nineteen patients
(14
men
and
complete dislocation found. Their medical obtained
five
women)
with
of the knee were records and the anin these
patients
of Radiology,
Emory
University School of Medicine, 1364 Clifton Rd. NE, Atlanta, GA 30322. From the 1991 RSNA scientific assembly. Received November 14, 1991; revision requested January 2, 1992; revision received February 5; accepted February 21. Address reprint requests to S.L.K. u RSNA, 1992
patients result
the knee dislocations of falls. In two patients
were
were the the disloca-
tions were the result of criminal Posterior knee dislocations were 10 patients, anterior dislocations
assaults. found in in eight
patients,
and
in one
patient. After
initial
lateral
clinical
dislocations
evaluation,
19 patients tion and
was
underwent emergency
performed
jection
by
intravenous artenography,
in the
use
of the
sedawhich
posteroanterior cut-film
or
prodigital
technique.
RESULTS The overall frequency of arterial injury was 32% (six of 19 patients). four of the 19 patients (21%), pedal pulses
were
absent
at physical
In
exami-
nation in the emergency room after closed reduction of dislocations. One of these four patients had clinical signs of severe thermia, tense
ischemia calf with
(severe hypohypoesthesia,
and diminished motor function). The three other patients without pedal pulses had only mildly decreased calf temperature. In all four patients the findings on arteriograms were abnormat. Three patients had complete occlusion of the popliteat artery at the
level of the knee joint (Fig 1). All three had patent genicular coltaterals that
METHODS
reviewed. The average age of these patients was 31 years. All patients initially entered the emergency room, where an initial physical examination was performed. The knee dislocations were caused by motor vehicle accidents in eight patients; four of these patients had been occupants of automobiles and four had been pedestrians at the time of the accident. In nine
184:153-155
Department
with
Knee
giograms Radiology
MD
Associated
To determine the frequency and type of arterial injuries associated with complete dislocation of the knee and to correlate the findings at physical examination with those at arteriography, a computerized search for patients
G. Martin,
18 of the
extended
below
the
level
of the
popli-
teat artery occlusion. All three had posterior dislocations. Angiographic findings in these three patients were confirmed at surgery. Arterial contusions
or stretch
posed
thrombosis were found.
tery underwent performed
aged
injuries
with
ar-
primary arterial repair, with excision of the dam-
segment
and
end-to-end
tomosis of the Arteriography
popliteal in the
without
pulses
sion
superim-
of the poptiteat All three patients
pedal of the
anterior
artery. fourth
revealed tibial
reanaspatient
occtu-
artery,
which originated anomalously from the popliteat artery above the level of the knee joint (Fig 2). The peroneal and posterior tibiat arteries were narrow but patent. This patient, who had an anterior knee dislocation, was the one patient who also had clinical signs
of severe
ischemia.
calf compartmental found. A fasciotomy No
direct
arterial
At surgery
a
syndrome was was performed. repair
of the
oc-
153
Figure
1. Arteriogram from a man aged 25 years with a posterior knee dislocation. The popliteal artery is occluded at the knee joint. The genicular arteries are patent. At surgery, thrombosis of the popliteal artery, with extensive intimal damage, was found.
2.
cluded anterior tibial artery was attempted. Alt four patients did well after surgery. None required amputation. The arteriograms were normal in 12 of the 15 patients in whom pedal pulses were present at physical examination. Two of these 15 patients (13%) had nonoccluding intimat defects of the popliteal artery (Fig 3), which were not repaired with surgery. One of these two patients had an anterior dislocation; the other, a lateral dislocation. Both patients have continued to show no signs of ischemia at 3 and 23 months of clinical follow-up, respectively. The 15th patient, who did not undergo arteriography, had no symptoms and had normal peripheral pulses 3 years after
injury. DISCUSSION
completely
(1,3,5).
