hydroxyapatite deposition disease; calcium hydroxyapatite deposition disease; basic calcium phosphate deposition disease

Etiology

• often occurs in the setting of trauma

Epidemiology

• mostly occurs in women

Pathology

• deposition of calcium hydroxyapatite in synovial joints & tendon sheaths

Clinical manifestations

• acute inflammation
  • calcific tendonitis
  • osteoarthritis
  • periarthritis/arthritis dialysis syndrome
  • rupture of calcinotic deposits in scleroderma
• chronic inflammation
  • glenohumeral osteoarthritis
  • rotator cuff tear
  • Milwaukee shoulder
• active motion is limited
• passive motion may be preserved
• may be asymptomatic

Laboratory

• synovial fluid
  • individual crystals cannot be seen on routine polarization microscopy
  • small, round bodies 0.5-100 um seen as lumps of crystals
  • positive identification requires electron microscopy or elemental analysis
  • Alizarin red staining for Ca+2 plus exclusion of CPPD provides presumptive diagnosis
  • non-inflammatory: case with 8300 leukocytes/uL

Radiology

• X-ray may show articular & periarticular dystrophic calcification

Differential diagnosis

• pseudogout with inflammatory synovial fluid

Management

• NSAIDs
• intra-articular glucocorticoids
• colchicine
• joint aspiration & tidal lavage

More general terms

• crystalline arthritis (crytalline arthropathy)
• chronic inflammation

More specific terms

• Milwaukee shoulder/knee syndrome

Additional terms

• hydroxyapatite