Radiology Packet 43
Equine Phalanges
3 yr old STDB Gelding
• HX = presented for an acute onset of lameness in the left
fore that occurred immediately after racing, the horse is
sensitive to hoof testers in the left fore foot
3 yr old STDB Gelding
3 yr old STDB Gelding
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•
RF
– In the DP view there is a linear lucency in the lateral aspect of P3, this
line is approximately parallel to midline and is oriented in a different
direction than the normal vascular channels.
– The DLPMO view provides better visualization of the lucent line.
– This line can be seen extending into the distal inter-phalangeal joint.
– The opaque material seen along the medial surface in the DP and
DLPMO views is debris on the surface of the hoof.
RD
– Articular fracture of the lateral aspect of P3 (Type II)
13 yr old Appaloosa Gelding
“Joker”
• HX = history of right forelimb lameness and a noticeably
large pastern
13 yr old Appaloosa Gelding
“Joker”
13 yr old Appaloosa Gelding
“Joker”
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RF
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Marked narrowing of the proximal interphalangeal joint.
Marked osteophyte formation around the dorsal, medial, and lateral margins of P1-2,
involving the distal periarticular margins of P1 and the proximal margins of P2.
The osteophytes extend well beyond the articular margins, to include the distal half of P1 and
the proximal half of P2.
Enthesophytes are noted along the palmar surface of mid P1, the site of distal suspensory
ligamentous attachment.
On the DP radiograph note the very mottled bone opacity of distal P1 due to the large
amount of new bone.
RD
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Severe degenerative joint disease of the right front proximal interphalangeal joint, known as
high ringbone
Since the bony reaction extends well beyond the articular margins and includes mid P2, nonarticular ringbone is also present
2 yr old STDB Colt
• HX = grade 3 of 4 lame in the right hindlimb
2 yr old STDB Colt
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RF
– There is a subchondral lucency in the proximomedial aspect of the middle
phalanx.
– The lucent area is irregularly marginated and surrounded by sclerotic bone.
– In the lateral view the lucent area is not seen as a distinct structure but there is
an appearance of mixed opacity in the dorsoproximal middle phalanx.
– Careful evaluation (hotlight) shows an irregular periosteal response on the dorsal
aspect of the second phalanx which seems to be located at the distal margin of
the lucent lesion.
RD
– Subchondral bone cyst of the proximal middle phalanx
Next
– Surgical curettage could be considered, however with a cyst in this location,
secondary osteoarthritis will likely occur and the prognosis for soundness is fairly
poor.
4 yr old Grade Gelding
“Bobby”
• HX = presented for evaluation of bilateral forelimb
lameness
4 yr old Grade Gelding
“Bobby”
•
RF
– The osseous structures of the right forelimb (left film) are normal in appearance.
– In the left forelimb there is osteophyte formation at the extensor process of the
third phalanx (right film).
•
RD
– Degenerative joint disease (osteoarthritis) of the distal interphalangeal joint of the
left forelimb (low ringbone)
3 yr old Arabian Colt
• HX = presented for evaluation of a left forefoot lameness
that has been going on for three weeks
3 yr old Arabian Colt
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RF
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There is a large round lucency located centrally within the distal phalanx.
A sclerotic margin surrounds the area of lucency.
In the lateral view remodeling of the dorsoproximal third phalanx is evident.
This has resulted in change in shape of the extensor process and narrowing of
the distal interphalangeal joint dorsally.
RD
– Subchondral bone cyst of the third phalanx
Next
– Surgical curettage
1 yr old Belgian Filly
“Candy”
• HX = the filly is grade 4 of 5 lame in the left hindlimb and
has been for one month
1 yr old Belgian Filly
“Candy”
•
RF
– There is a sibchondral lucency in the distomedial aspect of the proximal phalanx.
– A rim of sclerotic bone surrounds the lucency.
– In the DP view the lucency appears to extend to the articular surface of the bone.
•
RD
– Subchondral bone cyst of the distal proximal phalanx
•
Next
– Surgical curretage, however with a cyst in this location, secondary osteoarthritis
will likely occur and the prognosis for soundness is fairly poor.
