Screening for osteoporosis in the adult U.S. population: ACPM position statement on preventive practice

Characterization of osteopenia/osteoporosis in adult scoliosis: does bone density affect surgical outcome?

STUDY DESIGN

Retrospective study.

OBJECTIVE

The aim of this study is to validate the prevalence of low bone mineral density (BMD) in woman patients with adult scoliosis and to relate that to surgical treatment outcome. Despite reports of the high prevalence of low BMD among female with adolescent idiopathic, these findings have not been substantiated in any comprehensive review of adult scoliosis patients undergoing surgical treatment.

SUMMARY OF BACKGROUND DATA

It has been suggested that scoliosis may predispose to osteoporosis and that degenerative scoliosis could falsely elevate spinal BMD measurements with dual energy radiograph absorptiometry (DXA). The discordance between hip and spine BMD measurement using DXA has also been shown in previous cross-sectional study for adult population.

METHODS

A retrospective review of 176 women treated surgically for scoliosis. BMD of the lumbar spine and femoral neck were determined by DXA. Patients were categorized as follows: concordance (osteoporosis, osteopenia, or normal BMD on both sites), minor discordance (osteoporosis in one site and osteopenia in the other site), and major discordance (osteoporosis in one site and normal the other site). Body mass index (BMI), preoperative Cobb angle, fusion ratio, and complication were recorded. Statistical analysis included the Student t test, χ(2) test, regression coefficient test, and simple linear regression. P value was set at P < 0.05.

RESULTS

The mean age was 51 ± 12 years (26-82 years). The mean T score of the hip was -1.23 ± 0.89 and of the spine was -0.52 ± 1.57. Major discordance in BMD 7 (4%) points, minor discordance 68 (39%) points, and concordance was 101 (57%) points. There was moderate correlation between T score of hip and spine (R = 0.55P < 0.01). T score of the hip and of the spine showed 10.8% and 10.2% of the patients were osteoporotic. The mean Z score of the hip and of the spine showed comparable age and sex matched values. No correlation was observed between BMD and Cobb angle (R = 0.05, P = 0.464). The fusion rate was 93% and surgical complication rate was 14.9%. No significant correlation was observed between BMD and fusion (P = 0.80) complication (P = 0.13).

CONCLUSION

Comparable bone density exists among adult scoliosis patients with no correlation between BMD and curve magnitude, fusion and complication rates. The difference in BMD of the hip and of spine cannot be fully explained in the review. These results will guide in surgical planning, patient selection on the treatment options.

Evaluation of a pulsed phase-locked loop system for noninvasive tracking of bone deformation under loading with finite element and strain analysis

Ultrasound has been widely used to nondestructively evaluate various materials, including biological tissues. Quantitative ultrasound has been used to assess bone quality and fracture risk. A pulsed phase-locked loop (PPLL) method has been proven for very sensitive tracking of ultrasound time-of-flight (TOF) changes. The objective of this work was to determine if the PPLL TOF tracking is sensitive to bone deformation changes during loading. The ability to noninvasively detect bone deformations has many implications, including assessment of bone strength and more accurate osteoporosis diagnostics and fracture risk prediction using a measure of bone mechanical quality. Fresh sheep femur cortical bone shell samples were instrumented with three 3-element rosette strain gauges and then tested under mechanical compression with eight loading levels using an MTS machine. Samples were divided into two groups based on internal marrow cavity content: with original marrow, or replaced with water. During compressive loading ultrasound waves were measured through acoustic transmission across the mid-diaphysis of bone. Finite element analysis (FEA) was used to describe ultrasound propagation path length changes under loading based on µCT-determined bone geometry. The results indicated that PPLL output correlates well to measured axial strain, with R(2) values of 0.70 ± 0.27 and 0.62 ± 0.29 for the marrow and water groups, respectively. The PPLL output correlates better with the ultrasound path length changes extracted from FEA. For the two validated FEA tests, correlation was improved to R(2) = 0.993 and R(2) = 0.879 through cortical path, from 0.815 and 0.794 via marrow path, respectively. This study shows that PPLL readings are sensitive to displacement changes during external bone loading, which may have potential to noninvasively assess bone strain and tissue mechanical properties.

