The prevention of osteoporotic fractures

Osteoporosis and Spine Surgery: A Critical Analysis Review

Despite being part of the aging process, early and adequate management of osteoporosis mitigates adverse outcomes associated with low bone mineral density. Although the health-care burden of osteoporosis is on the rise, screening and management of osteoporosis are not yet an integral part of preoperative patient evaluation in spine surgery. Patients with osteoporosis should undergo multidisciplinary evaluation and management, including lifestyle modifications and initiation of multiple therapeutic modalities. Integrating osteoporosis in preoperative optimization and surgical planning for patients undergoing spine surgery has the potential to mitigate osteoporosis-related postoperative complications.

DXA reference values of the humanoid sheep model in preclinical studies

Background

Merino land sheep are a popular pre-clinical large animal model in research on systemic skeletal diseases such as osteoporosis. Interpretation of studies is difficult because many reference parameters are missing or not established. This study aims to determine the reference parameters of the skeletal system (peak bone mass = PBM, T-Score). A defined standard allows an easier comparison of the study data of the animal model with human studies (T-Score).

Materials and methods

A total of 116 Dual Energy X-ray Absorptiometry DXA measurements were performed on 74 untreated sheep. The average age of the animals was 57 months. The BMD, BMC, and fat content of the sheep were determined by the relevant human region of interest (ROI). From this, the PBM and from this the T-score for each of the animals were calculated.

Results

Using 682 DXA measurements BMD and BMC were determined to provide an indication to PBM. For BMD a significant correlation to the age of the animals was observed (p = 0.043). A significant correlation was also seen for BMC (B) (p ≤ 0.001). In the age-dependent analysis, a widespread of values above the linear regression line was measured for both BMD and BMC between the 50th and 90th months of life. From an age of about 90 months, a wider spread of values below the linear regression line was found, although the average values continued to rise.

Discussion

The evaluation of the 116 DXA measurements allowed the determination of the PBM for merino land sheep. With the help of the PBM, a T-score was calculated for each animal. The statistical analysis shows significant differences in BMD values between the different animal groups in each of the four ROIs investigated. Individual control or sham groups per study are therefore not sufficient. To improve comparability, an independent reference group should be established.

Conclusion

An independent reference group for PBM and a T-score was established from four to six-year-old animals. The bone density increases with the age of the animals. Around the fourth year of life, a first peak could be observed. Also, after the seventh year of life, a further peak with the beginning plateau phase was observed. When compiling a group of animals for an osteoporosis model, animals from the age of seven years should, therefore, be used.

A New Clinically Relevant T-Score Standard to Interpret Bone Status in a Sheep Model

Background

Osteoporosis is diagnosed by bone loss using a radiological parameter called T-score. Preclinical studies use DXA to evaluate bone status were the T-score is referenced on bone mineral density (BMD) values of the same animals before treatment. Clinically, the reference BMD represents values of an independent group of healthy patients around 30 years old. The present study established a clinically similar T-score standard to diagnose osteoporosis in a sheep model.

Material/Methods

We used 31 female merino land sheep (average 5.5 years old) to study osteoporosis. The following groups were compared using DXA measurement: 1) control; 2) ovariectomized (OVX); 3) OVX combined with a deficient diet (OVXD); and 4) OVXD combined with methylprednisolone administration (OVXDS). Further, an independent group of 32 healthy sheep (4–6 years old) were measured as an independent baseline. BMD was measured at 0 months, 3 months, and 8 months after treatment.

Results

The same significance pattern between the treated groups and either baseline groups was seen. However, using an independent baseline changed the “clinical” interpretation of the data from an osteoporotic bone status (T-score <−2.5) after 3 months of OXDS treatment into an osteopenic bone status (T-score <−1.5 to −2.4).

Conclusions

Using an independent baseline enhanced the statistical significance and showed the clinical relevance. Furthermore, an independent baseline is a reliable alternative to use of a new control group for future experiments and thus reduces the number of animals needed by eliminating the need for a control and corresponding to clinical practice.

Geriatric Patients With Fractures Below the Hip are Medically Similar to Geriatric Patients With Hip Fracture

