musculoskeletal and connective tissue disorders
Osteomyelitis
Diagnosis of Osteomyelitis
Erythrocyte sedimentation rate or C-reactive protein X-rays, MRI, or radioisotopic bone scanning Culture of bone, abscess, or both (See also the2015 Infectious Diseases Society of America (IDSA) Clinical Practice Guidelines for the Diagnosis and Treatment of Native Vertebral Osteomyelitis in Adults.) is suspected in patients with localized peripheral bone pain, fever, and malaise or with localized refractory vertebral pain, particularly in patients with recent risk factors for Bacteremia . Chronic osteomyelitisis suspected in patients with persistent localized bone pain, particularly if they have risk factors. If osteomyelitis is suspected, complete blood count and erythrocyte sedimentation rate (ESR) or C-reactive protein, as well as plain x-rays of the affected bone, are obtained. Leukocytosis and elevations of the ESR and C-reactive protein support the diagnosis of osteomyelitis. However, the ESR and C-reactive protein may be elevated in inflammatory conditions, such as rheumatoid arthritis, or normal in infection caused by indolent pathogens. Thus, the results of these tests must be considered in the context of physical examination and imaging study results. X-rays become abnormal after 2 to 4 weeks, showing periosteal elevation, bone destruction, soft-tissue swelling, and, in the vertebrae, loss of vertebral body height or narrowing of the adjacent infected intervertebral disk space and destruction of the end plates above and below the disk. If x-rays are equivocal or symptoms are acute, CT and MRI are the current imaging techniques of choice to define abnormalities and reveal adjacent infections, such as paravertebral or epidural abscesses, or infected facet joints. Alternatively, a radioisotope bone scan with technetium-99m can be done. The bone scan shows abnormalities earlier than plain x-rays but does not distinguish between infection, fractures, and tumors. A white blood cell scan using indium-111–labeled cells may help to better identify areas of infection seen on bone scan. Bacteriologic diagnosis is necessary for optimal therapy of osteomyelitis; bone biopsy with a needle or surgical excision and aspiration or debridement of abscesses provides tissue for culture and antibiotic sensitivity testing. Culture of sinus drainage does not necessarily reveal the bone pathogen. Biopsy and culture should precede antibiotic therapy unless the patient is in shock or has neurologic dysfunction (eg, due to vertebral and spinal cord involvement). 