Paget's disease is a disease of increased but uncontrolled bone turnover. It is thought to be primarily a disorder of osteoclasts, with excessive osteoclastic resorption followed by increased osteoblastic activity. Paget's disease is common (UK prevalence 5%) but symptomatic in only 1 in 20 patients. The skull, spine/pelvis, and long bones of the lower extremities are most commonly affected.


  • Incidence: 10.00 cases per 100,000 person-years
  • Peak incidence: 70+ years
  • Sex ratio: more common in males 1.5:1
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+


Predisposing factors
  • increasing age
  • male sex
  • northern latitude
  • family history

Clinical features

Clinical features - only 5% of patients are symptomatic
  • the stereotypical presentation is an older male with bone pain and an isolated raised ALP
  • bone pain (e.g. pelvis, lumbar spine, femur)
  • classical, untreated features: bowing of tibia, bossing of skull


  • raised alkaline phosphatase (ALP) - calcium and phosphate are typically normal
  • other markers of bone turnover include: procollagen type I N-terminal propeptide (PINP), serum C-telopeptide (CTx), urinary N-telopeptide (NTx), and urinary hydroxyproline
  • skull x-ray: thickened vault, osteoporosis circumscripta


Indications for treatment include bone pain, skull or long bone deformity, fracture, periarticular Paget's
  • bisphosphonate (either oral risedronate or IV zoledronate)
  • calcitonin is less commonly used now


  • deafness (cranial nerve entrapment)
  • bone sarcoma (1% if affected for > 10 years)
  • fractures
  • skull thickening
  • high-output cardiac failure