Vol. 23, No.

10 October 2001 871

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Additional
Radiographic Views of
the Pelvis and Pelvic
KEY FACTS
Limb in Dogs*
■ The dorsal acetabular rim view Kansas State University
may demonstrate evidence of H. T. Meier, DVM
degenerative changes. D. S. Biller, DVM, DACVR
M. Lora-Michiels, MV†
■ Femoral neck fractures may be J. J. Hoskinson, DVM, DACVR
better evaluated using the flexed
ventrodorsal view.
ABSTRACT: Several studies have described additional radiographic views of the pelvis and
■ Better evaluation of the talocrural pelvic limb that may help diagnose specific osseous abnormalities in dogs. For example, dis-
joint can be obtained with a traction views of the coxofemoral joints have been described in the assessment of hip dyspla-
dorsoplantar skyline view. sia. Veterinarians may find this summary paper useful because it provides a single source of
information on selected additional radiographic views of the canine coxofemoral, stifle, and
tarsal joints. These views will be applicable when osseous lesions are poorly visualized on rou-
tine views.

T
his article describes routine radiographic views, common indications,
and diseases for which radiographic evaluation of the canine pelvic limb
and pelvis is necessary. Also provided are written and photographic de-
scriptions of how to obtain many additional radiographic views (Table 1). It is
important for practitioners to remember that radiographic lesions may not be vi-
sualized even if there are clinical signs present because of the origin or early stage
of a disease process.

COXOFEMORAL JOINT
Routine radiography of the coxofemoral joint includes mediolateral and ex-
tended ventrodorsal views.1,2 Radiographs help diagnose common coxofemoral
joint abnormalities such as fractures, neoplasia, and ligamentous instability lead-
ing to osteoarthrosis. A thorough history and physical examination must be ob-
*A companion article entitled “Additional Radiographic Views of the Thoracic Limb in
Dogs” appeared in the September 2001 (Vol. 23, No. 9) issue of Compendium.
†
Dr. Lora-Michiels is now affiliated with North Carolina State University.
872 Small Animal/Exotics Compendium October 2001

Table 1. Radiographic Views for Detecting Various Osseous Abnormalities of the Pelvic Limb
Joint View Indications
Hip PennHip®, stress ventrodorsal view, dorsal acetabular rim view, Fractures, neoplasia, ligamentous
flexed ventrodorsal view instability, osteoarthrosis

Stifle Caudocranial (medial or lateral) stress view, skyline view Osteochondrosis, fractures, neoplasia,
of the patella ligamentous instability

Tarsus Plantarodorsal oblique view, hyperextended or hyperflexed Osteochondrosis, fractures, neoplasia,

mediolateral view, dorsoplantar flexed skyline view, ligamentous instability
plantarodorsal (medial or lateral) bending force view

tained to determine the region of radiographic interest. the table, and the stifles should be internally rotated
Dogs with hip dysplasia usually present with clinical while applying a craniodorsal push (Figure 1).6
signs of pelvic limb lameness, reluctance to rise and The dorsal acetabular rim may demonstrate evidence
exercise, and pain on hip extension and flexion. The of degenerative changes that are secondary to hip dys-
Orthopedic Foundation for Animals recommends rou- plasia or trauma. Routine views of the coxofemoral
tine extended ventrodorsal views for evaluating hip dys- joint are usually inadequate for visualization of the dor-
plasia.3 Additional views used to assess hip dysplasia in- sal acetabular rim. Therefore, if assessment of this re-
clude distraction and compression of the coxofemoral gion is indicated, a dorsal acetabular view should be ob-
joint.4,5 Only PennHIP®-certified veterinarians are able tained. This view will allow the best visualization of the
to perform these techniques; therefore, these techniques acetabular rim and femoral head. To obtain this view,
are not described in this paper. For veterinarians who the patient should be placed in sternal recumbency
are not PennHIP®-certified, a stress ventrodorsal view with the hindlimbs pulled cranially. The femurs should
can be used to evaluate dysplasia because it allows as- be parallel to the long axis of the body. The tarsus
sessment of coxofemoral joint laxity. To obtain this should be elevated from the table by a 2-inch spacer to
view, the patient should be positioned in dorsal recum- allow the ischium to be more cranial with respect to the
bency. The femurs should be placed at a 60˚ angle from sacrum (Figure 2).7