Therefore,
due to motor vehicle accidents been the most common cause
trauma
has of com-
plete knee dislocations (3-5,7). Patients with complete knee dislocations tend to be young and mate (3,7). Anterior and posterior dislocations of the knee occur most frequently (2). Medial, lateral, and rotatory dislocations are seen less often. Because complete
154
Radiology
Figures 2, 3. (2) Arteriogram from a man aged 27 years with an anterior knee dislocation and ischemic swollen calf shows occlusion of an anterior tibial artery (arrow), which originates anomalously from the popliteal artery above the knee joint. A compartmental syndrome was found at surgery. (3) Arteriogram from a man aged 35 years with a lateral knee dislocation and normal pedal pulses shows a nonoccluding intimal defect with associated thrombus of the popliteal artery (arrow). Surgery was not performed in this patient. He was doing well at 23 months follow-up.
knee dislocations are caused by severe trauma, adjacent tissues are frequently also injured. Bone and muscle injuries, damage to the perineal and tibiat nerves, and injuries to the popliteat artery and vein are frequently associated with complete knee dislocation (1-4,6). Damage to the popliteal artery is the most serious complication of cornplete knee dislocation. Popliteat artery occlusion is seen in 29%-50% of patients with complete knee distocation and is the major cause of morbid-
ity (1-7).
Because the knee is protected by multiple dense ligaments and a sturdy capsule, a powerful force is necessary to disrupt the knee joint
3.
ered
The
poptiteal
artery
is teth-
to both the femur and the tibia (1,3,5). Whenever the knee is dislocated, the relatively immobile poptiteat artery is stretched. Popliteal artery contusions and intimat tears with superimposed thrombosis may occur. Complete transection or rupture of the poptiteal artery has been described (1,3,7). The poor collateral circulation normatty present about the knee joint causes a high risk of distal ischemia after acute poptiteal artery occlusion due to complete dislocation of the
knee. major joint.
The genicular arteries are the collateral arteries at the knee They are small and may be directly damaged by the initial injury or compressed by formation of hematoma. Impedance of blood flow in the genicutar arteries further increases the risk of leg ischemia and the need for amputation after dislocation of the knee (1,2,6). Massive trauma associated with knee dislocation may also injure the poptiteal vein. Injury to the popliteal vein has a positive correlation with need for amputation after knee dislocation (4).
In addition,
massive
muscle
trauma
in the
calf may occur and thus increase the risk of ischemia due to the development of a compartmental syndrome (3,4,6,7). The risk of amputation therefore is relatively high in
cases
of dislocation
arterial
injury higher
is much
is not than
of the
knee
if the
treated. This risk that seen in pen-
etrating trauma to the popliteal artery because of the extensive associated soft-tissue injuries associated with blunt trauma (6). Amputation may be required in up to 86% of limbs after
July
1992
complete dislocation of the knee if popliteat artery occlusion is present and timely arterial repair is not performed (2). In most studies, diagnosis of the injury and arterial repair is associated with an amputation rate of 13%-40% (2-6). With early diagnosis of arterial damage and repair of the popliteal
jury,
artery
a limb
within
salvage
can be achieved cat identification
dislocation trauma
6 hours
rate
(7). Hence, of patients
of the is needed
of in-
of up to 94%
knee
early who
after
gency fasciotomy. Normal pedal pulses were associated with a definite but low frequency of arterial injury in
sur-
our
rapid
patients.
Two
of our
15 patients
gicat management. If arterial injury is present, arterial repair should precede attempts to repair ligamentous damage. The knee joint should be stabi-
(13%) with normal pulses had nonoccluding intimal defects of the popliteal artery. These patients received conservative treatment without direct
lized
arterial repair. Both patients done well after short-term
in a cast
or splint,
and
ligamen-
tous damage should be repaired electively (3). Because complete knee dislocation may reduce spontaneously or may be reduced outside the hospital, careful examination for instability of the knee in the emergency room
is important
pedal
pulses
the
physician
jury
to the
Our
normal
(1).
in the to the
popliteal
results
of major
absence
The
of
alert
possibility
of inthat
pulses arterial
are
ab-
highly
injury.
