Paget's disease

Paget's disease

• a chronic disorder of the adult skeleton in which new soft bone replaces localised areas of normal bone
• cause unknown 

Clinical features

• M:F ratio 2:1
• 95% asymptomatic 
• symptoms include joint pain and stiffness (e.g. hips, knees), bone pain (usually spine), deformity. headache and deafness
• Bone pain is typically deep and aching; it occurs at rest, particularly at night
• signs may include deformity, enlarged skull, bowing of tibia, waddling gait and hyper dynamic circulation 

Diagnosis

• Page's disease is diagnosed radiologically 
• early: lytic lesions or flame shaped, advancing lytic wedges in long bones
• late: mixed lytic and sclerotic areas, thickened trabecular, bone expansion, cortical thickening and deformity
• isotope bone scanning is more sensitive

Investigation (2)

• Plasma alkaline phosphatase
• Liver function tests
• Vitamin D levels
• Isotope bone scan
• Radiography of affected bones

Treatment 

• Asymptomatic disease dose not require treatment
• indications for treatment 
• pain 
• neurological complications 
• significant osteolytic lesions 
• involvement of long bones, vertebrae or base of skull 
• before surgery involving pagetic bones
• significant joint involvement 
• Recommended drugs
• zoledronic acid 5 mg single dose, given IV over 15 mins
• alendronate 40 mg daily, given orally for 3-6 months
• risedronate 30 mg daily, given orally for 2 months

References

1. John Murtagh p.747
2. http://www.racgp.org.au/afp/2012/march/paget-disease-of-bone/