Glucocorticoid-induced osteoporosis in men

Osteoporosis and fractures are a common consequence of glucocorticoid therapy for inflammatory disorders. Men fracture approximately 10 yr later in life than women and receive less attention as regards osteoporosis risk, including in glucocorticoid-induced osteoporosis (GIOP). In addition, while men are less likely to have certain rheumatologic disorders often treated with glucocorticoids, men are more likely to have chronic obstructive pulmonary disease, inflammatory bowel disease, and organ transplantation as reasons for use of oral glucocorticoids. Attempts to improve recognition of GIOP in general have not been successful, and since men are considered less at risk for osteoporosis in general, attention to men with GIOP is even less. Evaluation of GIOP is similar in men and women, and most modern treatment studies of GIOP have included men. Thus, alendronate, risedronate, and zoledronic acid are Food and Drug Administration (FDA)-approved bisphosphonates for GIOP in men. Teriparatide is also FDA-approved for GIOP. In one 36-month trial of teriparatide vs alendronate for GIOP in men and women, the anabolic agent led to a greater increase in bone density and was associated with a lower incidence of morphologic vertebral fractures. Thus, while good management is available for GIOP, recognition of men at risk is the most important step in improving outcomes.

Skeletal health in men with chronic lung disease: rates of testing, treatment, and fractures

To advance our understanding of the burden of fractures among men, we studied a group of men at high risk for low bone strength due to lung disease. We found high rates of fractures but low rates of bone density testing that could predict fracture before it occurs.

INTRODUCTION

To advance understanding of the burden of fragility fractures and attention to bone health among men with chronic obstructive lung disease (COPD), we quantified rates of fragility fracture, bone density testing, and anti-resorptive treatment and calculated the number needed to screen (NNS) to prevent one hip fracture in a cohort of men with COPD.

METHODS

Veterans Administration (VA) and VA-Medicare administrative data permitted a retrospective cohort study of 87,360 men aged 50 and older, newly diagnosed with COPD between 1999 and 2003. Logistic regression models including patient characteristics, morbidities, and medication use assessed the effect of covariates on fracture and probability of testing or treatment.

RESULTS

Mean age was 66.8. Hip and wrist fracture rates were 3.99 and 1.31 per 1,000 person years, respectively. Mean follow-up was 2.67 years; 4.4% underwent bone densitometry; 2.8% filled anti-resorptive prescriptions. Age, white race/ethnicity, more COPD exacerbations, barbiturate use, and anti-Parkinson's drug use were significantly associated with fracture. Age, and systemic corticosteroids were most significantly associated with testing or treatment. Based on published adherence and treatment effects, the cohort's calculated NNS to prevent one hip fracture is 432.

CONCLUSIONS

Fracture rate was high and testing and treatment uncommon. The NNS of 432 to prevent one hip fracture is smaller than 731, the NNS for women aged 65-69 for whom universal screening is recommended. Attention to the bone health of this population is warranted. Future research must determine how testing and treatment impact overall quality of life and mortality of men with COPD.

Prevalence of risk factors for fractures and use of DXA scanning in Danish women. A regional population-based study

SUMMARY

To determine the relationship between risk factors and use of DXA scans. Our study showed a relatively high use of DXA in low-risk women and the relatively low coverage in women with multiple risk factors. Moreover, distance to DXA clinics, age, and socio-economic factors are associated with the use of DXA.

INTRODUCTION

To determine the relationship between risk factors for fracture and use of DXA scans in Danish women in relation to distance to DXA clinics and socio-economic factors.

METHODS

From the Danish National Civil Register we randomly selected 5,000 women aged 40-90 years living in the region of Southern Denmark to receive a mailed questionnaire concerning risk factors for fractures.

