Paget’s Disease (Osteitis Deformans)

– Chronic inflammatory disease of the bones that results in thickening, softening, and eventually bowing.

Causes and Incidence

The etiology is unknown, although a familial pattern has been noted and a viral link is suspected. Paget’s disease occurs worldwide but is more common in Europe, Australia, and New Zealand. About 2.5 million people are affected in the United States. Men are more likely to be affected, as are individuals over 40 years of age.

Disease Process

The disease begins with an initial phase of excessive bone resorption followed by a reactive phase of excessive and abnormal bone formation. The result is large, multinucleated osteoblasts; thickened lamellae and trabeculae; and fibrotic tissue, which produces enlarged, weakened, heavily calcified bone.

Symptoms

Early disease is asymptomatic, with an insidious onset of aching, deep pain; stiffness; fatigability; headaches; and decreased hearing. Later signs include bowing and other bone deformities, such as an increasing skull size. Fractures occur with minor trauma.

Potential Complications

Complications include vertebral collapse and resulting paralysis; blindness, deafness, or vertigo from impingement on cranial nerves; vascular collapse from increased cardiac demands; gout; and renal calculi.

Diagnostic Tests

The diagnosis is often incidental to examinations done for other reasons. X-ray examination shows increased bone density, abnormal architecture, cortical thickening, bowing, and bony overgrowth. The serum alkaline phosphatase level is elevated. Radionuclide bone scans show increased nuclide uptake at affected sites.

Treatments

Surgery
Hip replacement; spinal decompression.

Drugs
Nonsteroidal antiinflammatory agents for pain; chemotherapy to suppress bone cell activity before surgery or to prevent complications in poor surgical candidates; calcitonin or etidronate to manage disease.

General
Orthoses for gait correction; balance of exercise and rest; referral to support groups.