In
all four patients without pedal pulses in our study, marked injury was seen on arteriograms. Three of the four patients had complete occlusion of the popliteal artery. None of these three patients had symptoms of se-
Volume
184
e
Number
1
indications
for
with
absence
Acknowledgments: the computerized noses and Dana manuscript.
1.
have follow-up.
arteriography
of pedal
in
2.
3.
4.
pulses
and with signs of acute clinical ischemia of the leg, time is of the essence
5.
and one may cause the site
6.
popliteal pulses
of acute
forgo arteriography of injury is usually
artery. are
absent
ischemia
arteriography define the
Whenever and
exist,
no
bethe
pedal other
If such
defects
are not
repaired by means of surgery, as in the two patients with such defects in our study, close clinical follow-up for symptoms of distal ischemia is necessary. U We thank Trina search for discharge Hall for the preparation
Smith for diagof the
References
complete dislocation of the knee have been controversial. Signs of severe clinical ischemia have a positive correlation with the eventual need for limb amputation (6,7). Therefore, in patients
artery.
demonstrate
peripheral
predictive
The
leg should
be performed.
clinihave
major
to enable
phy in these patients may be performed at the radiologist’s discretion. Because delayed thrombosis may occur in patients with nonocctuding intimal defects (3), arterial repair may
vere ischemia, likely because of the presence of collateral genicular arteries. The fourth patient in whom pedal pulses were absent had occlusion of the anterior tibial artery, which was directly caused by the dislocation, and a compartmental syndrome caused by associated soft-tissue damage. This patient had severe symptoms of ischemia and required emer-
signs
emergency
should be performed to site of injury, which may not always be the popliteal artery, and the status of the peripheral circulalion. Arterial abnormality has a tow but definite frequency among patients with normal pedal pulses. Arteriogra-
7.
Lefrak EA. Knee dislocation: an illusive cause of critical arterial occlusion. Arch Surg 1976; 111:1021-1024. Green NE, Allen BL. Vascular injuries associated with dislocation of the knee. J Bone Joint Surg [Am] 1977; 59:236-239. O’Donnell TF Jr. Brewster DC, Darling RC, et al. Arterial injuries associated with fractures and/or dislocations of the knee. Trauma 1977; 17:775-783. Alberty RE, Goodfried G, Boyden AM. Popliteal artery injury with fractural dislocation of the knee. Am J Surg 1981; 142:36-40. Welling RE, Kakkasseril J, Cranley JJ. Complete dislocations of the knee with popliteal vascular injury. J Trauma 1981; 21:450-453. Snyder WH III. Vascular injuries near the knee: an updated series and overview of the problem. Surgery 1982; 91:502-506. Wagner WH, Calkins ER, Weaver FA, et al. Blunt popliteal artery trauma: one hundred consecutive injuries. J Vasc Surg 1988; 7:736-743.
Radiology
e
155
L. Kaufman,
Arterial . Dislocation
MD
#{149} Louis
Injuries
with
ofthe
a diagnosis
of dislocation
of the knee ban trauma
at discharge from an urhospital was performed. Nineteen patients with complete dislocation of the knee were found. Arterial injuries were seen in six patients (32%). Four of the 19 patients had no pedal pulse at physical examination In three of these four patients, occlusion of the popliteal artery was seen on arteriograms. The fourth patient had occlusion of an anomalous anterior tibial artery and a compartmental syndrome. Two of the 15 other patients with pedal pulses (13%)
had
nonocciuding
intimal
de-
fects of the popliteal artery; these two patients did well without surgery. It is concluded that abnormal peripheral pulses associated with complete knee dislocation are highly predicfive of major arterial injury. If peripheral pulses are normal, a low but definite frequency exists.
of arterial
damage
Index terms: Arteries, popliteal, 924.41 #{149} Extremities, angiography, 92.122 #{149} Knee, injuries, 458.436 5 Trauma, 458.436, 924.41
I
From
1992;
the
Complete
C
dislocation uncommon
OMPLETE
relatively
clinically important ciated with a high
to the treated, a high reports complete
poptiteat
of the knee, a injury, is
because incidence
artery,
it is assoof injury
which,
if un-
results in limb amputation in percentage of cases (1-7). Few on arterial injuries due to knee dislocation have ap-
peared
in the
indications troversial preciated nity. This
radiology
literature.
