Splint Bone/ Proximal Sesamoid Bone Fractures

Question 1

Splint Bone Anatomy:

1. Articulate with…
2. Provides (axial/abaxial) support

Answer 1

1. carpal and tarsal bones

2. axial

Question 2

Which splint bone has minimal articulation and weight transfer with the 4th tarsal bone?

Answer 2

MT IV

Question 3

Causes of Splint Bone Fractures:
1.
2.

Answer 3

1. Hyperextension of fetlock = closed

2. External trauma = open

Question 4

T/F: Splint bone fractures can be treated successfully with rest alone

Answer 4

T

Question 5

Splint bone fractures:

Suspensory _____ may cause persistent lameness

Answer 5

desmitis

Question 6

Treatment options for splint bone fractures:

1.
2.
3.
4.
5. Distal fractures? 
6. Proximal fractures

Answer 6

1. Conservative wound management
2. segmental ostectomy
3. removal of distal portion
4. ORIF
5. distal fractures = surgical removal
6. Proximal fractures = wound management and removal of loose segments + internal fixation

Question 7

Surgical treatment of splint bone fractures:

1. When removing residual distal splint bone, do not remove more than …..
2. If you do remove more than that, you must…
3. Exception?

Answer 7

1. the distal 2/3 of the splint bone
2. Use internal fixation for proximal fragment
3. except MT IV

Question 8

Internal fixation of fractured splint bones:

1. Do not engage ____. Why? If you do it by accident?

Answer 8

1.MC III. Will cause persistent lameness. Remove the plate 3-4 months post op.

Question 9

Splint Exostosis:

Affects (old/young) horses? Which bone?

Answer 9

young horses on MC II

Question 10

2 main causes of splint exostosis

Answer 10

direct trauma or ligamentous inflam

Question 11

Using radiographs to diagnosis splint exostosis:

Start with ____ view, than use ___ view to look for hidden splints

Answer 11

oblique

DP

Question 12

Exostosis Treatment:

Conservative treatment:
1.
2.

Answer 12

1. Rest + NSAIDs

2. Local DMSO or infiltration with corticosteroids

Question 13

Exostosis Treatment: Surgical

1. Sx?
2. Post-op?

Answer 13

1. Linear incision over site with en bloc removal

2. Excellent bandaging required post-op

Question 14

Surgical Intervention of Exostosis

1. Incise where?
2. Be sure to avoid…

Answer 14

1. directly over the splint bone from the middle of the splint bone to the button
2. muscles, neurovascular structures

Question 15

What structure do you have to really be careful to avoid during surgical intervention of exostosis?

Answer 15

Dorsal metatarsal artery because it runs between the lateral splint bone (MT IV) and MTIII.

Question 16

Bucked Shins aka

Answer 16

dorsal cortical fractures

Question 17

Bucked Shins/Dorsal Cortical Fractures:
Stress fractures:

Usually affects what animals?

Answer 17

3 year olds with bucked shins as 2 year olds

Question 18

Bucked Shins/Dorsal Cortical Fractures:

Describe the fracture appearance/location

Answer 18

A fissure extending 60% through dorsal cortex at 30 degree angle proximally and disappears.

May curve back to dorsal cortex.

Question 19

Prevention of bucked shins?

Answer 19

Allocate more training efforts to regular short distance breezing and less long distance galloping

Question 20

Medical Treatment options for Bucked Shins:

1. Only consider medical if in what regions?
2.
3.
4.
5.

Answer 20

1. Distal/proximal metaphyseal regions
2. Rest
3. NSAIDs
4. Reduced exercise program
5. Radiographic monitoring

Question 21

Surgical treatment of Bucked Shins:

1.
2. Best results with:

Answer 21

1. Osteostixis

2. Osteostixis in combo with screw, removing screw at 60 days

Question 22

Describe surgical treatment of bucked shins via osteostixis:

Answer 22

Use staples pre-op to help ID the fracture during surgery
Drill perpendicular to fracture
Use radiographic guidance during sx
Place single unicortical positional screw
6-8 osteostixis holes drilled 10 mm apart, making sure to drill TOWARDS medullary canal

Question 23

T/F: The chances that a horse with bucked shins/saucer fractures will return to racing are slim

Answer 23

F, chances are good.

Question 24

Causes of Proximal Sesamoid Bone Fractures:
1.
2.
3.

Answer 24

1. Excessive tension from suspensory ligament
2. Trauma
3. Racing breeds

Question 25

What kind of proximal sesamois bone fracture is most common?

Answer 25

Apical fracture

Question 26

Treatment of Apical Sesamoid Fracture: 1. If small? 2. if large?

Answer 26

1. Arthroscopic removal | 2. internal fixation

Question 27

Apical sesamoid bone fracture: prognosis?

Answer 27

Good - usually don't cause significant suspensory dz

Question 28

Midbody Sesamoid bone fracture Tx: 1. Requires _______. Options?

Answer 28

1. Internal fixation Lag screw or circumferential cerclage wire. Screw fixation in lag fasion best for TB to RTR. Cerclage reserved for SB.

Question 29

Best way to diagnose abaxial sesamoid bone fracture?

Answer 29

Radiographs 60 degrees skyline view to see if articular

Question 30

Abaxial sesamoid bone fracture treatment: 1. If intra-articular? 2. If extra-articular? 3. Prognosis?

Answer 30

1. Arthroscopic removal 2. conservative management 3. fair to good

Question 31

Basilar sesamoid bone fracture: 1. Poor prognosis because...

Answer 31

1. It involves origin of all distal sesamoidean ligaments and lag screw fixation is challenging