Review Question - QID 6716

A 58-year-old man with type 1 diabetes mellitus is seen in the emergency department and he reports a 3-day history of a red swollen foot but no history of trauma. Examination reveals that the skin is intact, and the patient has discomfort with passive range of motion at the ankle, hindfoot, and midfoot joints. He denies any fever. Laboratory studies show a WBC count of 7,800/mm³, an erythrocyte sedimentation rate of 40 mm/h, a C-reactive protein level of 23, and a serum glucose of 100. A radiograph and MRI scans are shown in Figures 16a through 16c. What is the next most appropriate step in management?