Makindo Medical Notes

Related Subjects: |Tennis Elbow |Golfer's Elbow |Painful Shoulder syndromes |Plantar fasciitis |Carpal tunnel syndrome |Chondrocalcinosis |Monoarticular arthritis |Polyarticular arthritis |Seronegative Spondyloarthropathies |Ankylosing spondylitis |Enteropathic Spondyloarthritis |Reactive Arthritis |Psoriatic Arthritis |Adult Onset Still's Disease |Alkaptonuria |Behcet's Syndrome

🦴 About

• Arthritis caused by calcium pyrophosphate deposition (CPPD) in cartilage and periarticular tissues.
• Predominantly affects those over 50 years (younger cases usually suggest an underlying metabolic disorder).
• Most common joint: knee (can also affect wrists, shoulders, hips, and ankles).
• Can mimic gout, rheumatoid arthritis, or osteoarthritis.
• Termed “pseudogout” when it presents with acute monoarthritis.

🧬 Aetiology

• Deposition of calcium pyrophosphate dihydrate crystals within articular cartilage → inflammatory response.
• Chondrocalcinosis on imaging reflects crystal deposition in cartilage.

🩺 Clinical Presentation

• Acute, red, hot, swollen joint – often the knee.
• May present with fever and raised inflammatory markers, mimicking septic arthritis.
• Can cause recurrent acute flares or chronic arthropathy resembling osteoarthritis (esp. in wrists/shoulders).

🔗 Key Associations (classic exam list)

CPPD is frequently linked to metabolic/systemic disease, often tested in MRCP & PACES:

• 🧪 Hyperparathyroidism
• 🩸 Haemochromatosis
• ⚡ Hypomagnesaemia
• 🦋 Hypothyroidism (myxoedematous)
• 🟤 Ochronosis (alkaptonuria)
• 🧬 Wilson's disease
• 💉 Dialysis-dependent renal failure
• 📏 Acromegaly

🔬 Investigations

• Synovial fluid analysis (polarized light microscopy):
  • Rhomboid-shaped crystals
  • Positively birefringent under polarized light
• 🔎 X-ray: Chondrocalcinosis (linear calcification in cartilage, especially knee meniscus and wrist TFCC).
• Blood tests: screen for metabolic associations (calcium, magnesium, iron studies, thyroid function, renal function).

💊 Management

• 🔹 Acute flare: joint aspiration + intra-articular corticosteroid injection; NSAIDs or colchicine if tolerated.
• 🔹 Supportive: rest, ice, analgesia.
• 🔹 Chronic/recurrent: low-dose colchicine prophylaxis; address underlying metabolic disorder.
• 🔹 Rehabilitation: physiotherapy to maintain joint function and mobility.

Cases — Chondrocalcinosis (Calcium Pyrophosphate Deposition Disease)

• Case 1 — Acute pseudogout flare 💥: A 71-year-old woman presents with acute, painful swelling of her right knee after a minor illness. Joint is hot, red, and tender. Aspirated synovial fluid: positively birefringent, rhomboid-shaped crystals. X-ray: calcification in menisci. Diagnosis: pseudogout attack due to chondrocalcinosis. Treated with NSAIDs and intra-articular steroid injection.
• Case 2 — Chronic arthropathy 🦴: A 66-year-old man with a history of haemochromatosis complains of progressive stiffness and pain in both wrists. Exam: reduced range of motion, no acute synovitis. X-ray: calcification in triangular fibrocartilage and joint space narrowing. Diagnosis: chronic CPPD arthropathy. Managed with analgesia and physiotherapy.
• Case 3 — Secondary cause 🔬: A 58-year-old woman with long-standing hypothyroidism develops recurrent swollen ankles and knees. Synovial fluid shows CPPD crystals. Investigations reveal associated hypomagnesaemia. Diagnosis: secondary chondrocalcinosis. Treated with magnesium replacement and joint-directed therapy.

Teaching Point 🩺: Chondrocalcinosis is due to calcium pyrophosphate deposition in cartilage. It can mimic gout, OA, or RA. Always check for secondary causes (haemochromatosis, hyperparathyroidism, hypomagnesaemia, hypothyroidism). Diagnosis: crystal analysis +