Osteomyelitis Flashcards
What is osteoyelitis
An infection of bone and is inflammatory
How is osteomyelitis characterised
characterised by high fever, sweating, chills, pain, nausea, pus formation, oedema and warmth over affected bone and ridged overlying muscles
How is osteomyelitis caused
Often caused by bacteria
bacteria may reach the bone from outside the body or from other sites of infection inside the body
What is endogenous cause of osteomyelitis
Inside Body–>Pathogen is within the body
Hematogenous– usually spreads via blood
Cutaneous Lesion
Common sites of bacteria: ear, dental, GI tract, UTI
What is exogenous cause of osteomyelitis
From outside body via : open #'s/ penetrating wounds punch to teeth surgical interventions diabetic foot ulcers (poor blood supply and increased sugar levels=increased water, hence decreased blood cell concentration, hence more pressure inside blood vessels= atherosclerosis IV drug users pyogenic Tuberculosis and Syphilis (congenital and acquired)--> both more common in poorer countries
What is pyogenic
Type of osteomyelitis formed by pus forming microorganisms–> hence bacteria
90% is from Staphyloccous aureus: MRSA
Also acquired from an exisiting infection, trauma/surgery, drug users, diabetics (legs, feet and toes)
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Where/when is pyogenic osteomyelitis most susceptible
Exposure to open wound and virulence
Underlying diseases/health
Type and location of bone–> usually LL, vertebrae, long bones, pelvis, clavicle
Vascularity of bone area–> how well supplied hence inflammatory cell access; also the blood supply to and drainage from the area of infection (lymph)
How will pyogenic osteomyelitis present
Slow and insidious
Acute, febril, fever and chills, fatigue, lethargy (bacteria=toxins produced= drop/increase in temp)
Leucocytosis = increase in WBC = acute inflammation
Throbbing local pain (from pressure)–> red, swollen and tender under skin lesions
What is the effect of pyogenic osteomyelitis in young adults
young adults still have epiphyseal plate
Epiphyseal plate is vascular and therefore infection spreads to joint surface which results in septic arthritis (bacteria in joint)
How are sinus tracts formed
Pressure will find a way to release and will do so by going through the weakest point
The path that the pressure takes is the sinus tract
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What is an involucrum
A layer of new bone growth outside a sequestrum (area of dead bone), in an attempt to repair, but getting more damaged
What is the effect of osteomyelitis on children
Swelling causes lifting of periosteum (this is a big blood supplier and therefore compromises blood supply to the area = necrosis = sequestrum)
Lifted periosteum activates osteoblasts which lay down new bone which surrounds infected bone (involucrum)
This is surrounded by bacterial growth therefore pressure and hence causes sinus tracts
Increased pressure forces exudate into medullary cavity
What is the effect of osteomyelitis on adults
Periosteum is well fixed to bone hence not lifted off
If # healing then that is a weak spot
Pressure and infection destroys/weakens the cortex and therefore is pathlogical
What are some complication of osteomyelitis
Septicemia–> when bacteria infects blood stream (affects heart valces, affecting mainly infants)
Acute bacterial/septic arthritis
Pathological #–> heal poorly and may require surgical drainage
SCC–> in bone or sinus tract from years of chronic inflammation
Chronic osteomyelitis
Amyloidosis (from years of chronic)
What type of disease is tuberculosis
Exogenous octeomyelitis
