Osteoporosis: disease severity and consequent fracture management

Risk of bony endplate failure during vertebral fracture

The endplate region of the vertebra, which includes the bony endplate (BEP) and underlying subchondral trabecular bone (STB), is critically involved in vertebral fracture (VF). While evidence abounds that failure initiates in the endplate region, the relative risk of failure of the BEP vs. STB has not been established. In this study, micro-finite element models were constructed of L1 vertebrae (n = 21) that were mechanically tested in a prior study and given experimentally matched boundary conditions corresponding to the vertebra's yield point. Volumes of interest (VOIs) were defined corresponding to the BEP and STB; the remainder was defined as the mid-vertebral body (MVB). The proportion of elements within each VOI that yielded was defined as the VOI yield fraction, and this value divided by the yield fraction of the entire model was defined as the normalized yield fraction. While yield fraction did not differ across VOIs (p = 0.179), normalized yield fraction was greater in the BEP than STB and MVB (p < 0.001), indicating a higher risk of yield in the BEP compared to the other two VOIs. None of the yield fractions was correlated with BEP or STB microstructure, and tension (rather than compression) was the dominant mode of tissue level yield. These findings indicate that the BEP, more so than the STB, is likely the site of VF initiation and that current methods of screening for VF risk, because they omit specific analysis of the BEP, are missing the region that matters the most. The endplate region of the vertebra, which includes the bony endplate (BEP) and underlying subchondral bone (SB), is critically involved in vertebral fracture (VF). While evidence abounds that failure initiates in the endplate region, the relative risk of failure of the BEP vs. SB has not been established. In this study, micro-finite element models were constructed of L1 vertebrae (n = 21) that had been mechanically tested in a prior study, and they were given experimentally matched boundary conditions corresponding to the vertebra's yield point. Volumes of interest (VOIs) were defined corresponding to the BEP and SB; the remainder was defined as the mid-vertebral body (MVB). The proportion of yielded elements within each VOI was defined as the VOI yield fraction, and this value divided by the yield fraction of the entire model was defined as the normalized yield fraction. While yield fraction did not differ across VOIs (p = 0.179), normalized yield fraction was greater in the BEP than SB and MVB (p < 0.001), indicating a higher risk of yield in the BEP compared to the other two VOIs. None of the yield fractions was correlated with BEP or SB microstructure, and tension (rather than compression) was the dominant mode of tissue level yield. These findings indicate that the BEP, more so than the SB, is likely the site of VF initiation and that current methods of screening for VF risk, because they omit specific analysis of the BEP, are missing the region that matters the most.

The utility of Hibiscus sabdariffa L. to prepare metal oxides NPs for clinical application on osteoporosis supported by theoretical study

Green synthesis of metal oxides as a treatment for bone diseases is still exploring. Herein, MgO and Fe2O3 NPs were prepared from the extract of Hibiscus sabdariffa L. to study their effect on vit D3, Ca+2, and alkaline phosphatase enzyme ALP associated with osteoporosis. Computational chemistry was utilized to gain insight into the possible interactions. These oxides were characterized by X-ray diffraction, SEM, FTIR, and AFM. Results revealed that green synthesis of MgO and Fe2O3 NPs was successful with abundant. MgO NPs were in vitro applied on osteoporosis patients (n = 35) and showed a significant elevation of vit D3 and Ca+2 (0.0001 > p < 0.001) levels, compared to healthy volunteers (n = 25). Thus, Hibiscus sabdariffa L. is a good candidate to prepare MgO NPs, with a promising enhancing effect on vit D3 and Ca+2 in osteoporosis. In addition, interactions of Fe2O3 and MgO NPs with ALP were determined by molecular docking study.

Associations between body composition, physical activity, and diet and radial bone microarchitecture in older adults: a 10-year population-based study

Bone strength is important to prevent osteoporotic fractures and determined by bone mass and microarchitecture. This study suggests that having higher lean mass and lower fat mass, avoiding western dietary patterns, and improving steps per day may all be important for maintaining bone mass and microarchitecture in aging.

PURPOSE

To describe associations between exposures of lean mass and fat mass, dietary patterns, serum 25-hydroxyvitamin D (25(OH)D), physical activity and grip strength, and bone outcome measures including bone mineral density and microarchitecture in older adults.

METHODS

Data on 201 older adults (mean age 72 years, female 46% at 10.7-year follow-up (phase 4) from a population-based cohort study collected at baseline and follow-up at 2.6 (phase 2), 5.1 (phase 3), and 10.7 years (phase 4) were analyzed. Exposures were lean and fat mass, dietary patterns, physical activity (steps per day), serum 25(OH)D concentrations, and grip strength during follow-ups. Bone measures at phase 4 including areal bone mineral density (aBMD) at the spine, hip, and whole body by dual-energy X-ray absorptiometry, and radial cortical and trabecular bone microarchitecture by high-resolution peripheral computed tomography (HRpQCT). The cumulative average values of exposures were calculated. Multivariable linear regression was used to analyze associations between exposures and bone measures.

RESULTS

Lean mass was beneficially associated with the hip, spine, and total body aBMD, radial cortical and trabecular bone area, and trabecular number and separation (β ranged from - 0.39/standard deviation (SD) to 0.73/SD). Fat mass was detrimentally associated with radial compact cortical and inner transitional zone bone area, vBMD, and porosity (β ranged from - 0.21 to 0.22/SD). Western dietary pattern scores were detrimentally associated with radial total and cortical bone vBMD and porosity (β ranged from - 0.20 to 0.20/SD). Steps per day were beneficially associated with inner transitional zone area and thickness (β = 0.12/SD and 0.19/SD), but no other measures. Grip strength and serum 25(OH)D were not associated with any radial bone measures.

