A 74-year-old woman presents with recurrent acute knee arthritis. Radiographs show linear radiodense deposits in the articular cartilage. Synovial fluid analysis shows rhomboid, rod-shaped crystals that are weakly positively birefringent. Screening for which condition is most appropriate given her age and findings?
- A Haemochromatosis ✓
- B Ankylosing spondylitis
- C Ochronosis
- D Wilson disease
Correct answer: A. Haemochromatosis
Explanation
The crystals are calcium pyrophosphate dihydrate, giving chondrocalcinosis on radiograph. In a patient under about 55 years, CPPD deposition warrants screening for metabolic associations: hyperparathyroidism, haemochromatosis, hypomagnesaemia, and hypothyroidism. At 74 the yield is lower, but among the options offered haemochromatosis is the recognised screenable association tested in exams. Ochronosis and Wilson disease are not established causes of chondrocalcinosis, and ankylosing spondylitis is unrelated.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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