The
for arteriography are conand may not be widely apin the radiology commureport describes our study
of arterial
injuries
complete
dislocation
associated
with
of the
knee
at a
large urban trauma hospital. The purpose of our study was to determine the frequency and type of arterial injuries associated with complete dislocation of the knee and to correlate the findings at physical those at arteriography.
PATIENTS
examination
AND
with
A computerized search for patients with a diagnosis of dislocation of the knee at discharge from the hospital between January 1, 1987, and July 30, 1991, was performed at Grady Memorial Hospital, Atlanta, a level I trauma center. Nineteen patients
(14
men
and
complete dislocation found. Their medical obtained
five
women)
with
of the knee were records and the anin these
patients
of Radiology,
Emory
University School of Medicine, 1364 Clifton Rd. NE, Atlanta, GA 30322. From the 1991 RSNA scientific assembly. Received November 14, 1991; revision requested January 2, 1992; revision received February 5; accepted February 21. Address reprint requests to S.L.K. u RSNA, 1992
patients result
the knee dislocations of falls. In two patients
were
were the the disloca-
tions were the result of criminal Posterior knee dislocations were 10 patients, anterior dislocations
assaults. found in in eight
patients,
and
in one
patient. After
initial
lateral
clinical
dislocations
evaluation,
19 patients tion and
was
underwent emergency
performed
jection
by
intravenous artenography,
in the
use
of the
sedawhich
posteroanterior cut-film
or
prodigital
technique.
RESULTS The overall frequency of arterial injury was 32% (six of 19 patients). four of the 19 patients (21%), pedal pulses
were
absent
at physical
In
exami-
nation in the emergency room after closed reduction of dislocations. One of these four patients had clinical signs of severe thermia, tense
ischemia calf with
(severe hypohypoesthesia,
and diminished motor function). The three other patients without pedal pulses had only mildly decreased calf temperature. In all four patients the findings on arteriograms were abnormat. Three patients had complete occlusion of the popliteat artery at the
level of the knee joint (Fig 1). All three had patent genicular coltaterals that
METHODS
reviewed. The average age of these patients was 31 years. All patients initially entered the emergency room, where an initial physical examination was performed. The knee dislocations were caused by motor vehicle accidents in eight patients; four of these patients had been occupants of automobiles and four had been pedestrians at the time of the accident. In nine
184:153-155
Department
with
Knee
giograms Radiology
MD
Associated
To determine the frequency and type of arterial injuries associated with complete dislocation of the knee and to correlate the findings at physical examination with those at arteriography, a computerized search for patients
G. Martin,
18 of the
extended
below
the
level
of the
popli-
teat artery occlusion. All three had posterior dislocations. Angiographic findings in these three patients were confirmed at surgery. Arterial contusions
or stretch
posed
thrombosis were found.
tery underwent performed
aged
injuries
with
ar-
primary arterial repair, with excision of the dam-
segment
and
end-to-end
tomosis of the Arteriography
popliteal in the
without
pulses
sion
superim-
of the poptiteat All three patients
pedal of the
anterior
artery. fourth
revealed tibial
reanaspatient
occtu-
artery,
which originated anomalously from the popliteat artery above the level of the knee joint (Fig 2). The peroneal and posterior tibiat arteries were narrow but patent. This patient, who had an anterior knee dislocation, was the one patient who also had clinical signs
of severe
ischemia.
calf compartmental found. A fasciotomy No
direct
arterial
At surgery
a
syndrome was was performed. repair
of the
oc-
153
Figure
1. Arteriogram from a man aged 25 years with a posterior knee dislocation. The popliteal artery is occluded at the knee joint. The genicular arteries are patent. At surgery, thrombosis of the popliteal artery, with extensive intimal damage, was found.
