Osteomyelitis in the setting of hip prosthesis

(A) Coronal-reformatted computed tomography image demonstrates marked beam hardening artifact about a metallic left hip prosthesis (arrow).
(B) Despite extensive artifact in image A, on lung windows, a region of air can be identified adjacent to the lesser trochanter (arrow).
(C) Fluoroscopic-guided aspiration (arrow indicates needle) yielded 3 cc of pus. Initial Gram stain was positive for gram-negative rods; cultures subsequently grew Bacteroides fragilis.