Faculty Bibliography

The past year has been a dynamic one for clinicians and researchers with an interest in osteoporosis. This update will focus on the issue of the relationship between bisphosphonate treatment and atypical femoral fractures, highlight the advances in imaging techniques that are increasingly being studied as adjuncts to bone density testing, and explore re- cent evidence that suggests that osteoporosis medications may be linked to an increase in life expectancy. Since the first case reports describing unusual femur fractures in long term users of bisphosphonates began to appear, there has been great interest in identifying why and whether this class of drug can cause these atypical fractures. There have been a significant number of large studies that seem to suggest that these fractures do occur with an increased frequency among subjects who have used bisphosphonates over an extended period of time, but that these events are relatively rare. The occurrence of these fractures have helped to fashion new treatment regimens with periods of "drug holidays" often recommended to people with lower short-term and intermediate-term fracture risk. It is important to remind the reader that bisphosphonates prevent many typical hip and vertebral compression fractures, particularly in the higher risk elderly patient and that a rational balance be struck so that those in need of continued osteoporosis treatment receive it. Advances in imaging, such as high resolution MRI and peripheral micro CT scanners, are allowing investigators to non-invasively assess bone microarchitecture and bone stiffness of individuals as a means of trying to more accurately define those subjects who might be at increased risk of fracture and who might benefit from bone strengthening medication. Finally, this update will briefly review the emerging data that suggests that anti-resorptive medication may extend life expectancy beyond that which can be expected solely by reducing the incidence of future fractures.

With the aging of the population, low bone mass states will be an increasing clinical issue for both men and women. More than 2 million osteoporotic fractures occur annually in the United States and it is estimated that nearly half of American Caucasian women over the age of 50 will experience at least one fragility fracture in their lifetime. Identifying subjects at increased risk for fracture and defining rational treatment strategies that balance risks with therapeutic benefits promises to be a major focus in the decade ahead. This review focuses on several areas of active interest in osteoporosis including the use of fracture assessment tools that help quantify time sensitive fracture risks by using patient specific data, advances in bone imaging and the relationship between structure and strength, new and future drug treatments for osteoporosis, and several unusual adverse clinical syndromes linked to the use of bisphosphonates. The topics chosen for this review highlight the increased understanding of bone structure and aging and how this knowledge can help clinicians in their treatment of osteoporosis

Regional migratory osteoporosis (RMO) is a rare, self-limited disease of unknown etiology, characterized by migratory arthralgia of the weight-bearing joints of the lower extremities. RMO is most commonly seen in middle-aged adults, particularly men. Several case reports suggest that bone changes seen in RMO may be detected as focal decreases in bone mineralization, but the utility of serial bone density studies has yet to be formally evaluated in this syndrome. We describe a case of RMO with dramatic focal changes in bone mineral density that corresponded to the underlying clinical course. Serial bone density testing clearly documented significant bone loss and subsequent recovery of bone density in areas affected by RMO. Our data suggest that sequential densitometric examination of affected areas may be useful to confirm the diagnosis of RMO, and for subsequent monitoring of bone loss and therapeutic response

The need to initiate treatment for a postmenopausal woman with a low bone mass should be based on that individual's fracture risk over a fnite period of time. Fracture assessment tools, such as the recently introduced FRAX(TM) model, allows the clinician to estimate an individual's absolute fracture risk over the next decade of their life. Such estimates are particularly useful for younger postmenopausal females with bone density values in the osteopenic range. Fracture risk increases with age and is inversely related to bone mineral density values. A history of previous fracture after the age of 45 and within 10 years of assessment increases subsequent fracture risk

Estimating an individual's fracture risk is the most significant factor for determining the need to initiate bone strengthening treatment in the postmenopausal woman. Fracture risk in inversely and most strongly related to an individual's bone mineral density values, but other factors including age, prior fracture history, body mass index, general health, family history of fractures, corticosteroid use, and smoking history also influence the risk of subsequent fractures. Fracture risk assessment tools such as the World Health Organization's FRAX tool and the Study of Osteoporotic Fractures Index provide 10- and 5-year fracture probability estimates, respectively, and using these tools can be particularly helpful in assessing the immediate need to initiate treatment in younger postmenopausal women. Perimenopausal and postmenopausal bone loss averages about 1% per year with more annual bone loss occurring in trabecular than cortical bone and during a normal life span such bone loss can exceed 35% of an individual's bone mass. Younger postmenopausal women with low bone mineral density values, a history of a previous fracture, greater rates of bone loss as measured by bone turnover markers are more likely to need bone strengthening treatment at an earlier age in the postmenopausal period. Treatment measures include adequate amounts of dietary and supplemental calcium and vitamin D, a routine of regular exercises and medications that reduce the rate of new fractures

PURPOSE OF REVIEW: The female athlete triad - anorexia, athletics, and amenorrhea - is a clinical problem found among young women who are engaged in intense physical activity. This review describes the psychological factors involved in the triad and the endocrine and skeletal consequences of the disorder. This subject is particularly timely and important as eating disorders are increasing in frequency among young women athletes. RECENT FINDINGS: Concern about body weight and its effect on athletic performance can lead to chronic undernutrition. Complications of low body weight include hormonal disturbances, bone loss and fracture. The potential endocrine abnormalities seen in this group of women include anovulatory cycles, chronic elevation in glucocorticoids and lower serum leptin concentrations. Lower insulin-like growth factor-1 and resistance to growth hormone have also been described. Treatment of consequent bone loss with hormones, and most recently, with bisphosphonates, provides conflicting, but also encouraging data. SUMMARY: The pressures to improve peak athletic performance often underlie the abnormal behavior and eating disorders characteristic of the female athlete triad, with subsequent life-long consequences. Physicians should be made aware of such pressures, and their psychological and physical consequences. Prevention is the best medicine; but more research in ways to effectively and safely treat bone loss in young women is needed