26.5.1: Emergency fractures in the horse Flashcards
How do we classify fractures?
- Location: which bone involved, and where (metaphysis, diaphysis, epiphysis)
- Structures involved i.e. articular or non-articular
- Contamination i.e. open or closed. Horses generally do not do well with open fractures
- Extent of damage: complete/ incomplete, simple/ comminuted
- Size of fragment: chip vs slab vs shaft fracture
- Fracture configuration: transverse, oblique, spiral, avulsion, growth plate
- Displacement, fracture fragments, margins
Describe this fracture
- Simple transverse fracture of the accessory carpal bone
- Non articular and no evidence of external communication
- Moderate displacement with at least two fragments and irregular, poorly defined margins
- No joint effusion or swelling on the palmar aspect of the limb
- This is a chronic fracture; it is hard to stabilise and any screws (internal fixation) would probably fracture it further and maybe enter the joint
–> Recommend ultrasound to check carpal sheath and flexor structures, then conservative management. Guarded prognosis for return to work
Describe this fracture
- Complete comminuted fracture of the olecranon
- Communicates with elbow joint; no evidence of external communication
- Minimal displacement, multiple fragments, butterfly configuration with sharply defined margins
- This is an acute fracture. Articular involvement and pull of the triceps means internal fixation recommended.
–> Good prognosis with internal fixation depending on repair and anaesthetic recovery outcomes. These can do well because the ulna isn’t weight-bearing
What is the most common cause of fractures in horses?
a) trauma
b) developmental e.g. OCD
c) pathological e.g. secondary to neoplasia
a) trauma
May be acute e.g. kick, fall
May be chronic repetitive trauma e.g. stress fractures in racehorses
What are the typical sites for fractures caused by kick injuries?
- Splint bones
- Stifle bones e.g. tibia, patella
- Olecranon
- Head
Describe this fracture and what might have caused it
- Fracture to the lateral splint bone and also part of the third metacarpal / metatarsal bone
- Has an articular component so this fracture is unstable
- Mild displacement
- Likely caused by a kick
Describe this fracture and what might have caused it
- Fracture to the olecranon
- Articular component so unstable
- Minimal displacement
- Likely caused by a kick
What are the typical sites for fractures caused by trauma or falls?
- Head
- Vertebrae
- Long bones (femoral or cannon fractures during anaesthetic recovery especially)
- Joints during competitions (e.g. patella due to hitting fence)
What are the typical sites for fractures caused by repetitive wear and tear?
- Distal phalangeal (pedal) bone
- Middle phalangeal (pastern) bone
- Distal sesamoidean (navicular) bone
Describe this fracture and what might have caused it
- Complete fracture of the navicular bone
- Likely caused by repetitive wear and tear
Where are the most common sites for stress fractures in racehorses?
Can happen anywhere, but most common:
* Carpal bones (radius, radiocurpal, third carpal)
* Third metacarpal bone
* Middle phalangeal (pastern) bone
* Proximal sesamoid bones
* Radius
* Tibia
* Pelvis
* Vertebrae
Clinical signs of an acute, severe, or displaced fracture
- Obvious conformational abnormalities
- Severe lameness
- Pain and crepitus at the fracture site
Clinical signs of non-displaced fractures, including stress fractures, and small chip fractures
- Minimal lameness and localising signs
- Non-displaced stress fractures may present as acute onset lameness following exercise which resolves over a few days
Non-displaced, repairable fractures can progress to catastrophic irreperable fractures if not recognised and treated appropriately
Clinical signs of articular fractures
- Articular fractures normally have joint effusions
Major red flags for fractures in the history / presentation
🚩History of trauma e.g. kick or fall
🚩 Acute onset severe lameness
🚩 Acute onset joint effusion
🚩 Heat, pain, swelling, and palpable crepitus
True/false: a horse with a splint bone fracture may be able to walk normally.
True
because the splint bone is non-weightbearing
What radiographic view is shown here and what will it highlight?
DLPMO
This will highlight the dorsmedial and palmarolateral aspects
What do the “hot spots” on this gamma scintigraphy image indicate?
These are areas of active bone remodelling
What is your primary differential in this case? How could you confirm this?
Foot abscess
* Heat, bounding digital pulses, and use of hoof testers would localise to the foot and increase suspicion of foot abscess
* Fracture is usually associated with history of trauma
What must you do at first examination of a suspected fracture to avoid complications further down the line?
The horse pictured had a salvageable fracture when it went to transport, but this wasn’t splinted, so the horse was weight-bearing repeatedly and then thus happened.
Principles of repair of articular fractures
How would you repair this fracture?
Remove the fragment (it is small so this is doable)
How would you repair this fracture?
Internal fixation - this fragment is large and needs to be screwed on
True/false: if a fracture can be repaired, any soft tissue injury is also likely to be fixable.
False
When the toe is up and the fetlock has dropped, as in this picture, which structures have been damaged?
- Toe up = damage to the deep digital flexor tendon
- Collapsed fetlock = damage to the suspensory ligament
- In this case, although the sesamoid fractures are fixable, the soft tissue injuries are not, therefore euthanasia is required
When should you consider euthanasia?
What is the correct term for this radiographic view?
a) dorsolateral palmaromedial oblique
b) flexed dorsopalmar
c) flexed lateromedial
d) dorsomedial palmarolateral oblique
e) skyline oblique
c) flexed lateromedial
What is the correct description for this fracture?
a) closed, comminuted, non-articular
b) closed, simple, non-articular
c) closed, comminuted, articular
d) open, simple, non-articular
e) open, comminuted, articular
f) open, comminuted, non-articular
e) open, comminuted, articular