The objective of this study was to compare a cohort of geriatric patients with operatively managed isolated fractures below the hip to a cohort of geriatric patients with operatively managed isolated hip fractures. All patients greater than 59 years of age admitted to our institution for surgical care of an isolated lower extremity fracture during a 3-year period were included. Patients were divided into 2 cohorts: BTH (fracture below the subtrochanteric region of the femur) and HIP (proximal femoral fracture at subtrochanteric region or proximal). We identified 141 patients included in cohort BTH and 205 patients included in cohort HIP. HIP patients were older (P < .01) and less obese (P < .01) but were otherwise very similar. An extensive comorbidity review revealed that the 2 cohorts were similar, with the exception of an increased incidence of dementia (P = .012) or glaucoma (P = .04) in HIP patients and of peripheral neuropathy (P = .014) in BTH patients. HIP patients were more likely to be under active antiosteoporotic medication management and were more likely to be receiving pharmacological anticoagulation at the time of admission. HIP patients and BTH patients were similar with regard to necessity of assistance with ambulation preinjury, but HIP patients were less likely to reside independently at home than were BTH patients (P < .001). HIP patients were also less likely to be discharged directly home from the hospital (P < .001). Geriatric patients with fractures below the hip are medically similar to geriatric patients with hip fracture. Medical comanagement protocols have been extensively published that improve care of geriatric patients with hip fracture; consideration should be given to similar protocol-driven medical comanagement programs for geriatric patients with fractures below the hip.

Nonsurgical Treatment Strategies after Osteoporotic Hip Fractures

Osteoporosis is a metabolic disease that is increasing in prevalence as people live longer. Because the orthopedic surgeon is frequently the first and often the only physician to manage patients with osteoporotic hip fractures, every effort should be made to prevent future fractures. A multidisciplinary approach is essential in treatment of osteoporotic fractures. Basic treatment includes calcium and vitamin D supplementation, fall prevention, hip protection, and balance and exercise programs. Currently available pharmacologic agents are divided into antiresorptive and anabolic groups. Antiresorptive agents such as bisphosphonates limit bone resorption through inhibition of osteoclastic activity. Anabolic agents such as parathyroid hormone promote bone formation.

Osteopontin in bone mineral density of very old Brazilians

Recent evidence suggests that changes in plasma levels of osteopontin (OPN) may be a promising marker for early diagnosis of bone disorders. We hypothesized that a frequent OPN gene polymorphism may be useful for identifying very old individuals with alterations in plasma OPN levels and consequently at risk of abnormal bone density scores. Men and women (80 years or older) living in the Brazilian Federal District underwent assessments with dual energy X-ray absorptiometry for bone mineral density (BMD) of the femoral neck, femoral head and lumbosacral (L1 to S5) regions. Clinical inspection was performed to assess other physical traits and to exclude co-morbidities (cardiovascular, autoimmunity, infections or neoplastic diseases). Serum concentrations of OPN were determined with an enzyme-linked immunosorbent assay, whereas the A7385G polymorphism (rs1126772) was determined by direct sequencing of a polymerase chain reaction product. Among the two hundred and ten subjects enrolled, no differential scores for bone mineral density could be observed across genotypes, but a greater content of circulating OPN was found among carriers of the A allele (P ≤ 0.05) even after adjustments. Serum OPN levels were negatively correlated with femoral neck density (P = 0.050 for BMD; P = 0.032 for T scores) but not with scores of the other regions investigated. Analyses with the sample dichotomized to age and body mass revealed that this inverse relationship was noticeable only among those aged within the highest and weighing within the lowest intervals. Our findings indicate elevated circulating osteopontin levels in patients with decreased bone mineral density, consistent with a modest contribution of an OPN allelic variation to its expression. Assessing the clinical relevance of our findings demands forthcoming studies.

Better Quality of Care or Healthier Patients? Hospital Utilization by Medicare Advantage and Fee-for-Service Enrollees

Do differences in rates of use among managed care and Fee-for-Service Medicare beneficiaries reflect selection bias or successful care management by insurers? I demonstrate a new method to estimate the treatment effect of insurance status on health care utilization. Using clinical information and risk-adjustment techniques on data on acute admission that are unrelated to recent medical care, I create a proxy measure of unobserved health status. I find that positive selection accounts for between one-quarter and one-third of the risk-adjusted differences in rates of hospitalization for ambulatory care sensitive conditions and elective procedures among Medicare managed care and Fee-for-Service enrollees in 7 years of Healthcare Cost and Utilization Project State Inpatient Databases from Arizona, Florida, New Jersey and New York matched to Medicare enrollment data. Beyond selection effects, I find that managed care plans reduce rates of potentially preventable hospitalizations by 12.5 per 1,000 enrollees (compared to mean of 46 per 1,000) and reduce annual rates of elective admissions by 4 per 1,000 enrollees (mean 18.6 per 1,000).

Functional outcome and mortality in geriatric distal femoral fractures

BACKGROUND

Fragility fractures are a major health care problem worldwide. Due to the ageing population an increase of distal femoral fractures is to be expected. We studied the long-term functional outcome and their influencing factors in geriatric patients with LISS-plated distal femoral fractures.

PATIENTS AND METHODS

A cohort study with functional long-term follow up examination was carried out in a level one trauma centre on distal femoral fracture patients 65 years and older. Of 53 consecutive patients who were treated in our hospital, 43 patients with a mean age of 80 years met our inclusion criteria. 48.8% died within the study period of 5.3 years. On the remaining patients the residential status, the Barthel index and the Parker score were assessed.

