Question: 50-year-old diabetic female s/p foot burn several weeks ago, now presenting with pain and discharge from a poorly healing wound. Diagnosis?
Answer: Osteomyelitis
Osteomyelitis
· Acute or chronic bone infection
· Risk factors: Immunosuppression (diabetes, chronic steroid use, AIDS, and sickle-cell dz.)
· Secondary to direct trauma, contiguous spread from local infection, or hematogenous spread (in children)
· Common bacteria: S. Aureus, Pseudomonas, Salmonellae (classically in Sickle cell dz.)
· X-ray (limited sensitivity):
- 3-5 days post-infection: Soft-tissue swelling
- 14-21 days: Some patients demonstrate bony changes (e.g., periosteal elevation, bone lucencies, etc.)
- >28 days: >90% with Xray findings
· MRI is the imaging gold standard
· Two of the following needed for diagnosis:
- Purulent aspiration
- Positive blood or tissue culture
- Positive imaging
- Tenderness + erythema / edema
· Antibiotic coverage based on culture results. When immediate empiric therapy required (sepsis), cover most likely pathogen plus MRSA.
References
Carek PJ, Dickerson LM, Sack JL. Diagnosis and management of osteomyelitis. Am Fam Physician. 2001 Jun 15;63(12):2413-20.
Pruthi S, Thapa MM. Infectious and inflammatory disorders. Radiol Clin North Am. Nov 2009;47(6):911-26.
Zink BJ, Raukar NP. Bone and Joint Infections. In: Marx JA, Hockberger RS, Walls RM, Adams JG, Barsan WG, Biros MH, Danzl DF, Gausche-Hill M, Ling LJ, Newton EJ, eds. 7th ed. Emergency Medicine: Concepts and Clinical Practice.Volume 2. Philadelphia, PA: Mosby; 2010:1821-1830.
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