Obtain deep wound culture after cleaning and debriding wound. Superficial culture results correlate poorly with true pathogen
If probing the ulcer base goes directly to bone, this is highly suggestive of osteomyelitis. Obtain a plain X-ray. Further imaging is usually unnecessary except when required for surgical planning
Assessment for peripheral arterial disease should be done for every diabetic with a foot ulcer. If dorsalis pedis or posterior tibialis pulses are not easily palpated, ankle-brachial index (ABI) and toe pressures should be done (if not done in past 12 months):
Plain X-ray of the involved area should be done as baseline
MRI is the most sensitive and specific imaging modality to diagnose soft-tissue complications or osteomyelitis
Bone scan is helpful to rule out osteomyelitis if negative, but a positive result is not specific. False negatives may be seen in severe peripheral arterial disease. It can be combined with SPECT/CT to provide better three-dimensional localization
White blood cell-labelled radionuclide scan has good performance to detect osteomyelitis. It can be combined with SPECT/CT to provide better three-dimensional localization