Osteomyelitis

Question 1

Define Osteomyelitis

Answer 1

Inflammatory condition of the bone caused by an infective organism
usually a single bone (peripheral or axial)

either heamatogenous or contiguous focus

acute (more common in children) or chronic (more common in adults)-acute can evolve to chronic

Question 2

Aetiology and risk factors of Osteomyelitis

Answer 2

Most common causative organism-staph aureus, enterobacteriae (e.coli, kleb)
can result from heamatogenous infection -from blood. Or contiguous focus-local spread of infection

IV drug use is a risk of heamatogenous infection
Nowadays, contiguous focus osteomyelitis happens mainly after surgery/trauma, -implants esp

risk factors:
PMHx of osteomyelitis (chronic)
penetrating injury
Surgery/implant
IV drug use
Diabetes/HIV

Question 3

Epidiemology of Osteomyelitis

Answer 3

about 2% per year in developed countries
-surgery and trauma being big causes

about 2.1 cases per 100 000

Question 4

Signs and Sx of Osteomyelitis

Answer 4

can present as emergency in acute osteomyelitis, or as a flare up of chronic osteomyelitis

adult-nearly always flare up of chronic (which can be 1st presentation)–fever, bone pain, reduced mobility
and local erythema, oedema, hotness
always consider spesis

children tend to come with limp+ fevers

Chronic -
hallmark-constant drainage from a wound near the site
Non specific bone pain-one bone
constant Low grade fever, fatigue, malaise

always make sure to examine range of movement-tends to be lowered
and where the infection could be from–diabetic foot/diabetic ulcers are common causes
diabetic patient might not even have the pain-just hard to control hyperglycemia

Question 5

Investigations of Osteomyelitis

Answer 5

FBC-raised WCC
CRP/ESR-raised
microbiology samples–Before starting ABX-gold standard

plane X-ray of affected area–
in acute-can be initially normal
zone of osteopenia after 6-7 days
Round hypoteense lesion in the middle of bone