Osteomyelitis Diagnosis and Treatment

Initial Evaluation

The American College of Physicians recommends obtaining inflammatory markers (ESR, CRP, or procalcitonin) when clinical examination is equivocal or to support the diagnosis, but recognizes these are non-specific and cannot rule out osteomyelitis when normal 1, 2
ESR and CRP are the most useful inflammatory markers for initial evaluation, according to the Infectious Diseases Society of America 3, 1, 2
Procalcitonin (PCT) may be helpful when clinical findings are diagnostically uncertain, as suggested by the American College of Physicians 1, 2

The Infectious Diseases Society of America recommends obtaining bone samples for culture (not soft tissue) either intraoperatively or percutaneously to identify causative organisms and guide antibiotic therapy 3, 1, 2
Intraoperative excisional biopsy during debridement is preferred over core needle biopsy because osteomyelitis can be focal, according to the Infectious Diseases Society of America 4, 5
Bone cultures have 76-100% sensitivity but only 8-67% specificity; combining with histopathology is recommended for definitive diagnosis, as suggested by the Infectious Diseases Society of America 4, 5

The American College of Radiology recommends starting with plain radiographs, then proceeding to MRI if diagnosis remains uncertain—MRI is the gold standard with 97% sensitivity and 93% specificity 3, 2, 7
Plain radiographs should be used first in all suspected cases, according to the American College of Radiology 3, 1, 2, 7
MRI with and without contrast should be used when diagnosis remains uncertain, as recommended by the American College of Radiology 3, 1, 2, 7

The Infectious Diseases Society of America recommends administering antibiotics for 1-2 weeks for soft tissue infections; 4-6 weeks for osteomyelitis without surgical resection; and considering up to 3-4 weeks for extensive soft tissue infections with severe PAD 3, 1, 6
Soft tissue infection only should be treated with 1-2 weeks of antibiotics, according to the Infectious Diseases Society of America 1
Osteomyelitis without surgical resection should be treated with ≥4-6 weeks of antibiotics, as recommended by the Infectious Diseases Society of America 3, 6

The American College of Surgeons recommends surgical debridement for chronic osteomyelitis with necrotic bone, and considering surgery for persistent sepsis syndrome despite appropriate antibiotics, severe infection with exposed bone, progressive bone destruction despite appropriate therapy, mid or hindfoot lesions, and peripheral arterial disease requiring revascularization 6
The American College of Surgeons also recommends not delaying referral to a multidisciplinary team (infectious disease, orthopedic/podiatry, vascular surgery) for diabetic foot osteomyelitis, and not failing to assess vascular status—adequate blood supply is essential for healing and antibiotic delivery 6