2.
cluded anterior tibial artery was attempted. Alt four patients did well after surgery. None required amputation. The arteriograms were normal in 12 of the 15 patients in whom pedal pulses were present at physical examination. Two of these 15 patients (13%) had nonoccluding intimat defects of the popliteal artery (Fig 3), which were not repaired with surgery. One of these two patients had an anterior dislocation; the other, a lateral dislocation. Both patients have continued to show no signs of ischemia at 3 and 23 months of clinical follow-up, respectively. The 15th patient, who did not undergo arteriography, had no symptoms and had normal peripheral pulses 3 years after
injury. DISCUSSION
completely
(1,3,5).
Therefore,
due to motor vehicle accidents been the most common cause
trauma
has of com-
plete knee dislocations (3-5,7). Patients with complete knee dislocations tend to be young and mate (3,7). Anterior and posterior dislocations of the knee occur most frequently (2). Medial, lateral, and rotatory dislocations are seen less often. Because complete
154
Radiology
Figures 2, 3. (2) Arteriogram from a man aged 27 years with an anterior knee dislocation and ischemic swollen calf shows occlusion of an anterior tibial artery (arrow), which originates anomalously from the popliteal artery above the knee joint. A compartmental syndrome was found at surgery. (3) Arteriogram from a man aged 35 years with a lateral knee dislocation and normal pedal pulses shows a nonoccluding intimal defect with associated thrombus of the popliteal artery (arrow). Surgery was not performed in this patient. He was doing well at 23 months follow-up.
knee dislocations are caused by severe trauma, adjacent tissues are frequently also injured. Bone and muscle injuries, damage to the perineal and tibiat nerves, and injuries to the popliteat artery and vein are frequently associated with complete knee dislocation (1-4,6). Damage to the popliteal artery is the most serious complication of cornplete knee dislocation. Popliteat artery occlusion is seen in 29%-50% of patients with complete knee distocation and is the major cause of morbid-
ity (1-7).
Because the knee is protected by multiple dense ligaments and a sturdy capsule, a powerful force is necessary to disrupt the knee joint
3.
ered
The
poptiteal
artery
is teth-
to both the femur and the tibia (1,3,5). Whenever the knee is dislocated, the relatively immobile poptiteat artery is stretched. Popliteal artery contusions and intimat tears with superimposed thrombosis may occur. Complete transection or rupture of the poptiteal artery has been described (1,3,7). The poor collateral circulation normatty present about the knee joint causes a high risk of distal ischemia after acute poptiteal artery occlusion due to complete dislocation of the
knee. major joint.
The genicular arteries are the collateral arteries at the knee They are small and may be directly damaged by the initial injury or compressed by formation of hematoma. Impedance of blood flow in the genicutar arteries further increases the risk of leg ischemia and the need for amputation after dislocation of the knee (1,2,6). Massive trauma associated with knee dislocation may also injure the poptiteal vein. Injury to the popliteal vein has a positive correlation with need for amputation after knee dislocation (4).
In addition,
massive
muscle
trauma
in the
calf may occur and thus increase the risk of ischemia due to the development of a compartmental syndrome (3,4,6,7). The risk of amputation therefore is relatively high in
cases
of dislocation
arterial
injury higher
is much
is not than
of the
knee
if the
treated. This risk that seen in pen-
etrating trauma to the popliteal artery because of the extensive associated soft-tissue injuries associated with blunt trauma (6). Amputation may be required in up to 86% of limbs after
July
1992
complete dislocation of the knee if popliteat artery occlusion is present and timely arterial repair is not performed (2). In most studies, diagnosis of the injury and arterial repair is associated with an amputation rate of 13%-40% (2-6). With early diagnosis of arterial damage and repair of the popliteal
jury,
artery
a limb
within
salvage
can be achieved cat identification
dislocation trauma
6 hours
rate
(7). Hence, of patients
of the is needed
of in-
of up to 94%
knee
early who
after
gency fasciotomy. Normal pedal pulses were associated with a definite but low frequency of arterial injury in
sur-
our
rapid
patients.
