Paget's disease

Clinic

• Paget's disease = Paget's disease of bone= Osteitis deformans
• It is a condition involving cellular remodeling and deformity of one or more bones. The affected bones show signs of dysregulated bone remodeling at the microscopic level, specifically excessive bone breakdown and subsequent disorganized new bone formation.
• These structural changes cause the bone to weaken, which may result in deformity, pain, fracture or arthritis of associated joints.
• The exact cause is unknown, although leading theories indicate both genetic and acquired factors (see Causes).

Related diseases

• Osteoarthritis may be the result of mechanical changes in bone shape seen in Paget's disease.
• Heart failure is a rare, reported consequence of severe Paget's disease.
• Kidney stones are somewhat more common in patients with Paget's disease.
• Nervous system problems may occur in Paget's disease due to increased pressure on the brain, spinal cord, or nerves
• When Paget's disease affects the facial bones, the teeth may become loose. Disturbance in chewing may occur. Chronic dental problems may lead to infection of the jaw bone.
• Angioid streaks may develop, possibly as a result of calcification of collagen or other pathological deposition.

Paget vs Osteoporosis

• Note that Paget's disease is not associated with osteoporosis. A
• lthough Paget's disease and osteoporosis can occur in the same patient, they are different disorders.

Causes

• Viral: Paramyxoviruses including RSV and RBOL

• Genetic causes

Pathogenesis

The pathogenesis of Paget's disease is described in four stages:

1. Osteoclastic activity
2. Mixed osteoclastic – osteoblastic activity
3. Osteoblastic activity
4. Malignant degeneration