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Osteomyelitis
Aka: Osteomyelitis
- Classification: Waldvogel System
- Acute Osteomyelitis: Hematogenous Seeding
- Child with long bone metaphysis infection
- Chronic Osteomyelitis: Wound associated
- Adult with open injury to bone and soft tissue
- Contiguous spread of infection
- No generalized vascular disease
- Generalized vascular disease
- Causes
- See Osteomyelitis Causes
- Types
- Acute Osteomyelitis
- Typical case is a 1-2 week history of fever, Joint Pain in the long bone of a child (hematogenous spread)
- Chronic Osteomyelitis
- Typical case is a 4-6 week history of malaise, regional pain at an open wound in an adult (contiguous spread)
- Labs
- Inflammation markers
- General
- More useful in children, especially in ruling out Osteomyelitis (serial negative markers)
- Sensitive, but not specific
- Complete Blood Count (CBC)
- Leukocytosis
- Erythrocyte Sedimentation Rate (ESR) exceeds 70
- Test Sensitivity: 28%
- C-Reactive Protein (CRP)
- Bone Biopsy (Gold Standard)
- Test Sensitivity: 95%
- Specificity: 99%
- Polymicrobial infections are more common in Chronic Osteomyelitis
- Consider specific testing in atypical cases (e.g. Mycobacterium tuberculosis)
- Blood Culture
- Test Sensitivity: <50%
- Positive Blood Culture with clinical findings suggestive of Osteomyelitis may obviate the need for bone culture
- Superficial wound culture
- Not recommended due to contamination
- Imaging
- Osteomyelitis XRay
- Typical appearance is the "rat bite" of destroyed bony cortex
- First line study due to low cost and high availability
- Narrows differential diagnosis by ruling out other causes
- Typically normal in first 2-3 weeks (esp. acute Osteomyelitis in Children)
- Osteomyelitis Bone Scan
- Low Test Specificity (can not distinguish Osteomyelitis from Trauma or recent post-surgical changes)
- Distinguishes Cellulitis from Osteomyelitis
- In combination with Leokocyte Scintigraphy, efficacy approaches that of MRI
- Consider in patients for whom MRI is contraindicated (e.g. due to Pacemaker)
- Osteomyelitis MRI
- Best Test Sensitivity and Specificity (except in region of surgical hardware)
- Best distinguishes soft tissue infection from bone infection and defines infection margins
- Osteomyelitis PET
- Very high Test Sensitivity and Test Specificity, but cost prohibitive
- Osteomyelitis CT
- Avoid for Osteomyelitis evaluation unless MRI contraindicated
- May also identify soft tissue abscess, gas formation, foreign bodies and bony destruction
- Bone Ultrasound Findings (may have niche applicability, such as in Sickle Cell Disease related Osteomyelitis)
- Bone abscess
- Periostitis
- Management
- See Osteomyelitis Management
- See Suspected Osteomyelitis in Diabetes Mellitus
- References
- Jhun and Raam in Herbert (2016) EM:Rap 16(2):15-6
- Boutin (1998) Orthop Clin North Am 29:41-66 [PubMed]
- Carek (2001) Am Fam Physician 63(12):2413-20 [PubMed]
- Dirschl (1993) Drugs 45:29-43 [PubMed]
- Eckman (1995) JAMA 273:712-20 [PubMed]
- Haas (1996) Am J Med 101:550-61 [PubMed]
- Lew (1997) N Engl J Med 336:999-1007 [PubMed]
- Lipsky (1997) Clin Infect Dis 25:1318-26 [PubMed]