Osteomyelitis
- Diagnosis
- Monitoring
- Background
- Lab Tests
- References
- Related Topics
Indications for Testing
- History and physical examination suggestive of osteomyelitis
- Chronic, nonhealing ulcer that can be probed to the bone (particularly in a diabetic patient)
Laboratory Testing
- CBC – may help in differentiating bacterial etiology versus other cause
- Frequently shows leukocytosis and left shift to immature forms
- May be normal in chronic osteomyelitis
- C-reactive protein (CRP)
- Preferred test to detect inflammatory processes (Choosing Wisely: 5 Things Physicians and Patients Should Question, 2015; American Society for Clinical Pathology)
- Frequently elevated, but not diagnostic
- If CRP not available, order erythrocyte sedimentation rate (ESR)
- Procalcitonin may be helpful in children – not often used and does not outperform CRP
- Blood culture – in all suspected cases
- Requires 3-5 sets from separate venipuncture sites
- Positive in ≤50% of children
- Bone culture – necessary for most patients
- PCR – not widely available; may be useful if all cultures are negative
- Most useful for Bartonella henselae and Kingella kingae
Imaging Studies
- Plain x-ray films – may not demonstrate presence of osteomyelitis until 10-14 days after infection is established
- Negative film does not rule out diagnosis
- Evidence for osteomyelitis on film – periosteal lifting or lytic lesions
- Bone scan with technetium-99 pyrophosphate – most useful if 3-phase scintigraphy is used
- 90% sensitive in long bone osteomyelitis
- MRI – probably most sensitive imaging tool but may not distinguish infections from other bone disorders
- Evidence for osteomyelitis – bone marrow edema, abscesses
- May need to use 18FDG-PET for vertebral osteomyelitis
- CT – not as sensitive as MRI; not useful if metal is near the infection
- In acute osteomyelitis, CT can depict changes earlier in disease process than plain imaging
Differential Diagnosis
- Arthritis
- Septic
- Degenerative
- Crystalline
- Reactive
- Juvenile rheumatoid arthritis
- Neuropathic disease
- Metastatic bone disease
- Paget disease
- CRP – may be helpful in gauging success of therapy
- Declining values suggest favorable treatment response
Osteomyelitis is an infection of the bone acquired hematogenously or by contiguous site infection.
Epidemiology
- Incidence – 2/10,000
- Sex – M>F (slight risk increases through childhood, peaks in adolescence, and falls to a low ratio in adults)
- Age – bimodal age distribution
- Children – acute hematogenous osteomyelitis
- Adults – direct trauma/contiguous focus osteomyelitis; vertebral osteomyelitis
Risk Factors
- Children
- Blunt trauma
- Postoperative
- Adults
- Peripheral vascular disease
- Diabetes mellitus
- Renal or hepatic failure
- Immunosuppression
- Malignancy
- Neuropathy
- Intravenous drug use
- Trauma
- Surgery – particularly prosthetic implants
Organisms
- Most common organism – Staphylococcus aureus
- Diabetes mellitus, peripheral vascular disease – Streptococcus spp, coagulase-positive and -negative Staphylococcus spp, Enterococcus spp, anaerobic spp, often polymicrobial
- Intravenous drug use – Pseudomonas aeruginosa
- Infants and children – Staphylococcus spp, S. pneumoniae, Group A Streptococcus (especially post-chickenpox), Kingella kingae
- Neonates – Group B Streptococcus, gram-negative species
- Hemoglobinopathies – Salmonella spp
Clinical Presentation
- Constitutional – fever, nonspecific pain
- Soft tissue inflammation overlying area of osteomyelitis
- Open and nonhealing wound over area of bone
- Vertebral disease – may present with severe back pain
- Children
- Limping, reluctance to walk
- Fever
- Focal tenderness
- Swelling
CBC with Platelet Count and Automated Differential 0040003
Method: Automated Cell Count/Differential
Initial test for differentiating bacterial from viral infection
Blood Culture 0060102
Method: Continuous Monitoring Blood Culture/Identification
Detect presence of bacteria in blood
Limited to the University of Utah Health Sciences Center only
C-Reactive Protein 0050180
Method: Quantitative Immunoturbidimetry
Preferred test to detect inflammatory processes
Bone Culture and Gram Stain 0060103
Method: Culture/Identification
Identify bacteria in bone specimens
Guidelines
American Society for Clinical Pathology. Choosing Wisely - Five Things Physicians and Patients Should Question. An initiative of the ABIM Foundation. [Last revision Feb 2015; Accessed: Jan 2016]
General References
Calhoun JH, Manring MM. Adult osteomyelitis. Infect Dis Clin North Am. 2005; 19(4): 765-86. PubMed
Hatzenbuehler J, Pulling TJ. Diagnosis and management of osteomyelitis. Am Fam Physician. 2011; 84(9): 1027-33. PubMed
Palestro CJ, Love C, Miller TT. Infection and musculoskeletal conditions: Imaging of musculoskeletal infections. Best Pract Res Clin Rheumatol. 2006; 20(6): 1197-218. PubMed
Peltola H, Pääkkönen M. Acute osteomyelitis in children. N Engl J Med. 2014; 370(4): 352-60. PubMed
Medical Reviewers
Last Update: September 2016
