Osteomyelitis of a Finger: Emergency Department Evaluation and Management

Introduction to Osteomyelitis

The American College of Radiology recommends that suspected osteomyelitis of a finger warrants emergency department evaluation for prompt diagnosis and initiation of treatment, as delayed diagnosis can result in significant morbidity including bone necrosis, abscess formation, and potential loss of function or need for amputation 1, 2

The initial diagnostic workup in the ED should include obtaining plain radiographs of the affected finger as the first imaging test in all suspected cases, according to the American College of Radiology 3, 4, 5
The American College of Radiology also recommends ordering ESR and CRP as first-line inflammatory markers, with ESR >60 mm/hour or CRP >3.2 mg/dL combined with clinical findings helping to differentiate osteomyelitis from cellulitis 5
Obtaining two sets of aerobic and anaerobic blood cultures before starting antibiotics is crucial to identify hematogenous sources, as suggested by the American College of Radiology 5

Key clinical findings that increase the likelihood of osteomyelitis include visible or palpable bone through a wound, with a positive likelihood ratio of 9.2, according to the American College of Radiology 4
An erythematous and indurated "sausage" appearance of the finger and non-healing wound despite appropriate care are also indicative of osteomyelitis, as noted by the American College of Radiology 4
If radiographs are negative but clinical suspicion remains high, MRI with and without contrast is the preferred advanced imaging modality, with 97% sensitivity, 93% specificity, and 94% accuracy, according to the American College of Radiology 5, 6

The American College of Radiology suggests that antibiotic therapy should be started after obtaining cultures, targeting the likely causative pathogen, most commonly Staphylococcus aureus 1, 2
Admission for intravenous antibiotics is typically required initially, as recommended by the American College of Radiology 1, 2

Pediatric patients present unique challenges, with diagnosis being particularly challenging in children, as the typical triad of fever, pain, and diminished mobility is present in only slightly above 50% of cases, according to the American College of Radiology 1, 2
In children ≤18 months of age, infection can spread to the epiphysis due to transphyseal vessels, as noted by the American College of Radiology 1, 2