Porth's Essentials of Pathophysiology, 4e

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Musculoskeletal Function

U N I T 1 2

Decrease in height

Dowager hump

Predisposition to fractures

commonly referred to as dowager hump. Usually, there is no generalized bone tenderness. When pain occurs, it usually is related to fractures. Systemic symptoms such as weakness and weight loss suggest that the osteoporo- sis may be caused by underlying disease. Diagnosis and Treatment. An important advance in diagnostic methods used for the identification of osteo- porosis has been the use of BMD assessment. 20–22 The clinical method of choice for BMD studies is dual- energy x-ray absorptiometry (DEXA) of the spine and hip. Measurement of serial heights in older adults is another simple way to screen for osteoporosis. A further advance in the diagnosis of osteoporosis is the refine- ment of risk factors, permitting better analysis of risk pertaining to particular persons. The U.S. Preventive Services Task Force (USPSTF) recommends a screening DEXA of all women 65 years of age and older, as well as women 60 to 64 years of age who have an increased fracture risk. 23 Although there are no USPSTF guidelines for BMD testing in men, the National Osteoporosis Foundation (NOF) recommends screening for all men 70 years of age and older and men 50 to 69 years of age with risk factors. 22 Prevention and early detection of osteoporosis are essential to the prevention of associated deformities and fractures. It is important to identify persons in high-risk groups so that preventive measures can begin early (see Chart 44-1). Regular exercise and adequate calcium and vitamin D intake are important factors in preventing osteoporosis. Weight-bearing exercises such as walking, jogging, rowing, and weight lifting are important in the maintenance of bone mass. Studies have indicated that premenopausal women need more than 1000 mg/day of calcium, and postmenopausal women need at least 1200 mg of calcium daily. 20,22 Because most older American FIGURE 44-1. Osteoporosis. Femoral head of an 82-year- old woman with osteoporosis and femoral neck fracture (right), compared with a normal control bone cut to the same thickness (left). (From Garcia RA, Klein MJ, Schiller AL. Bones and joints. In: Rubin R, Strayer DS, eds. Rubin’s Pathology: Clinicopathologic Foundations of Medicine. 6th ed. Philadelphia, PA: Wolters Kluwer Health | Lippincott Williams & Wilkins; 2012:1226.)

Fracture of distal radius

Compression fracture of vertebrae

Fractured hip

FIGURE 44-2. Clinical manifestations of osteoporosis.

women do not consume a sufficient quantity of dairy products to meet their calcium needs, calcium supple- mentation is recommended. A daily intake of 800 to 1000 IU of vitamin D is recommended for adults age 50 years and older. Many elderly persons are at high risk for vitamin D deficiency, especially those with chronic illness, malabsorption disorders (e.g., celiac disease), and limited exposure to sunlight. It is recommended that serum vitamin D levels be obtained for persons at risk of a deficiency and that supplemental vitamin D be pre- scribed for persons with low serum levels. 22 There are five main types of drugs used in the treat- ment of osteoporosis: bisphosphonates, selective estrogen receptor modulators (SERMs), calcitonin, recombinant parathyroid hormone, and the RANKL inhibitor denosumab. 24 Bisphosphonates are effective inhibitors of bone resorption and the most effective agents for prevention and treatment of osteoporosis. The bisphosphonates (e.g., alendronate, risedronate, ibandronate, zoledronate) are analogs of endogenous inorganic pyrophosphate that the body cannot break down. In bone, they bind to hydroxyapatite and prevent