3.9 of 8 Ratings
A 67-year-old man who underwent knee arthroplasty 7 years ago now reports the recent onset of pain and swelling. He denies any recent illness or change in medical status. Examination of the knee reveals a moderate effusion, slight warmth when compared to the contralateral knee, and no tenderness. Pain is increased with weight bearing. Laboratory studies show a WBC count of 6,300/mm3 (normal 3,500-10,500/mm3), a hemoglobin level of 10.1 g/dL, an erythrocyte sedimentation rate of 25 mm/h (normal up to 20 mm/h), C-reactive protein (CRP) level of 0.3 mg/dL (normal less than 0.5 mg/dL), and a uric acid level of 6.2 mg/dL (normal 2.5-7.0 mg/dL). Postoperative and current radiographs are shown in Figures 8a and 8b. What is the most likely diagnosis?
Dislodgement of polyethylene
Select Answer to see Preferred Response