RESULTS

The mean Barthel index was 47.7 and the mean Parker score was 3.5. 23% were found to be totally housebound and 26% were not able to perform any social activity. Only 18% were able to walk unaided. Patients with any medical complication had significantly higher mortality rates. Patients with extraarticular fractures had better mobility scores. Nursing home residents showed higher mortality rates but compared to patients coming from their own home the difference regarding Barthel and Parker scores remained non-significant.

CONCLUSION

This study documents the poor functional long-term outcome of geriatric patients with distal femoral fractures. In comparison to other fragility fracture patients it seems that this population is at higher risk to die in-hospital during their perioperative course. Medical complications have to be avoided as they were found to be associated with worse functional outcome and higher mortality rates. An osteoporosis therapy may be associated with reduced mortality rates also in these patients.

Hip fracture management, before and beyond surgery and medication: a synthesis of the evidence

INTRODUCTION

The geriatrician and orthopedic surgeon's roles are well defined in hip fracture management, yet other health-care providers contribute significantly toward care, as well as maximizing rehabilitation potential and decreasing readmissions. We examine evidence concerning pre-hospital care, pain management, multidisciplinary rehabilitation and secondary prevention strategies.

METHODS

Cochrane reviews and randomized controlled trials were identified through PubMed to synthesize current evidence in the role of multidisciplinary management of the patient with a hip fracture from injury to secondary prevention. The well-recognized roles of the geriatrician, anesthetist and orthopedic surgeon were not evaluated for the purpose of this review.

RESULTS

Transport of patients with a hip fracture can be eased through non-pharmaceutical simple, inexpensive techniques. Nerve blockade appears effective and easily administered in the emergency department. In-hospital multidisciplinary rehabilitation programs are effective in both earlier discharge and reducing falls, morbidity and mortality. Fall prevention programs are effective in nursing home patients, but not community dwellers. Osteoporosis prevention is primarily a medical endeavor; however, exercise and education may contribute to increased bone mineral density, compliance and better results of treatment.

CONCLUSION

Multidisciplinary medical management of patients with hip fractures is being improved within the hospital environment resulting in earlier discharge with decreased morbidity. There is evidence to show the benefits to patients with hip fractures from peripheral modalities within the hospital; however unless resident in a facility, multidisciplinary management is not clearly of benefit.

Long-term functional outcome in geriatric hip fracture patients

BACKGROUND

Fragility fractures are a major health care problem worldwide. The proportion of the geriatric population and the overall life expectancy will increase. Hip fractures are the most common fragility fractures needing surgery and nowadays treatment concepts are changing. We studied the long-term functional outcome and their influencing factors in patients treated without any interdisciplinary aspects.

DESIGN AND SETTING

A retrospective cohort study with functional long-term follow-up examination was carried out in a level one trauma centre on hip fracture patients 80 years old and above treated without any formalized interdisciplinary aspects ("usual care").

PATIENTS

Of 281 consecutive patients who were treated 2005 and 2006 with usual care, 246 patients with a mean age of 86.8 years met our inclusion criteria. 69.1% died within the study period of 4.9 years. On the remaining patients, the residential status, the Barthel Index and the Parker Score were assessed.

RESULTS

The mean Barthel Index was 49.6 and the mean Parker Score was 2.7. More than one-fourth of the survivors were found to be bedridden and 45% were not able to walk outside. 88% are bound to one floor and only 8% are able to walk unaided. Patients with more comorbidities and patients with subsequent fractures had significant higher mortality rates. Patients with trochanteric fractures had significant better functional outcome scores compared to patients with femoral neck fractures. Nursing home residents showed significant higher mortality rates and lower functional outcome scores. Patients who were transferred to a nearby acute geriatric hospital for further treatment had significantly higher functional outcome scores.

CONCLUSION

This paper shows the frustrating long-term outcome of geriatric hip fracture patients but it also suggests that an early geriatric intervention may lead to better function.

Bone loading during young adulthood predicts bone mineral density in physically active, middle-aged men

BACKGROUND

Physical activity during growth induces skeletal adaptations that increase bone strength; however, it remains unclear whether these benefits persist into middle age.

OBJECTIVE

We sought to determine if bone loading during adolescence (ages 13-18 years) or young adulthood (ages 19-29 years) in men is associated with greater bone mineral density (BMD) and reduced risk of low bone density in adulthood. We also sought to determine if participation in high-impact activities (ie, those that produce a ground reaction force [GRF] > 4 times the individual's body weight] during adolescence and/or young adulthood has a lasting positive effect on adult BMD.

