Splint Bone and Proximal Sesamoid Bone Fractures

Question 1

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

Answer 1

MT4

Question 2

Provide axial support to carpus and tarsus

Answer 2

Splint bones

Question 3

Is the accessory carpal bone medial or lateral?

Answer 3

Lateral

Question 4

Is MT4 medial or lateral?

Answer 4

Lateral

Question 5

What causes closed splint bone fractures?

Answer 5

Hyperextension of the fetlock

Question 6

What causes open splint bone fractures?

Answer 6

External trauma

Question 7

What may cause persistent lameness assoc. w/splint bone fractures?

Answer 7

Suspensory desmitis

Question 8

How do you treat a proximal splint bone fracture?

Answer 8

Remove loose fragments and internal fixation

Question 9

How much of a residual distal splint bone can you remove?

Answer 9

Less than 2/3

Question 10

If you remove more than 2/3 of the distal splint bone, what other stabilization do you need?

Answer 10

Internal fixation of proximal fragment

Question 11

What soft tissue is most commonly injured along with splint bones?

Answer 11

Suspensory ligament

Question 12

When plating a splint bone fracture, why should you not engage MC3 with the plate?

Answer 12

Micomotion will cause persistent lameness

Question 13

If you do have to engage MC3 with a plate, when must the plate be removed?

Answer 13

3-4mo later

Question 14

Occurs in MC2 of young horses d/t direct trauma or ligamenous inflammation

Answer 14

Splint exostosis

Question 15

What is the most common cause of splint exostosis?

Answer 15

One forelimb hits the inside of the other leg

Question 16

How can you reduce inflammation at a splint exostosis site?

Answer 16

Local DMSO, infiltration w/steroids

Question 17

How do you surgically treat exostosis?

Answer 17

Linear incision over site w/en bloc removal

Question 18

There are no muscles or neurovascular structures directly over the splint bone between which landmarks?

Answer 18

Middle of splint bone to button

Question 19

What are the 3 places to get a pulse on a horse?

Answer 19

Facial, transverse facial, and dorsal metatarsal artery

Question 20

Where does the dorsal metatarsal artery run?

Answer 20

Between MT3 and MT4

Question 21

Caused by bucked shins, dorsal metacarpal disease, or stress fractures

Answer 21

Periostitis and fracture of dorsal MC

Question 22

Usually occurs in 3yr olds w/bucked shins as 2yr olds

Answer 22

Stress fractures

Question 23

How can you prevent bucked shins with exercise modification?

Answer 23

Regular short distance breezing and less long distance galloping

Question 24

What is the best treatment for a stress fracture?

Answer 24

Osteostixis w/screw

Question 25

When should an osteostixis screw be removed?

Answer 25

60d post-op

Question 26

How far apart are osteostixis holes?

Answer 26

10mm

Question 27

What is the px for bucked shins for return to racing?

Answer 27

Good

Question 28

What are the 6 types of proximal sesamoid bone fractures?

Answer 28

1: apical 2: mid-body 3: basal 4: abaxial 5: sagittal (axial) 6: comminuted

Question 29

What causes a proximal sesamoid bone fracture?

Answer 29

Excessive tension from SL, trauma

Question 30

What type of proximal sesamoid bone fracture is the most common?

Answer 30

Apical

Question 31

What breeds are most commonly diagnosed w/proximal sesamoid bone fractures?

Answer 31

Racing breeds

Question 32

How do you treat an apical (type 1) sesamoid fracture?

Answer 32

Arthroscopic removal or internal fixation if large

Question 33

How do you treat a mid-body (type 2) sesamoid fracture?

Answer 33

Internal fixation w/lag screw or circumferential cerclage wire

Question 34

Which breeds is cerclage wire used for mid-body sesamoid fractures?

Answer 34

Standardbred

Question 35

Which internal fixation method is more superior for mid-body sesamoid fracture treatment?

Answer 35

Arthroscopic screw fixation

Question 36

What radiographic view do you need for dx of abaxial (type 4) sesamoid fractures?

Answer 36

60* skyline view

Question 37

How do you treat an abaxial sesamoid fracture?

Answer 37

Athroscopic removal if intra-articular, otherwise conservative management

Question 38

Which type of sesamoid fracture involves origin of all distal sesamoidean ligaments and therefore carries a poor prognosis

Answer 38

Basilar (type 3) sesamoid fractures