Exam 2: Splint Bone and Proximal Sesamoid Bone Fractures Flashcards
Metacarpus/Metatarsus 2 and 4
are better known as
Splint bones
Most splint bones articulate with carpal and tarsal bones,
except for ______,
which has minimal articulation and weight transfer
with the 4th tarsal bone
MT4
What are the causes of closed splint bone fractures?
Hyperextension of the fetlock
What are the causes of open splint bone fractures?
External trauma
T/F:
Many splint bone fractures can be treated
successfully with rest alone
TRUE
_______ desmitis (inflammation of the ligament)
can be related to splint bone fractures and
can result in PERSISTENT LAMENESS
Suspensory
Why is it important to evaluate splint bone fractures
using serial ULTRASOUND?
Because suspensory desmitis can be related to the fracture
and cause persistent lameness
What is the most common location for
a splint bone fracture?
DISTAL 1/3 of the bone
How are splint bone fractures diagnosed?
RADS + U/S
What type of radiograph is required for
dx of splint bone fracture?
DLpmo
What type of surgical procedure is indicated for
select cases of splint bone fracture?
Segmental Ostectomy
removal of fracture fragments and residual distal splint bone
During segmental ostectomy,
DO NOT REMOVE MORE THAN _________
of the DISTAL splint bone
2/3
Fracture of this splint bone is the
exception to the rule, and more than 2/3 of the distal splint
bone can be removed via segmental ostectomy
MT4
If you must remove greater than 2/3 of the distal splint bone,
_________ of the proximal fragment is necessary
internal fixation
If plating a splint bone fracture,
DO NOT ENGAGE ________,
because there is micromovement between them
and this will result in persistent lameness
MC3
Must remove plate within 3 months if MC3 is engaged
This radiographic view is used to diagnose
splint bone fractures
DLpmo
What’s your dx?
Splint bone fracture
A a benign outgrowth of cartilaginous tissue on a bone
is known as
exotosis
Splint exotosis is most common in
_____ horses, and usually affects
this particular splint bone
Splint exotosis is most common in
young horses, and usually affects
MC2
Splint exotosis usually occurs on the
______ aspect of the limb
medial
What can cause the condition seen on this radiograph?
Splint exotosis:
Direct trauma
Ligament inflammation (desmitis)
What are your conservative treatment options for
treatment of splint exotosis/proliferative periostitis?
Rest
NSAIDs
Local DMSO
Infiltration with CORTICOSTEROIDS
En bloc removal is the surgical option for treatment of
splint exotosis/proliferative periostitis.
The most important aspect of post-op treatment is
EXCELLENT bandaging
or may recur
For en bloc removal of splint exotosis/proliferative periostitis,
a tourniquet is placed proximally,
and an incision is made directly over the splint bone.
Why must you be careful not to move off of the
splint bone?
Because NEUROVASCULAR bundle is deep to it
What 3 places are used to find a pulse in a horse?
Facial artery
Transverse Facial artery
Dorsal Metatarsal artery
Describe the location of the
dorsal metatarsal artery
Runs between the lateral splint bone
MT4 and MT3
What is your diagnosis?
Dorsal cortical fracture of MC3
Dorsal cortical fractures of MC3 are categorized as
_________ fractures
stress
Young horses with bucked shins are at risk for
this type of fracture
Dorsal cortical fracture of MC3
How do you prevent bucked shins
which can help to avoid dorsal cortical stress fractures
of MC3?
Gait and Speed Training
Less long distance galloping
How are dorsal cortical stress fractures of MC3
treated medically?
rest, NSAIDs, exercise programs
How are dorsal cortical stress fractures of MC3
treated surgically?
Osteostixis (alone or in combo with a screw)
BEST is combination with screw removal at 60 days
What is the mechanism of action
of osteostixis in the treatment of
dorsal cortical stress fractures of MC3?
Creates holes to bring mesenchymal cells
from the medullary canal to the surface
For osteostixis, you must drill _______ to
the fracture and place a single
_________ 22mm positional screw
For osteostixis, you must drill perpendicular to
the fracture and place a single
unicortical 22mm positional screw
6 - 8 osteostixis holes are drilled _____mm apart
and drilled towards the MEDULLARY CANAL
10 mm
What is a saucer fracture?
A type of bucked shin fracture in which a
saucer shaped piece of bone is separated from the front of
the cannon bone (MC3)
What is this radiograph showing?
Osteostixis and screw placement
for treatment of a dorsal cortical stress fracture of MC3
Classify the proximal sesamoid bone fracture:
What is 1?
Apical
2
Classify the proximal sesamoid bone fracture:
Mid-Body
3
Classify the proximal sesamoid bone fracture:
Basal
4
Classify the proximal sesamoid bone fracture:
Abaxial
5
Classify the proximal sesamoid bone fracture:
Sagittal (Axial)
6
Classify the proximal sesamoid bone fracture:
Comminuted
What is the most common type of proximal
sesamoid bone fracture?
1: APICAL
What are the causes of
proximal sesamoid bone fracture?
Excessive suspensory ligament tension
Trauma
proximal sesamoid bone fractures
are most commonly seen in these types of horses
Racing breeds
How are Apical sesamoid fractures treated?
What is the prognosis?
Arthroscopic removal
Prognosis = GOOD
How are mid-body sesamoid fractures treated?
What is the prognosis?
Internal fixation with lag screw (best)
or cerclage wire
+
CAST
How are Abaxial (#4) sesamoid fractures treated?
What is the prognosis?
Intra-articular = Arthroscopic removal
Extra-articular = Conservative management
Prognosis = Fair to Good
This type of sesamoid bone fracture can be easily
missed on radiographs
Abaxial
This type of radiograph is required in order
to see if an abaxial sesamoid fracture is intra-articular
60 degree skyline oblique
This type of sesamoid fracture has a POOR prognosis
because it is the origin of all distal
sesamoidean ligaments
BASAL (#3)
A basal sesamoid fracture is also known as
BUST UP
There is an inverse relationship between
__________ length and return to racing
in regards to basal sesamoid fractures
dorsopalmar