Figure 1A Figure 1B
Figure 1—(A) Demonstration of patient positioning for a stress ventrodorsal view of the coxofemoral joint. The stifles are inter-
nally rotated, and a craniodorsal force is applied to the femurs (arrow). (B) Stress ventrodorsal radiographic view of the cox-
ofemoral joint. This radiograph reveals no coxofemoral joint abnormalities. Note the adequate congruency of the femoral head
within the acetabulum bilaterally.
Compendium October 2001 Small Animal/Exotics 873

Figure 2A Figure 2B
Figure 2—(A) Demonstration of patient positioning for a dorsal acetabular rim view. A restricting device has been used to allow
the femurs to be parallel with the long axis of the body. Note how the tarsus is slightly elevated with the use of a sandbag (arrow).
(B) Dorsal acetabular rim radiographic view of the coxofemoral joint. This view allows visualization of the dorsal acetabular rim
without superimposition of other osseous structures (arrows). (A = sacrum; B = wing of the ilium; C = femoral head.)

Dogs that present with a history of trauma to the be used to assess femoral head and neck traumatic le-
proximal femur and have clinical signs of focal swelling, sions because it allows a different view of the proximal
crepitation, and hindlimb lameness should be radi- femoral anatomy (Figure 3).8
ographed to determine the extent of the trauma. Rou-
tine radiography may not definitively diagnose femoral STIFLE
neck fractures due to superimposition of osseous struc- Routine radiography of the stifle includes mediolat-
tures or inadequate x-ray beam orientation through the eral and caudocranial views. 1,2 Stifle radiography is
fracture site (not tangential to fracture site). Therefore, helpful when diagnosing common lesions such as os-
a flexed ventrodorsal view of the coxofemoral joint may teochondrosis, fractures, neoplasia, and ligamentous in-
stability leading to os-
teoarthrosis.
Common clinical signs
of ligamentous instability
or avulsion fractures in-
clude weight-bearing to
non–weight-bearing lame-
ness, joint effusion, pain
on palpation, and joint
laxity (cranial cruciate rup-
ture or collateral ligament
rupture). Routine stifle ra-
diography usually will not
adequately diagnose these
lesions. Therefore, stress
radiography should be
Figure 3A Figure 3B
used to assess ligamentous
Figure 3—(A) Routine ventrodorsal radiographic view of the coxofemoral joint. The left femoral instability or small avul-
neck has radiolucent defects when compared with the contralateral neck. (B) Flexed ventrodorsal sion fractures.9 To obtain
radiographic view of the coxofemoral joint. Note how a fracture of the left femoral neck (arrows) these views, the patient
is better visualized when compared with the routine ventrodorsal view seen in Figure 3A. This is
should be placed in sternal
because the x-ray beam is now tangential to the femoral neck.
recumbency. The stifle
874 Small Animal/Exotics Compendium October 2001

