Osteomyelitis and Osteosarcoma

Question 1

Define osteomyelitis…

Answer 1

Infection of the cortical bone and medullary cavity (periosteum, cortex, endothelium and medullary cavity involved)

Question 2

Define osteitis…

Answer 2

Inflammation of the cortex without involvement of red or yellow bone marrow

Question 3

Describe the acute presentation of osteomyelitis and compare it to chronic presentation…

Answer 3

Acute - single limb lameness, rapid onset and short duration. History of laceration or surgery. Heat, pain, swelling on bony palpation, animal may be febrile.

Chronic - Moderate or intermittent lameness of days/weeks duration. Possible heat, pain, swelling on bony palpation, may be pus or fistula.

Question 4

How would you diagnose osteomyelitis?

Answer 4

Look for both bone lysis and formation (typical of infection and neoplasia)

Rads, C+S, biopsy

Question 5

How would you treat osteomyelitis?

Answer 5

Analgesia
Broad spec ABs (clindamycin, tetracycline)
Surgical debridement, immobilistation, lavage, rehabilitation

Question 6

What are the types of osteosarcoma?

Answer 6

Lytic
Proliferative
Destructive

Question 7

What is the usual presentation for an animal with osteosarcoma?

Answer 7

Unilateral limb lameness, non-responsive to analgesia or restriction in exercise, pain on deep bony palpation and bony swellings

Question 8

How can you diagnose osteosarcoma?

Answer 8

Clinical exam - LNs etc
Rads - Look for bony changes, met check on lungs
Bone biopsy - Take multiple samples through the centre of lesion

Question 9

How can we treat osteosarcoma?

Answer 9

Analgesia
Amputation only (4 months)
Amputation +/- chemo (12-14 months)
Lim sparing  +/- chemo (12-14 months)
Radiotherapy (palliative)
NSAIDs (palliative)
Euthanasia