Sequestrum

Question 1

A necrotic piece of bone that is separated from viable parent bone by infection, inflammation or both is termed __________

Answer 1

Sequestrum​

Question 2

__________ is the number one reason for sequestrum

Answer 2

Non-healing wound

Sequestrum is acting like a foreign body (no blood supply, so it can’t be reabsorbed)

Question 3

Most equine bone sequestrums are located on the:

Answer 3

Metacarpal or metatarsal bones

• The #1 location is the cannon bone. These are also the areas where we see fractures and osteomyelitis most often.
  
  • In these areas, there is less soft tissue protection.

Question 4

Radiographic evidence of a sequestrum might not be apparent for _____ days

Answer 4

10-14 days​

Question 5

Regarding sequestrum formation, periosteal trauma can produce ischemic necrosis of underlying bone. This necrosis occurs subsequent to vascular stasis resulting from

• Disruption of arterial blood supply to the underlying bone
• Disruption of venous drainage from the underlying bone
• Transection of the medullary arteries
• Concurrent microfacture of the adjacent cortex
• Formation of constricting bands of scar tissue

Answer 5

Disruption of arterial blood supply to the underlying bone​

Question 6

T/F: Sequestrum affects the periosteum, superficial cortex, and medullary cavity

Answer 6

False

Sequestrum affects the periosteum and superficial cortex. It does NOT affect the medullary cavity (this would be osteomyelitis)

Question 7

What degree of lameness would you expect to see in a patient with a sequestrum?

Answer 7

No lameness

Or only a very mild degree of lameness

Question 8

What is the treatment of choice for a sequestrum?

Answer 8

Surgery

Procedure: Sequestrectomy

Question 9

What is the most common cause of osteomyelitis in large animal patients?

Answer 9

Open fracture​