RESULTS

The respondents rate was 84% and 77% of the invited population were available for analysis. A total of 10.3% of the women without risk factors and only 36% of the women with three or more risk factors had a history of DXA. The likelihood of a history of DXA was higher with increasing FRAX(™) 10-year risk; i.e., 8.7% and 30.2% in patients with a 10-year fracture risk of 0-14.9% and 25-100%, respectively. In women with less than 10 km to nearest DXA facility, 20.2% had a history of DXA, while 11.5% of those with more than 40 km to the nearest scanner had a history of DXA. Logistic regression analysis showed that distance, fracture risk, oral glucocorticoids, low-energy fracture, conditions associated with secondary osteoporosis, low BMI, history of falls, age 65-79 years, spouse status, and income were significantly associated with having a history of DXA.

CONCLUSIONS

Our study showed a relatively high use of DXA in low-risk women and the relatively low coverage in women with multiple risk factors. Moreover, distance to DXA clinics, age, and a number of socio-economic factors are associated with the use of DXA.

The Fracture Risk Assessment Tool (FRAX®): applications in clinical practice

Osteoporosis is a serious health concern affecting millions of Americans, with many patients going undiagnosed and untreated. Fractures due to osteoporosis and fracture-related complications are the most clinically relevant and costly consequences of this disorder. The Fracture Risk Assessment Tool (FRAX®), released by the World Health Organization (WHO) in February 2008, is a major achievement in helping determine which patients may be candidates for pharmacological therapy for osteoporosis. This Web-based algorithm, which has been incorporated into some dual x-ray absorptiometry (DXA) reporting software, calculates the 10-year probability of major osteoporotic fracture (clinical vertebral, hip, forearm, or humerus) and the 10-year probability of hip fracture in men and women based on easily obtained clinical risk factors and bone mineral density (BMD) of the femoral neck (optional). The National Osteoporosis Foundation updated its U.S. guidelines in February 2008 to incorporate FRAX and recommends that all postmenopausal women and men aged ≥50 years with a hip or vertebral fracture, a T-score ≤-2.5 at the femoral neck or spine (excluding secondary causes), or low bone mass (T-score between -1.0 and -2.5) and a 10-year probability of hip fracture ≥3% or of major osteoporosis-related fracture ≥20% (based on FRAX) should be considered candidates for drug therapy. Despite its demonstrated clinical utility, FRAX has limitations and should not be used in all situations. Acceptance and clinical use of FRAX may help identify men and women at increased risk for osteoporotic fracture, but implementing the tool into clinical practice may be a challenge for busy physicians.

EMAS position statement: Bone densitometry screening for osteoporosis

INTRODUCTION

Osteoporosis and its consequent fractures is a major public health problem.

AIM

To formulate a position statement on the use of bone densitometry in screening postmenopausal women for osteoporosis and in their management.

MATERIALS AND METHODS

Literature review and consensus of expert opinion.

RESULTS AND CONCLUSIONS

Bone densitometry has an important role in screening postmenopausal women for osteoporosis. For higher sensitivity and specificity, there may be a stronger case for screening in later life, depending on the extent to which risk factors add to the value of bone mineral density tests.

Reactive oxygen species on bone mineral density and mechanics in Cu,Zn superoxide dismutase (Sod1) knockout mice

