Osteomyelitis
Background
- Infection of the bone by bacteria or fungus
- Etiology
- Contiguous spread (80%)
- Hematogenous spread (20%)
- More common in pediatric (long bones)
- Less common in adults (spine)
Risk Factors
- Diabetic patients with one or more of the following:
- Skin ulceration >2cm
- Positive probe-to-bone test
- ESR >70 (83-92% Sn)
- Abnormal x-ray
Clinical Features
- Pain at the site
- May also have warmth, swelling, erythema
Differential Diagnosis
Skin and Soft Tissue Infection
- Cellulitis
- Erysipelas
- Lymphangitis
- Folliculitis
- Hidradenitis suppurativa
- Skin abscess
- Necrotizing soft tissue infections
- Mycobacterium marinum
Look-A-Likes
- Sporotrichosis
- Osteomyelitis
- Deep venous thrombosis
- Pyomyositis
- Purple glove syndrome
- Tuberculosis (tuberculous inflammation of the skin)
Evaluation
- X-ray
- May be normal early in the course
- Later will show bone demineralization, periosteal elevation, lytic lesions
- Changes 10-21 days after infection
- Sn 43-75%, Sp 75-83%[1]
- Blood culture
- CT
- Sn 67%, Sp 50%[2]
- MRI is the standard for diagnosis (as early as 3-5 days after infection)[3]
- Bone scan is sensitive, but lacks specificity vs. MRI
Management
Risk Factor | Likely Organism | Initial Empiric Antibiotic Therapy' |
Elderly, hematogenous spread | MRSA, MSSA, gram neg | Vancomycin 1gm + (Piperacillin/Tazobactam 3.375 grams OR imipenem 500mg) |
Sickle Cell Disease | Salmonella, gram-negative bacteria | Ceftriaxone 50mg/kg IV once daily OR Cefotaxime 50mg/kg IV three times daily, PLUS
|
DM or vascular insufficiency | Polymicrobial: Staph, strep, coliforms, anaerobes | Vancomycin 1gm + (Piperacillin/Tazobactam 3.375 grams OR imipenem 500mg) |
IV drug user | MRSA, MSSA, pseudomonas | Vancomycin 1gm |
Newborn | MRSA, MSSA, GBS, Gram Negative | Vancomycin 15mg/kg load, then reduce dose, AND ceftazidime 30mg/kg IV q12 h |
Children | MRSA, MSSA | Vancomycin 10mg/kg q6 h AND ceftazidime 50mg/kg q8hr |
Postoperative (ortho) | MRSA, MSSA | Vancomycin 1gm |
Human bite | Strep, anaerobes, HACEK organism | Piperacillin/Tazobactam 3.375gm OR imipenem 500mg |
Animal bites | Pasteurella, Eikenella, HACEK organism | Piperacillin/Tazobactam 3.375gm OR imipenem 500mg |
Foot puncture wound | Pseudomonas | Anti-pseudomonal, staph coverage |
See Also
References
- ↑ Pineda et al. Semin Plast Surg 2009;23:80–89.
- ↑ Pineda et al. Infect Dis Clin N Am. 2006, 20: 789–825
- ↑ Pineda C et al. Radiographic Imaging in Osteomyelitis: The Role of Plain Radiography, Computed Tomography, Ultrasonography, Magnetic Resonance Imaging, and Scintigraphy. Semin Plast Surg. 2009 May; 23(2): 80–89.