Patient Case: Basic Calcium Phosphate (BCP) Deposition Disease
A 55-year-old female presents to the orthopedic clinic with progressive shoulder pain and stiffness over the past six months. She describes the pain as deep, aching, and worse with movement, particularly when lifting her arm above her head. She denies any history of trauma but reports mild swelling and warmth around the shoulder. Over-the-counter pain medications have provided only minimal relief.
Medical History & Social Background
• Medical history: Hypertension, osteoarthritis in the knees, and type 2 diabetes mellitus.
• No prior history of gout, rheumatoid arthritis, or systemic connective tissue diseases.
• Occupation: Office worker with limited physical activity.
• Social history: No alcohol use, non-smoker.
Physical Examination
• Localized tenderness and swelling around the right shoulder.
• Restricted range of motion, especially with abduction and external rotation.
• No significant joint erythema, but mild warmth is noted.
• Negative provocative tests for rotator cuff tears.
• No signs of systemic inflammation (no fever, normal vital signs).
Laboratory & Imaging Findings
• Serum inflammatory markers (CRP, ESR): Normal.
• Serum calcium and phosphate levels: Normal.
• Serum uric acid: Normal.
• Synovial fluid analysis: No urate or pyrophosphate crystals, no infection.
• Shoulder X-ray: Periarticular calcifications in the rotator cuff tendons.
• Ultrasound: Confirms calcific deposits within the supraspinatus tendon, consistent with basic calcium phosphate (BCP) crystal deposition disease.
Diagnosis
The patient is diagnosed with basic calcium phosphate (BCP) deposition disease, specifically calcific tendinitis of the shoulder, which occurs due to hydroxyapatite crystal accumulation in periarticular structures.
Management Plan
1. Pain & Inflammation Control
• NSAIDs (e.g., ibuprofen, naproxen) for pain relief.
• Physical therapy to improve range of motion and prevent stiffness.
• Ultrasound-guided corticosteroid injection if symptoms persist.
2. Advanced Interventions for Refractory Cases
• Needle aspiration and lavage (barbotage) for persistent cases.
• Shockwave therapy to break down calcium deposits.
• Surgical removal in cases with severe functional impairment.
3. Monitoring & Prevention
• Regular follow-up with imaging to assess resolution or progression.
• Screening for metabolic disorders (though most cases occur in idiopathic settings).
• Lifestyle modifications, including shoulder-strengthening exercises.
Challenges & Considerations
Diagnosis is often delayed due to overlap with other shoulder pathologies (e.g., rotator cuff tears, osteoarthritis).
BCP crystals do not show up under polarized light microscopy, making them harder to identify than urate or pyrophosphate crystals.
Calcific deposits may resolve spontaneously but can cause prolonged symptoms in some patients.
Prognosis
Most cases resolve with conservative management, but some patients may experience chronic shoulder dysfunction, requiring more aggressive treatment. Early intervention with physical therapy and anti-inflammatory medications is crucial for optimal outcomes.
A) Gout
B) Rheumatoid arthritis
C) Basic calcium phosphate (BCP) deposition disease
D) Calcium pyrophosphate deposition disease (CPPD)
A) Punched-out erosions with overhanging edges
B) Chondrocalcinosis in joint cartilage
C) Periarticular calcifications in tendons
D) Joint space narrowing with osteophyte formation
A) BCP crystals are too small to be seen under conventional light microscopy
B) Synovial fluid is always normal in BCP deposition disease
C) BCP crystals appear as rhomboid-shaped, positively birefringent structures
D) Synovial fluid analysis is unnecessary for diagnosing BCP deposition disease
A) Methotrexate and hydroxychloroquine
B) Nonsteroidal anti-inflammatory drugs (NSAIDs) and physical therapy
C) Allopurinol and colchicine
D) Long-term corticosteroids and immunosuppressants
