Calcium pyrophosphate deposition disease (pseudogout) most commonly affects which joint, and the characteristic radiological finding is:
- A First MTP joint; periarticular soft tissue calcification
- B Knee joint; chondrocalcinosis (calcification within fibrocartilage of menisci and hyaline cartilage) ✓
- C Hip joint; joint space narrowing with sclerosis
- D Shoulder joint; supraspinatus tendon calcification
Correct answer: B. Knee joint; chondrocalcinosis (calcification within fibrocartilage of menisci and hyaline cartilage)
Explanation
CPPD (calcium pyrophosphate deposition disease / pseudogout) most commonly affects the knee joint and is characterized radiologically by chondrocalcinosis — linear calcifications within the fibrocartilage (menisci) and articular hyaline cartilage. This is distinct from gout (affecting first MTP with soft tissue tophi) and hydroxyapatite deposition (calcific tendinitis of rotator cuff). Aspiration of CPPD crystals reveals rhomboid-shaped, weakly positive birefringent crystals under polarized light.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.