6 yr old Hanoverian Stallion
“Twol”
• HX = acute RF lameness isolated to the foot
6 yr old Hanoverian Stallion
“Twol”
6 yr old Hanoverian Stallion
“Twol”
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RF
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A large, wide radiolucent line is present in the medial quarter/heel of P3 on the DP view.
Lucent curvilinear shadow seen on the lateral view from the edge of P3 coursing to near the
navicular bone.
The DMPLO view nicely shows the linear lucency, extending from the solar margin to the
very edge of the joint.
A large, ovoid osseous bony structure is present associated with the extensor process of P3
on the lateral view.
Mild periarticular osteophyte formation on the dorsoproximal surface of P2 is present.
RD
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Non-articular Type I fracture of the medial wing of right front P3
Type IV P3 fracture, an extensor process fracture
Mild degenerative joint disease of the P1-2 joint
3 yr old STDB Colt
• HX = acutely non-weight bearing lame in left hindlimb at
the end of a race, a cast was applied to the limb prior to
transporting the horse
3 yr old STDB Colt
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RF
– Fracture lines are seen extending from the sagittal groove of the proximal
phalanx and coursing in a disto-lateral direction.
– The fracture exits at the plantaro-lateral aspect of the articular surface of the
bone.
– The fracture is minimally displaced.
– In the DP view 2 fracture lines are visible in the proximal portion of P1, this is
actually a single fracture line with 2 surfaces (dorsal and plantar), because the xray beam is not exactly aligned with the fracture, both surfaces are visible.
– Cast materials surrounds the limb making evaluation of the soft tissues difficult.
RD
– Non-displaced sagittal fracture of the proximal phalanx extending from the
articular surface of the metatarsophalangeal joint to the articular surface of the
proximal interphalangeal joint
9 yr old Canadian Hunter Mare
“Jessica”
• HX = foot abscess
9 yr old Canadian Hunter Mare
“Jessica”
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RF
– There is a discrete well-circumscribed lucent defect in the lateral margin
of the third phalanx.
– The bone adjacent to the defect is slightly irregular in appearance.
– The areas of increased opacity associated with the soft tissues of the
hoof are debris on the solar surface.
RD
– Osteomyelitis of the third phalanx
6 mo old Belgian Filly
“Imperial Julie”
• HX = swollen left hind fetlock
6 mo old Belgian Filly
“Imperial Julie”
6 mo old Belgian Filly
“Imperial Julie”
•
RF
– Several various sized osteochondral fragments associated with the proximal midsagittal ridge of distal MT3.
– The sagittal ridge is irregular here, indicating a bed from which the fragments
arose.
– Soft tissue swelling of the fetlock joint is noted.
•
RD
– OCD of the sagittal ridge of left metatarsal 3
•
Next
– Radiographic examination of the remaining fetlocks, as well as the tarsi.
5 yr old STDB Gelding
“Blu Meadow Chance”
• HX = acute RF lameness isolated to the foot, two views
were taken at the time of injury, plus a DP view 6 months
later
5 yr old STDB Gelding
“Blu Meadow Chance”
5 yr old STDB Gelding
“Blu Meadow Chance”
•
RF
– The first films show the presence of a linear lucency traversing from the solar
margin of P3 laterally toward the corner of the distal interphalangeal joint.
– The recheck film shows this lucent line is still quite evident.
•
RD
– Type II RF P3 fracture
– The follow up films show a fracture line, however P3 fractures often heal by
fibrous, not osseous union, so it may be as healed as it will ever be and if the
horse is sound nothing further needs to be done
10 yr old Morgan Mare
“Emma”
• HX = The horse fell in a ditch on a trail ride, after the
accident she was non-weight-bearing lame on the right
hind for 3 days. The lameness improved to a grade 4 of
5 but has gotten no better.
10 yr old Morgan Mare
“Emma”
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•
RF
– There is a fracture extending from the dorsomedial margin to the
extensor process of the third phalanx.
– In the lateral view there is osteophyte formation on the extensor process
of the third phalanx.
– Irregular periosteal response is present on the dorsal margin of the
second phalanx.
RD
– Fracture of the third phalanx (Type III)
– Degenerative joint disease of the distal interphalangeal joint