The patient

A 58 year old man with long standing type 2 diabetes presented with a non-healing ulcer on the side of the right great toe, with associated spreading cellulitis. Laboratory tests showed a white blood cell count of 11.3×10⁹/l (normal range 3.2-9.8), a neutrophil count of 5×10⁹/l (3-5.8), and an erythrocyte sedimentation rate of 45 mm/h (normal <15). He had a history of peripheral neuropathy, peripheral vascular disease, and renal failure caused by diabetic nephropathy. He was referred for imaging of suspected osteomyelitis.

Osteomyelitis of the foot is a common and challenging problem in patients with diabetes.1 Around 25% of patients with diabetes will develop a foot ulcer, usually at areas of pressure, such as the heel or metatarsal heads.2 Osteomyelitis is almost always caused by contiguous spread of infection from overlying foot ulceration and complicates up to 20% of ulcers.3

The two major difficulties in diagnosing diabetic foot osteomyelitis are that imaging tests can be insensitive to early disease and that bony changes related to neuroarthropathy (Charcot’s foot) can mimic infective change. Accurate and early diagnosis of this condition is the key to successful management, which may include prolonged treatment with antibiotics or surgical resection.4 5

Clinicians should suspect osteomyelitis when a foot ulcer is deep, …