Paget Disease

• • Also known as osteitis deformans

  • Nonmalignant disease involving accelerated bone resumption followed by deposition of dense, disorganized, and ineffectively mineralized bone matrix

  • Etiology is unknown, although posited to be infectious; hereditary causes possible as well

  • 3 phases of disease:

  • -Intense bone resorption

    -Production of abundant woven bone with ineffective mineralization

    -Deposition of sclerotic, chaotic cortical and trabecular bone

Epidemiology

• • Second most common bone disorder, behind osteoporosis

  • Male:female ratio is 1:1

  • Affects 3% of persons in the United States

  • Affects 10% of persons older than 80 years

  • Up to 40% of patients have positive family history for Paget disease

  • 1-10% malignant degeneration of pagetic bones

Symptoms and Signs

• • Pain in the affected bone

  • Alteration in hearing and vision

  • Loosening of teeth (if jaw involvement)

  • Headaches

  • Damage to cartilage, with resultant arthritis

  • Nephrolithiasis

  • High output heart failure (from AV shunting in bone marrow)

  • Kyphosis

  • Frontal bossing

  • Leonine facies

Laboratory Findings

• • Elevated serum calcium

  • Elevated serum alkaline phosphatase

  • Elevated urine calcium

  • Elevated urinary pyridinoline

Imaging Findings

• • Soft-tissue masses and cortical breakthrough on plain x-rays suggest malignant transformation

  • Radiographs include both early lytic lesions and late sclerotic findings

• • Always consider metastatic disease to bone

• • Complete history (including family) and physical exam

  • Appropriate x-rays

  • Serum calcium, alkaline phosphatase, and urinary pyridinoline

• • Treatment does not cure but prolongs periods of remission

  • Goals should include aggressive pain control

Surgery

Indications

• • Progressive bowing of the tibia or femur

  • Delayed union of fractures

  • Unstable fractures

  • Arthritis refractory to medical treatment

  • Focal nerve compression of the spine or cranium

Medications

• • Bisphosphonates inhibit osteoclast resorption

  • Injectable calcitonin

Treatment Monitoring

• • Repeat radiographs, especially of weight bearing joints, to monitor degeneration

  • Serum alkaline phosphatase (from every 3 to 12 months)

Complications

• • Malignant degeneration into osteosarcomas, fibrosarcomas, or undifferentiated spindle cell sarcomas

References