Two
of our
15 patients
gicat management. If arterial injury is present, arterial repair should precede attempts to repair ligamentous damage. The knee joint should be stabi-
(13%) with normal pulses had nonoccluding intimal defects of the popliteal artery. These patients received conservative treatment without direct
lized
arterial repair. Both patients done well after short-term
in a cast
or splint,
and
ligamen-
tous damage should be repaired electively (3). Because complete knee dislocation may reduce spontaneously or may be reduced outside the hospital, careful examination for instability of the knee in the emergency room
is important
pedal
pulses
the
physician
jury
to the
Our
normal
(1).
in the to the
popliteal
results
of major
absence
The
of
alert
possibility
of inthat
pulses arterial
are
ab-
highly
injury.
In
all four patients without pedal pulses in our study, marked injury was seen on arteriograms. Three of the four patients had complete occlusion of the popliteal artery. None of these three patients had symptoms of se-
Volume
184
e
Number
1
indications
for
with
absence
Acknowledgments: the computerized noses and Dana manuscript.
1.
have follow-up.
arteriography
of pedal
in
2.
3.
4.
pulses
and with signs of acute clinical ischemia of the leg, time is of the essence
5.
and one may cause the site
6.
popliteal pulses
of acute
forgo arteriography of injury is usually
artery. are
absent
ischemia
arteriography define the
Whenever and
exist,
no
bethe
pedal other
If such
defects
are not
repaired by means of surgery, as in the two patients with such defects in our study, close clinical follow-up for symptoms of distal ischemia is necessary. U We thank Trina search for discharge Hall for the preparation
Smith for diagof the
References
complete dislocation of the knee have been controversial. Signs of severe clinical ischemia have a positive correlation with the eventual need for limb amputation (6,7). Therefore, in patients
artery.
demonstrate
peripheral
predictive
The
leg should
be performed.
clinihave
major
to enable
phy in these patients may be performed at the radiologist’s discretion. Because delayed thrombosis may occur in patients with nonocctuding intimal defects (3), arterial repair may
vere ischemia, likely because of the presence of collateral genicular arteries. The fourth patient in whom pedal pulses were absent had occlusion of the anterior tibial artery, which was directly caused by the dislocation, and a compartmental syndrome caused by associated soft-tissue damage. This patient had severe symptoms of ischemia and required emer-
signs
emergency
should be performed to site of injury, which may not always be the popliteal artery, and the status of the peripheral circulalion. Arterial abnormality has a tow but definite frequency among patients with normal pedal pulses. Arteriogra-
7.
Lefrak EA. Knee dislocation: an illusive cause of critical arterial occlusion. Arch Surg 1976; 111:1021-1024. Green NE, Allen BL. Vascular injuries associated with dislocation of the knee. J Bone Joint Surg [Am] 1977; 59:236-239. O’Donnell TF Jr. Brewster DC, Darling RC, et al. Arterial injuries associated with fractures and/or dislocations of the knee. Trauma 1977; 17:775-783. Alberty RE, Goodfried G, Boyden AM. Popliteal artery injury with fractural dislocation of the knee. Am J Surg 1981; 142:36-40. Welling RE, Kakkasseril J, Cranley JJ. Complete dislocations of the knee with popliteal vascular injury. J Trauma 1981; 21:450-453. Snyder WH III. Vascular injuries near the knee: an updated series and overview of the problem. Surgery 1982; 91:502-506. Wagner WH, Calkins ER, Weaver FA, et al. Blunt popliteal artery trauma: one hundred consecutive injuries. J Vasc Surg 1988; 7:736-743.
Radiology
e
155