should be gently pushed laterally with a wooden spoon

to evaluate the medial region. This same technique can
be performed to evaluate the lateral region of the stifle
(Figure 4). In a recent report, mediolateral radiography
of the stifle in neutral and compression positions were
obtained to assess the degree of tibial displacement with
respect to the femur. Significant differences were not
found between normal stifles and joints with partial
cranial cruciate ligament rupture. This report conclud-
ed that tibial displacement could not be used to assess
the degree of cranial cruciate damage.10
Fractures, inflammatory disease, or patella luxation
can be visualized using a nonroutine skyline view. The
skyline view allows transverse and articular visualization
of the patella and trochlear ridges of the femur. To ob-
tain this view, the patient should be placed in sternal
recumbency. The affected pelvic limb should be flexed
while the femur is positioned perpendicular to the
tabletop. The x-ray beam should be vertically centered
over the patella (Figure 5).2,11,12
Figure 4—Bending force stress radiographic view of the medial
TARSUS portion of the stifle joint. Note the abnormal widening of the
lateral portion of the joint. This is consistent with ligamen-
Routine radiography of the tarsus includes mediolat- tous instability such as lateral collateral ligamentous rupture.
eral and plantarodorsal views.1,2 Tarsal radiography can
be used to diagnose common
abnormalities such as osteo-
chondrosis, trauma (e.g., lux-
ations, fractures), neoplasia,
and ligamentous instability
leading to osteoarthrosis.
Dogs that present with his-
torical tarsal trauma usually
have clinical signs of non–
weight-bearing lameness and
tarsal joint effusion as well as
possible crepitation and joint Figure 5B
laxity. Fractures of individual
tarsal bones (e.g., central
tarsal bone fractures) that are
seen in racing greyhounds are
usually challenging to diag-
nose because of osseous su-
perimposition on standard
routine views.13–15 These and
other osteochondral lesions
can be diagnosed by using
oblique views.2,16–19 To obtain
a dorsomedial to plantarolat- Figure 5A Figure 5C
eral oblique view, the patient Figure 5—(A) Demonstration of patient positioning for a skyline view of the patella. The af-
should be placed in sternal re- fected stifle is oriented on the cassette so the patella is tangential to the x-ray beam (arrow). (B
cumbency. The distal limb and C) Skyline radiographic views of the patella. Note the focal lucent defect on the cranial
should be internally rotated aspect of the patella that was diagnosed as osteomyelitis (arrow in C). This defect is visualized
and the x-ray beam centered because the x-ray beam was tangential to the proximodistal osseous margins of the patella.
876 Small Animal/Exotics Compendium October 2001

vertically on the tarsus. This view will allow adequate vi- Tarsal ligamentous injuries, osteochondral fragments,
sualization of the dorsolateral and plantaromedial mar- and osteochondral fractures that may not be identified
gins of the tarsal bones. To obtain a dorsolateral to plan- on routine radiographic views can be identified using
taromedial oblique view, the patient should be placed in additional traction force stress views.9 To obtain these
sternal recumbency and the distal limb externally rotat- views, the patient should be placed in sternal recum-
ed (Figure 6). This view will allow adequate visualiza- bency and the affected tarsus positioned on a cassette.
tion of the dorsomedial and plantarolateral margins of The tarsus should be gently distracted proximally and
the tarsal bones. We have made these oblique views rou- distally. Bending forces can be applied to open the joint
tine practice when evaluating fractures. medially or laterally as described for the carpus. These
We use oblique views to identify osteochondral le- views may demonstrate widening of the medial or later-
sions because they allow better visualization of view-de- al region of the tarsus if ligamentous instability is pres-
pendent osseous margins. Additionally, other nonrou- ent. To obtain these views, the affected tarsus should be
tine views have been described to further assess placed on the cassette while the patient is in sternal re-
osteochondrosis. Hyperextended and hyperflexed later- cumbency. The lateral region of the tarsus can be evalu-
al views can be obtained for the affected region of the ated by gently bending the medial region of the tarsus
condyle.17,20 A flexed dorsoplantar skyline view of the with a wooden spoon (Figure 8). This stress view can
talocrural joint can also be obtained to visualize the ar- be obtained for the medial region of the joint using the
ticular margin of the distal tibia, the lateral malleolus, same technique.
and the nonsuperimposed articular surface of the
trochlear ridges of the talus.21 To obtain a dorsoplantar CONCLUSION
skyline view, the patient should be placed in dorsal re- Additional radiographic views of the canine pelvis
cumbency and the tarsal joints placed on a cassette ele- and pelvic limb may be necessary to diagnose challeng-
vated from the table with a box or stand. The x-ray ing lesions that are not seen on routine views because of
beam should be centered at the affected talocrural joint. osseous superimposition. This paper outlines several
The tarsus should be flexed until it forms a 10˚ to 15˚ additional views that can be used to better visualize
angle with the x-ray beam (Figure 7). This may also be these challenging orthopedic lesions. They are easy to
a good view to determine whether the distal tibial frac- obtain with practice and may potentially provide a
ture is articular. definitive diagnosis.