Reactive oxygen species (ROS) play a role in a number of degenerative conditions including osteoporosis. Mice deficient in Cu,Zn-superoxide dismutase (Sod1) (Sod1(-/-) mice) have elevated oxidative stress and decreased muscle mass and strength compared to wild-type mice (WT) and appear to have an accelerated muscular aging phenotype. Thus, Sod1(-/-) mice may be a good model for evaluating the effects of free radical generation on diseases associated with aging. In this experiment, we tested the hypothesis that the structural integrity of bone as measured by bending stiffness (EI; N/mm(2)) and strength (MPa) is diminished in Sod1(-/-) compared to WT mice. Femurs were obtained from male and female WT and Sod1(-/-) mice at 8months of age and three-point bending tests were used to determine bending stiffness and strength. Bones were also analyzed for bone mineral density (BMD; mg/cc) using micro-computed tomography. Femurs were approximately equal in length across all groups, and there were no significant differences in BMD or EI with respect to gender in either genotype. Although male and female mice demonstrated similar properties within each genotype, Sod1(-/-) mice exhibited lower BMD and EI of femurs from both males and females compared with gender matched WT mice. Strength of femurs was also lower in Sod1(-/-) mice compared to WT as well as between genders. These data indicate that increased oxidative stress, due to the deficiency of Sod1 is associated with decreased bone stiffness and strength and Sod1(-/-) mice may represent an appropriate model for studying disease processes in aging bone.

The impact of frailty in the elderly on the outcome of surgery in the aged

As the population continues to age, we will continue to encounter issues involving aging and the elderly. Despite these issues, knowledge is expanding and evolving with new solutions to ongoing problems. Mechanistically, frailty at its root is a symptom of growing old, with cascades and circuitous feedback between organ systems at all levels. Clinically, frailty is as equally dynamic and its multifactorial nature represents a unique challenge to the surgical community and warrants the integration of geriatric assessment into clinical practice. Integration within clinical practice includes using an interdisciplinary approach, where surgeons work with anesthesiologists, geriatricians, nursing, rehabilitation, nutritionists, and other support staff to provide holistic assessment, efficient delivery, and higher quality of care. This in hand, recognition of frailty can occur in a timely fashion to initiate treatment, decreasing the risk of morbidity and mortality for improved surgical outcomes.

Current and emerging therapies for the treatment of osteoporosis

Osteoporosis represents a weakening of bone tissue due to an imbalance in the dynamic processes of bone formation and bone resorption that are continually ongoing within bone tissue. Most currently available osteoporosis therapies are antiresorptive agents. Over the past decade, bisphosphonates, notably alendronate and risedronate, have become the dominant agents with newer bisphosphonates such as ibandronate and zoledronic acid following a trend of less frequent dosing regimens. Synthetic estrogen receptor modulators (SERMs) continue to be developed as drugs that maintain the bone-protective effects of estrogen while avoiding its associated adverse side effects. Currently available agents of this class include raloxifene, the only SERM available in the United States (US), and lasofoxifene and bazedoxifene, available in Europe. Calcitonin, usually administered as a nasal spray, completes the list of currently approved antiresorptive agents, while parathyroid hormone analogs represent the only anabolic agents currently approved in both the US and Europe. Strontium ranelate is an additional agent available in Europe but not the US that has both anabolic and antiresorptive activity. New agents expected to further expand therapeutic options include denosumab, a monoclonal antibody inhibitor of the resorptive enzyme cathepsin K, which is in the final stages of Food and Drug Administration approval. Other agents in preclinical development include those targeting specific molecules of the Wnt/β-catenin pathway involved in stimulating bone formation by osteoblast cells. This review discusses the use of currently available agents as well as highlighting emerging agents expected to bring significant changes to the approach to osteoporosis therapy in the near future.

Bone fractures after menopause

BACKGROUND

Every year 30% of individuals above age 65 fall, and falls are the principal cause of bone fractures. To reduce fracture incidence requires both prevention of falls and maintenance of bone strength.

METHODS

PubMed searches were performed, for studies of the epidemiology of fractures, bone physiology, endocrine effects, osteoporosis measurement, genetics, prevention and effectiveness. Topic summaries were presented to the Workshop Group and omissions or disagreements were resolved by discussion.

