A 49-year-old man presents with acute onset of a painful, swollen right knee for 2 days. He reports prior similar self-limited attacks involving the left wrist.

Examination of the right knee reveals swelling, warmth, a positive ballottement test, and restricted movement in all directions. 

Knee radiograph demonstrates chondrocalcinosis.

Right knee arthrocentesis was performed. Synovial fluid was examined under polarized light microscopy (as shown above). Gram stain and culture of the synovial fluid were negative.

Questions: 

1. Describe synovial fluid analysis findings 

2. What is the provisional diagnosis? 

3. What further investigations are indicated in patients under 55 years old with this condition? 

โดย น.อ.หญิง อินทิรา  อุไรเลิศ อายุรแพทย์โรคข้อและรูมาติสซั่ม กองอายุรกรรม รพ.ภูมิพลอดุลยเดช กรมแพทย์ทหารอากาศ

ANSWERs