PAGET’S DISEASE

Paget’s disease of bone is characterized by one or more bony lesions having high bone turnover and disorganized osteoid formation.

Involved bone becomes vascular, weak, and deformed.

• It is the disease of the elderly seldom seen before age 40, mostly identified incidentally on radiography or raised alkaline phosphatase

• The pelvis, femur, tibia, lumbar spine, skull, and scapula are principally affected.

Pathogenesis

• The primary abnormality is increased osteoclastic bone resorption which is accompanied by marrow fibrosis,

increased vascularity of bone and decreased osteoblastic activity.

• Genetic factors are clearly important and family history is present in about 15% of
cases.

Clinical features

• The classic presentation is bone pain, deafness, and pathologic fractures.

• The bones become soft, leading to bowed tibias, kyphosis, and frequent fractures with
slight trauma.

• If the skull is involved, the patient may report headache, increased hat size, and deafness because affected bones enlarge and encroach the nerve foramina.

• Increased vascularity over-involved bone causes increased warmth and can precipitate high cardiac output failure.

• Osteosarcoma is a rare complication.

Investigations

• Serum calcium and phosphate are normal but serum alkaline phosphatase is markedly high.

• X-rays: the involved bone is expanded and denser than normal.

Multiple fractures may be present in long bones.

A bone scan can detect the disease even before any x-ray changes are apparent.

Complications

• Fractures on minimal trauma.

• Kidney stones if there is immobilization.

• Spinal cord compression due to vertebral collapse.

• Osteosarcoma in long-standing cases.

• High output cardiac failure due to increased vascularity.

• Cranial nerve palsies and stroke due to skull involvement.

Management

– Refer to endocrinologist

• Bisphosphonates

• Calcitonin