Figure 6A
Figure 6—(A) Demonstration of patient positioning for a dorsolateral to plantarome-
dial oblique view of the tarsal joint (arrow). The patient is placed in sternal recum-
bency. The affected tarsal joint is caudally extended and placed on the cassette. (B)
Dorsolateral to plantaromedial oblique radiographic view of the tarsal joint. Note
the subluxation of the central tarsal bone consistent with a central tarsal bone frac-
ture (arrow). This oblique view allows visualization of the dorsomedial portion of
the tarsal joint. Osseous superimposition of the central tarsal bone occurs with rou-
tine views.
Figure 6B
Compendium October 2001 Small Animal/Exotics 877

Figure 7A Figure 7B
Figure 7—(A) Demonstration of patient positioning for a flexed dorsoplantar skyline view of the talocrural joint. A restricting device (A) has
been placed around the stifles to help align the tarsal joints, a box (B) is used to elevate the distal portion of the pelvic limbs so the tarsal
joints are in best contact with the cassette, and a wooden spoon (C) is used to angle the talocrural joint space with the x-ray beam. (B)
Flexed dorsoplantar skyline radiographic view of the talocrural joint. Note the nonsuperimposed articular surface of the trochlear ridges of
the talus. The calcaneus is no longer superimposed over this joint space. (A = medial malleolus; B = lateral malleolus; C = proximal phalanx.)

REFERENCES
1. Ticer JW: Radiographic Technique in Veterinary Practice, ed 2.
Philadelphia, WB Saunders Co, 1984, pp 160–179.
2. Morgan JP, Silverman S: Techniques of Veterinary Radiography, ed
5. Davis, CA, Veterinary Radiology Associates, 1993, pp
162–167.
3. Rendano VT: Canine hip dysplasia evaluation. Vet Radiol Ultra-
sound 26:170–186, 1985.
4. Smith GK, Biery DN, Gregor TP: New concepts of coxofemoral
joint stability and the development of a clinical stress-radi-
ographic method for quantitating hip joint laxity in the dog.
JAVMA 196:59–70, 1990.
5. Smith GK, Gregor TP, Rhodes WH, et al: Coxofemoral joint
laxity from distraction radiography and its contemporaneous
and prospective correlation with laxity, subjective score, and evi-
dence of degenerative joint disease from conventional hip-ex-
tended radiography in dogs. Am J Vet Res 54:1021–1042, 1993.
6. Fluckiger MA, Friedrich GA, Binder H: A radiographic stress
technique for evaluation of coxofemoral joint laxity in dogs. Vet
Surg 28:1–9, 1999.
7. Slocum B, Devine TM: Dorsal acetabular rim radiographic view
for evaluation of the canine hip. JAAHA 26:289–296, 1990.
8. Rendano VT, Quick CB, Allen GS, et al: Radiographic evalua-
Figure 8—Bending force stress radiographic view of the lateral tion of femoral head and neck fractures: The value of the flexed
ventrodorsal and oblique projections in diagnosis. JAAHA
portion of the talocrural joint (arrow). Note the abnormal
16:485–491, 1980.
widening of the medial portion of the joint space. This is
9. Farrow CS: Stress radiography: Applications in small animal
consistent with ligamentous instability.
practice. JAVMA 181:777–784, 1982.
878 Small Animal/Exotics Compendium October 2001

10. de Rooster H, van Bree H: Radiographic measurement of cran- b. ventrodorsal hyperextended

