Instructional Course Lectures, The American Academy of Orthopaedic Surgeons - Osteoporosis

Abstract

Osteoporosis is characterized by decreased bone mass and increased susceptibility to fracture. Primary osteoporosis is defined as osteoporosis that occurs in an individual who has no endocrinopathy or other disease state that would account for the changes in bone mass. Osteoporosis affects 20 million individuals in the United States1. These individuals sustain more than 1.2 million fractures (including more than 280,000 fractures of the hip) annually; the estimated cost of treatment of such fractures was $10 billion in 19921,112. The absolute number and percentage of persons who have osteoporosis are expected to increase because of the prolonged longevity of the American population. The risk of a fracture of the proximal part of the femur increases with age, especially in women who are more than fifty years old92. Fractures of the proximal part of the femur are associated with a high rate of mortality, and most persons who have sustained such a fracture never regain their previous level of function72. Emotional morbidity in the form of depression, reclusiveness, and fear of additional fracture may accompany osteoporosis. Advances in our understanding of the etiology and pathophysiology of osteoporosis, as well as progress in the prevention and treatment of this disease, have given the physician the ability to intervene successfully. Riggs and Melton classified primary osteoporosis on the basis of the patterns of bone loss and fracture111. Postmenopausal (type-I), or osteoclast-mediated, osteoporosis is characterized by rapid bone loss and is seen most often in recently postmenopausal women (it affects women six times more frequently than men). This pattern is consistent with high-turnover osteoporosis. There is a rapid phase of bone loss predominantly involving trabecular bone and an association with vertebral and distal radial fractures. Senile (type-II), or osteoblast-mediated, osteoporosis affects women …