Splint Bone & Proximal Sesamoid Bone Fractures

Question 1

What bones are referred to as the splint bones?

Answer 1

MC/MT II and IV

Question 2

T/F: MT IV has minimal articulation and weight transfer with the 4th tarsal bone

Answer 2

TRUE

Question 3

What are causes of splint bone fractures?

Answer 3

Hyperextension of fetlock (closed)
External trauma (open)

Question 4

T/F: Many splint bone fractures are treated successfully with rest alone

Answer 4

TRUE

Question 5

What may lead to persistent lameness post splint bone fracture?

Answer 5

Suspensory desmitis

Question 6

What is the most common splint bone fracture?

Answer 6

Fractured splint bone(distal 1/3)

Question 7

What is the surgical treatment for a splint bone fracture?

Answer 7

Segmental ostectomy

Question 8

What is the rule of fractions when removing a portion of the splint bone during a segmental ostectomy?

Answer 8

Don’t remove more than distal 2/3 of splint bone(except MT IV)
If more than this is removed than you will need internal fixation

Question 9

If you are providing internal fixation when correcting a splint bone fracture, which bone shouldn’t be involved?

Answer 9

MC III

This will lead to persistent lameness due to micromovement between the bones

Question 10

If you have to incoorporate MCIII, how many months post-op do you have to go back to surgery to remove the plate?

Answer 10

3-4 months post-op

Question 11

What is the common age and location of splint exostosis/proliferative periostitis?

Answer 11

Young horses MCII (medial aspect)

Question 12

What is the most common causeof splint exostosis?

Answer 12

Direct trauma

Question 13

What are CS of splint exostosis?

Answer 13

Firm swelling at the site (warm and painful)

Question 14

What is the conservative treatment for splint exostosis?

Answer 14

NSAIDs, local DMSO or corticosteroids

Question 15

What is deep to the splint bone?

Answer 15

Neurovascular bundle

Question 16

Where are three places to get the pulse on a horse?

Answer 16

Facial artery
Transverse facial artery
Dorsal metatarsal artery (runs between lateral splint bone MT IV and MTIII)

Question 17

What type of fracture can be prevented by the gait & speed training?

Answer 17

Dorsal cortical fracture of MCIII

Question 18

What is the surgical treatment for a dorsal cortical fracture of MCIII?

Answer 18

Osteostixis

Creates holes around site and brings mesenchymal cells to surface

Question 19

What direction should you drill when performing osteostixis?

Answer 19

Drill towards the medullary canal (this is where your growth factors come from)

Question 20

What are the six types of proximal sesamoid bone fractures?

Answer 20

Apical (most common)
Mid-body
Basal
Abaxial
Sagittal
Comminuted

Question 21

What is a common cause of proximal sesamoid fractures>

Answer 21

Excessive tension from suspensory ligament (commonly seen in racing breeds)

Question 22

What does treatment of proximal sesamoid fractures depend on?

Answer 22

Size of the fragment

Question 23

What does a mid-body sesamoid fracture require to treat?

Answer 23

Internal fixation (lag screw or circumferential cerclage wire)

Question 24

T/F: Screw fixation with arthroscopic guidance is superior to wire fixation

Answer 24

TRUE

Question 25

What rads should be taken to visualize an abaxial sesamoid fracture?

Answer 25

60 degree skyline oblique

Question 26

Which fracture involves origin of all distal sesamoidean ligaments?

Answer 26

Basilar sesamoid fracture

Question 27

What is the prognosis of a basilar sesamoid fracture?

Answer 27

Poor