Review Question - QID 8087

Figures 65a through 65c are the weight-bearing radiographs of a 42-year-old male manual laborer who has a 6-month history of persistent great toe swelling and pain after undergoing a total joint arthroplasty for hallux rigidus 9 months ago. He denies postoperative wound complications, recent fevers, chills, or other constitutional signs; however, he has never been able to ambulate without pain since his return to work. Examination reveals moderate diffuse swelling, but no fluctuance or drainage. Range of motion includes 25° of dorsiflexion. Laboratory studies show an erythrocyte sedimentation rate of 18 mm/h and a c-reactive protein level of <0.7 mg/L. What is the most likely source of his symptoms?