Laboratory findings in osteomyelitis include increased acute phase reactants (ESR and CRP) levels and leukocytosis.^[1] Blood cultures should be performed in all suspected cases. Bone probing and direct sampling is a reliable method, especially in diabetic ulcers which are contaminated with many flora.

Microbiology and histopathology are essential for diagnosis and determining treatment of osteomyelitis.

• Histopathology of bone biopsy samples typically provides the most accurate diagnosis.
• Blood cultures are typically more reliable for hematogenous or vertebral osteomyelitis.
• Samples obtained from swabbing sinus tracts should not be used as the isolate may be contaminated with non-pathogenic microorganisms.

Isolation techniques to determine the causative agent include:

• Blood cultures
• Bone biopsy (which is then cultured)

Laboratory tests to determine infection include:^[2][3]

• Complete blood count (CBC)
• C-reactive protein (CRP)
• Erythrocyte sedimentation rate (ESR)
• Note: white blood cell count (WBC) is typically normal and therefore not reliable