METHODS

Eighty-six, apparently healthy, physically active men (aged 30-60 years) participated in this cross-sectional study. Bone loading during adolescence, young adulthood, and adulthood were calculated based on GRFs of the reported physical activities. Whole body, lumbar spine, total hip, and femoral neck BMD were assessed using dual-energy x-ray absorptiometry (DXA). Multiple linear regression was used to examine relationships between BMD and bone loading, including body weight and/or age as covariates; logistic regression was used to predict low bone density for age. Participants were grouped based on participation in high-impact activity (never [n = 42], adolescence only [n = 19], or both adolescence and young adulthood [n=23]), and BMDs were compared.

RESULTS

Bone loading during young adulthood, but not adolescence, was a significant positive predictor of adult BMD, with the full models explaining 33.4%, 31.7%, 44.6%, and 50.6% of the variance in whole body, lumbar spine, total hip, and femoral neck BMD, respectively. Ten participants (11.6%) had low bone density for age based on z scores of the hip or spine. Body weight and lean body mass, but not bone loading, were associated with reduced risk of low bone density for age. Individuals who participated in high-impact activity during both adolescence and young adulthood had greater BMD at all measured sites compared with those participated only during adolescence.

CONCLUSION

The results of the study support a lifelong exercise prescription for bone health to preserve the skeletal benefits of activity derived from activity during adolescence and young adulthood.

Long-term voluntary exercise of male mice induces more beneficial effects on cancellous and cortical bone than on the collagenous matrix

The effects of lifelong physical exercise on the composition, structure and mechanical properties of bone are not well understood. Earlier, we found that voluntary physical exercise improved various properties of bone in maturing male mice up to 6 months of age. In this study, we extended the previous study to 18 months. Half of the mice (total N=144) had access to running wheels while half were kept sedentary. The collagen network was assessed biochemically and by tensile testing of decalcified bone. The mineralized femur was analyzed with pQCT and three-point-bending of the diaphysis and neck-strength-test. The proximal tibia was analyzed with microCT. The bone collagen revealed inferior tensional properties with aging and the mineralized femur demonstrated decreased stiffness with age. In the running mice, tensile properties and the BMD were reduced at 18 months of age compared to the sedentary mice. In contrast, the stiffness of both the diaphysis and femoral neck was higher, and trabecular architecture and structure were improved in the running mice. In summary, the results suggest that lifelong exercise training of male mice results in more beneficial effects on intact mineralized bone in both the diaphysis and epiphysis than on bone collagenous matrix.

Linkage of genes to total lean body mass in normal women

BACKGROUND

Total lean body mass (LEAN-tot) is one of the three major components of body weight. Its deterioration is a risk factor for frailty. Despite this, there are few studies examining the contribution of genetic factors.

OBJECTIVE

Our objective was to examine the contribution of genetic factors for LEAN-tot variation, including a genome-wide search for the genes.

RESEARCH METHODS

Dual-energy x-ray absorptiometry measurements of LEAN-tot were obtained from each of the 3180 United Kingdom females (509 monozygotic and 1081 dizygotic twin pairs). Contribution of genetic factors was assessed using variance component analysis. A genome-wide linkage analysis was performed on the dizygotic twins using a modified version of the Haseman-Elston method.

RESULTS

Age, body height, total fat, and bone mass were correlated with LEAN-tot, and commonly explained 52% of the LEAN-tot variation. The crude heritability estimate was 74.0 +/- 4.0%, after adjustment for the aforementioned factors; 65.2 +/- 4.6% was attributable to independent genetic effects. Significant (P < 0.001) genetic correlations were found between LEAN-tot and bone mass, and LEAN-tot and total fat. Adjusted only for age, LEAN-tot showed no significant linkage. After adjustment for all covariates, significant linkage (LOD = 4.49 and 3.62) was observed at chromosome 12q24.3 and 14q22.3, respectively. Additional peaks of interest were on 7p15.3-15.1 (LOD = 2.86) and 8p22 (LOD = 2.83).

CONCLUSIONS

LEAN-tot measured by dual-energy x-ray absorptiometry is highly heritable, independent of other body measures. This first genomic search for genes associated with the lean component of body mass suggests significant linkage to quantitative trait loci on chromosomes 12 and 14.

Factors affecting the risk of hip fractures

AIMS

Hip fractures constitute a major cause of morbidity and mortality among the elderly, and are associated with a considerable and increasing economic burden. It has been estimated that the worldwide annual number of hip fractures will increase to 6.26 million by year 2050. The purpose of the current article was to review the factors affecting the risk of hip fractures.

METHODS

Original data for inclusion in this systematic review were identified through a MEDLINE search of the literature.

RESULTS

Several factors seem to affect the risk of hip fracture. The effect of each individual factor on hip fracture risk can be considered moderate; however, their summation can cause a substantial impact.

CONCLUSION

Recognising and a better understanding of the factors affecting the risk of hip fracture could aid to the planning of prophylactic strategies for reducing the problem and help the elderly remain independent and have a higher quality of life in their late years.