iocaudal instability in stifle joints of clinically normal dogs and c. ventrodorsal flexed
dogs with injury of a cranial cruciate ligament. Am J Vet Res
60:1567–1570, 1999. d. lateral oblique
11. Harari JS, Person M, Berardi C: Fractures of the patella in dogs
and cats. Compend Contin Educ Pract Vet 12(11):1557–1563, 3. If joint laxity is demonstrated on the medial side of the
1990. stifle during a physical examination, which radi-
12. Vasseur PB: Textbook of Small Animal Surgery, ed 2. Philadel- ographic view would best be able to diagnose ligamen-
phia, WB Saunders Co, 1993, pp 1857–1858.
tous instability?
13. Boudrieau RJ, Dee JF, Dee LG: Treatment of central tarsal bone
fractures in the racing greyhound. JAVMA 184:1492–1500,
a. caudocranial oblique
1984. b. mediolateral hyperextended
14. Anderson MA, Constantinescu GM, Dee LG, et al: Fractures c. caudocranial with bending force applied laterally
and dislocations of the racing greyhound—Part II. Compend d. caudocranial with bending force applied medially
Contin Educ Pract Vet 17(7):899–909, 1995.
15. Peirmattei DL, Flo GL: Handbook of Small Animal Orthopedics 4. Which additional radiographic view may demonstrate
and Fracture Repair, ed 3. Philadelphia, WB Saunders Co, 1997,
pp 636–641. evidence of hip dysplasia or trauma associated with the
16. Carlisle CH, Robins GM, Reynolds KM: Radiographic signs of acetabular rim?
osteochondritis dissecans of the lateral ridge of the trochlea tali a. flexed ventrodorsal
in the dog. J Small Anim Pract 31:280–286, 1990. b. dorsal acetabular rim
17. Carlisle CH, Reynolds KM: Radiographic anatomy of the tar- c. extended ventrodorsal
socrural joint of the dog. J Small Anim Pract 31:273–279, 1990.
d. ventrodorsal oblique
18. Smith MM, Vasseur PB, Morgan JP: Clinical evaluation of dogs
after surgical and nonsurgical management of osteochondritis
dissecans of the talus. JAVMA 187:31–35, 1985. 5. Which view allows the best visualization of the
19. Wisner ER, Berry CR, Morgan JP, et al: Osteochondrosis of the trochlear ridges of the talus?
lateral trochlear ridge of the talus in seven rottweiler dogs. Vet a. flexed dorsoplantar skyline
Surg 19:435–439, 1990.
b. plantarodorsal hyperextended
20. Alexander JW, Richardson DC, Selcer BA: Osteochondritis dis-
c. mediolateral flexed
secans of the elbow, stifle, and hock—A review. JAAHA 17:51–
56, 1981. d. hyperextended dorsoplantar skyline
21. Miyabayashi T, Biller DS, Manley PA, et al: Use of a flexed dor-
soplantar radiographic view of the talocrural joint to evaluate 6. The skyline view of the patella will allow visualization
lameness in two dogs. JAVMA 199:598–600, 1991. of which structure?
a. cranial surface
b. articular surface
ARTICLE #2 CE TEST

CE
The article you have read qualifies for 1.5 con- c. femoral trochlear ridges
tact hours of Continuing Education Credit from d. a and b
the Auburn University College of Veterinary Med- e. all of the above
icine. Choose the best answer to each of the follow-
ing questions; then mark your answers on the 7. Which view allows the best visualization of a central
postage-paid envelope inserted in Compendium. tarsal bone fracture and luxation?
a. dorsolateral to plantaromedial oblique
1. Which radiographic view for hip laxity may be used b. mediolateral flexed
without the requirement of a specially certified veteri- c. dorsoplantar
narian? d. dorsomedial to plantarolateral oblique
a. extended ventrodorsal
b. stress ventrodorsal 8. What osseous structure is well visualized with the dor-
c. dorsal acetabular rim
soplantar skyline view of the tarsal joint?
d. flexed ventrodorsal
e. a and b a. medial malleolus
b. trochlear ridges of the talus
2. Which additional radiographic view may be indicated c. sustentaculum tali
to better visualize a femoral neck fracture? d. a and b
a. ventrodorsal oblique e. all of the above
(continues on page 886)
886 Small Animal/Exotics Compendium October 2001

Radiographic Views (continued from page 878)

9. Why can osseous lesions be better visualized with

additional views?
a. less superimposition of osseous structures
b. x-ray beam is oriented tangential to the lesion
c. less superimposition of soft tissue structures
d. a and b
e. a, b, and c

10. Which additional view may not be helpful in demon-

strating osteochondrosis of the tarsal joint?
a. hyperextended mediolateral
b. dorsoplantar flexed skyline
c. dorsoplantar oblique
d. hyperflexed mediolateral
e. all of the above