Osteomyelitis question

[grigory76]

There is a contradiction between surgical and IM Kaplan video lectures as far as the diagnostic algorithm goes for acute osteomyelitis. Surgery states that you go straight for Technetium scan while IM (Dr. Conrad Fischer) states that you do x-ray and then MRI if x-ray is uninformative/equivocal, and that Tc scan is not really used much.
USMLE World also states that Tc scan is the most appropriate dx test for acute ost. and you go straight for it.
Also- Dr. Fischer stated that before giving abx you do bone bx first and then start treatment, while USMLE World states you do blood cultures, then start treatment, and if blood cultures come neg you do bone bx. I thought you don’t do bone bx after you have started treatment.
What’s the truth on Step 2?
Thanks

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[Megalofyia]

I would go with doing an x-ray and then a bone biopsy to confirm your findings. The x-ray may show osteolysis, periosteal reaction and sequestra. A blood culture may show up as negative with osteomyelitis so I would becareful with doing a blood culture.

 

[cubsfan]

From what I understand and from what I was taught on my peds and IM rotations:
1) Do not do an X-Ray b/c nothing is likely to show up for some time
2) If you suspect--begin empiric tx and send for cultures
3) The bone scan is nice...but in regards to "board" world vs. "real" world--its my understanding tx empirically for the infection while waiting for the cultures to come back. If you are wrong--bye bye bone

 

[grigory76]

Cubsfan,
what culture do you mean- bone or blood? I understand that you HAVE to biopsy bone and send it for cultures as it will give the most precise C&S compared to blood C&S. And you sure start abx empirically while waiting for C&S.
The question on what dx study goes 1st remains open...

 

[cubsfan]

Cubsfan,
what culture do you mean- bone or blood? I understand that you HAVE to biopsy bone and send it for cultures as it will give the most precise C&S compared to blood C&S. And you sure start abx empirically while waiting for C&S.
The question on what dx study goes 1st remains open...

Do not wait. The timetable should be to get an aspirate b/c only 50-60% of cultures are actually positive and X-rays are initially normal. It can take up to 2-3 weeks for abnormalities to appear on a XRay.

TX: IV Abx for 4-6wks. Can treat empirically with antistaph agents (oxacillin, for example) unless the patient is a neonate (need GBS coverage).

Comon bugs to remember: S.A. #1 and Sickel Cell = Salmonella for the boards.

Is this clearer?

 

[adeelmd]

This is summarized from cmdt 2004

Basically, if the cause of osteomyelitis is hemategenous then you do blood cultures (will be positive) (ie children, sickle cell)

but if the cause osteomyelits is contiguous spread from an ulcer or infection (dibetes, older person) you must do a bone biopsy. Culture of ulcer or infection is not reliable.

For "board" reasons, X-ray is the first step... MRI is the MOST sensitive... Bone scan when you can't locate the lesion.

Another point, in sickle cell anema, the organism is Salmonella (Paratyphi) (cmdt agrees with UW, and cmdt pretty much trumps any other source).. Just wanted to add that it is paratyphi and not typhoid (though I don't remember where I remember this from)

 

[Idiopathic]

Salmonella paratyphi in Sickle patients


Thats how I remember it

 

[grigory76]

Thank you folks

 

[1 D.O.]

There is a contradiction between surgical and IM Kaplan video lectures as far as the diagnostic algorithm goes for acute osteomyelitis. Surgery states that you go straight for Technetium scan while IM (Dr. Conrad Fischer) states that you do x-ray and then MRI if x-ray is uninformative/equivocal, and that Tc scan is not really used much.
USMLE World also states that Tc scan is the most appropriate dx test for acute ost. and you go straight for it.

Strong Medicine says:
three phase bone scan is initial test and mri is most diagnostic!