RESULTS

Ageing reduces bone strength in post-menopausal women because estrogen deficiency causes accelerated bone resorption. Bone mineral density (BMD) decreased more than 2.5 standard deviation below the mean of healthy young adults defines osteoporosis, a condition associated with an increased risk of fractures. Risk factors such as age and previous fracture are combined with BMD for a more accurate prediction of fracture risk. The most widely used assessment tool is FRAX™ which combines clinical risk factors and femoral neck BMD. General preventive measures include physical exercise to reduce the risk of falling and vitamin D to facilitate calcium absorption. Pharmacological interventions consist mainly in the administration of inhibitors of bone resorption. Randomized controlled trials show treatment improves BMD, and may reduce the relative fracture risk by about 50% for vertebral, 20-25% for non-vertebral and up to 40% for hip fractures although the absolute risk reductions are much lower.

CONCLUSIONS

Although diagnosis of osteoporosis is an important step, the threshold for treatment to prevent fractures depends on additional clinical risk factors. None of the presently available treatment options provide complete fracture prevention.

A perspective on male osteoporosis

Osteoporosis and fragility fracture become common with advancing age in men. The incidence of osteoporosis-related fracture is similar to myocardial infarction and exceeds that of lung and prostate carcinoma combined. These fractures cause substantial morbidity, and the mortality following hip fracture is greater in men than in women. A decline in sex steroids and glucocorticoid and alcohol use, among other factors, contribute to bone loss and fracture risk. Approaches to reduce fracture risk in men are very similar to that in women - recognising and addressing muscle weakness/falls risk and optimising nutrition, with emphasis on calcium and vitamin D and medications when appropriate. Despite the high prevalence, osteoporosis remains largely undiagnosed and undertreated. Hopefully, increased recognition of male osteoporosis by health-care providers and the men themselves, in combination with recent consensus recommendations for treatment based on fracture-risk estimation, will reduce the burden of fragility fracture in men.

Long-term therapy in COPD: any evidence of adverse effect on bone?

Patients with COPD have high risk for osteoporosis and fractures. Hip and vertebral fractures might impair mobility, and vertebral fractures further reduce lung function. This review discusses the evidence of bone loss due to medical treatment opposed to disease severity and risk factors for COPD, and therapeutic options for the prevention and treatment of osteoporosis in these patients. A review of the English-language literature was conducted using the MEDLINE database until June 2009. Currently used bronchodilators probably lack adverse effect on bone. Oral corticosteroids (OCS) increase bone resorption and decrease bone formation in a dose response relationship, but the fracture risk is increased more than reflected by bone densitometry. Inhaled corticosteroids (ICS) have been associated with both increased bone loss and fracture risk. This might be a result of confounding by disease severity, but high doses of ICS have similar effects as equipotent doses of OCS. The life-style factors should be modified, use of regular OCS avoided and use of ICS restricted to those with evidenced effect and probably kept at moderate doses. The health care should actively reveal risk factors, include bone densitometry in fracture risk evaluation, and give adequate prevention and treatment for osteoporosis.

Triage screening for osteoporosis in dental clinics using panoramic radiographs

Many patients with osteoporosis go undiagnosed because typically no symptoms are present before a fracture. Triage screening to refer patients to appropriate medical professionals for further investigation would be useful to address the increase in the incidence of osteoporotic fractures. Dental clinics may offer a new triage screening pathway because dentists frequently take radiographs of bones in the course of dental treatment. A major premise for such triage screening in dental clinics is that dentists can readily use a screening tool in their dental practice. For example, cortical width and shape of the mandible detected on panoramic radiographs may be appropriate indices for triaging individuals with osteoporosis. To date, several investigators have demonstrated significant associations between cortical indices on panoramic radiographs and bone mineral density of the skeleton generally, such as the spine and femur, biochemical markers of bone turnover and risk of osteoporotic fractures. Further, in two recent Japanese clinical trials, approximately 95% of women who were identified by trained dentists in their clinics using cortical shape findings did have osteopenia or osteoporosis. These findings support the possibility that dental clinics may offer a new triage platform to identify individuals with otherwise undetected osteoporosis.