Osteoporosis

 OSTEOPOROSIS 

Osteoporosis is decreased bone mass (osteopenia), resulting in thin, fragile bones susceptible to fracture. It is the most common bone disorder in the United States. It most commonly occurs in postmenopausal Caucasian women and the elderly.

Primary causes of osteoporosis include the following:

• Estrogen deficiency (postmenopausal, Turner syndrome)

• Genetic factors (low density of original bone)

• Lack of exercise

• Old age

• Nutritional factors

 

Secondary causes include immobilization, endocrinopathies (e.g., Cushing disease, thyrotoxicosis), malnutrition (e.g., deficiencies of calcium, vitamins C and D, protein), corticosteroids, smoking/alcohol consumption, genetic disease (e.g., Gaucher disease).

 

• Patients may experience bone pain and fractures; weight-bearing bones are predisposed to fractures.

• Common fracture sites include vertebrae (compression fracture); femoral neck (hip fracture); and distal radius (Colles fracture).

• Kyphosis and loss of height may result.

• X-rays show generalized radiolucency of bone (osteopenia).

 

Dual-energy x-ray absorptiometry (DEXA) can measure bone mineral density to

predict fracture risk. Lab studies may show normal serum calcium, phosphorus, and alkaline phosphatase, but the diagnosis is not based on labs. Microscopically, the bone has thinned cortical and trabecular bone.

 

Treatment can include estrogen replacement therapy (controversial; not recommended currently); weight-bearing exercise; calcium and vitamin D; bisphosphonate (alendronate); and calcitonin.