Review Question - QID 215157

A 63-year-old diabetic female presents with progressively worsening right knee pain over the last 10 months. She underwent a right total knee arthroplasty 3 years ago and her immediate post-op course was uncomplicated. She denies any fevers, chills, or wound drainage. Examination reveals a well-epithelialized incision without surrounding erythema, drainage, or fluctuance. Pain is elicited with range of motion. Her current radiographs are shown in figures A and B. Recent laboratory studies include WBC count of 7.2k cells/mm^3 (reference 4.5k - 11k cells/mm^3), ESR 41 mm/hr (reference 0-20 mm/hr), and C-reactive protein 6.3 mg/L (reference <3.0 mg/L). What is the most appropriate next step in treatment?