CONCLUSIONS

Lean mass was beneficially associated with aBMD, radial bone area, and trabecular bone microarchitecture. Fat mass had detrimental associations with radial bone area, vBMD, and porosity. A western dietary pattern was detrimental for radial bone microarchitecture while more steps per day (but not grip strength or 25(OH)D) appeared beneficial.

In vivo and in vitro performances of chitosan-coated Mg-Zn-Zr-Gd-Ca alloys as bone biodegradable materials in rat models

Mg alloys have attracted significant attention as promising biomedical materials, specifically as fixation materials for promoting fracture healing. However, their unsatisfactory corrosion resistances hinder further clinical applications and thus require attention. This study aims to determine the performance of novel chitosan-coated Mg-1Zn-0.3Zr-2Gd-1Ca alloy and its ability to promote the healing of osteoporotic fractures. Moreover, its corrosion resistance and biocompatibility were assessed. Performance degradations of the samples were measured via electrochemical tests, weight loss test and morphological analysis, and the uncoated and chitosan-coated fixations were compared based on their effects on biocompatibility via the cytotoxicity test, X-rays, and hematoxylin and eosin staining. The effect of bone growth and healing was investigated via immunohistochemical test. Results of the electrochemical tests indicated that compared with the bare body, chitosan-coated Mg-Zn-Ca-Zr-Gd alloys improved by one order of magnitude. Additionally, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and weight loss test demonstrated that the corrosion resistance of the chitosan-coated Mg alloy is better than that of the uncoated alloy. In addition, cytotoxicity analysis indicated that the viability and morphology of the chitosan-coated alloy groups were superior to the uncoated groups in vitro. During in vivo analysis, chitosan-coated and uncoated Mg-1Zn-0.3Zr-2Gd-1Ca alloys were implanted into ovariectomized SD female rats with osteoporotic fractures for 1, 2, and 3 weeks. No displacement and shedding were observed through X-rays, and pathological analyses proved that the material was not harmful for liver and kidney tissues. Immunohistochemistry revealed that the chitosan-coated Mg-Zn-Ca-Zr-Gd alloy material contributed to the healing of osteoporotic fractures in the SD rat models. In conclusion, this study demonstrated the chitosan-coated Mg-Zn-Ca-Zr-Gd alloys have improved corrosion resistance and biocompatibility. Moreover, the alloy was found to accelerate the healing of osteoporotic fractures in SD rat models. Therefore, it has significant potential as a fixation material for osteoporotic fractures.

Role of estrone on the regulation of osteoblastogenesis

Although estradiol bone contribution has been deeply studied, little is known about the action of estrone. We investigated the direct action of estrone on osteoblasts growth and differentiation, with focus on the biochemical mechanism displayed by the estrogen. Murine calvarial osteoblast cultures in vitro exposed to 10 nM estrone were employed. Estrone enhanced gene expression of the osteogenic differentiation marker, Runx2 mRNA (150% above control). The hormone significantly increased cell proliferation (38% above control), nitric oxide production (108% above control), alkaline phosphatase activity (50% above control), in addition to stimulation of extracellular matrix mineralization. Using specific antagonists, we found that the mechanism of action of estrone involves estrogen receptor, nitric oxide synthase and MAPK signalling pathways participation. The hormone acts by its own and probably not via conversion to estradiol, since 17 B HSD inhibition did not affect the hormonal action. This work shows a novel action of estrone on bone cells promoting osteoblastogenesis.

Inhibitory effect of Astragalus polysaccharide on osteoporosis in ovariectomized rats by regulating FoxO3a /Wnt signaling pathway

Purpose:

To investigate inhibitory effect of Astragalus polysaccharide (APS) on osteoporosis in ovariectomized rats by regulating FoxO3a/Wnt2 signaling pathway.

Methods:

Postmenopausal osteoporosis (PMOP) animal model was developed by excising the bilateral ovaries of rats. The model rats were administered with APS (200 mg/kg, 400 mg/kg, 800 mg/kg) by intragastric administration once daily for 12 weeks. Bone density, bone metabolism index and oxidative stress index were measured in all groups. Furthermore, the regulation of APS of FoxO3a / Wnt2 signaling pathway was observed.

Results:

APS has an estrogen-like effect, which can increase bone mass, lower serum ALP and BGP values, increase blood calcium content, and increase bone density of the femur and vertebrae in rats. At the same time, APS can increase the bone mineral content of the femur, increase the maximum stress, maximum load and elastic modulus of the ovariectomized rats, improve oxidative stress in rats by increasing the gene expression of β-catenin and Wnt2 mRNA and inhibiting the gene expression of FoxO3a mRNA.

Conclusion:

Astragalus polysaccharide can effectively alleviate oxidative stress-mediated osteoporosis in ovariectomized rats, which may be related to its regulation of FoxO3a/Wnt2/β-catenin pathway.

Investigation and management of osteoporosis in aged trauma patients: a treatment algorithm adapted to the German guidelines for osteoporosis

BACKGROUND

Osteoporosis-associated fractures are of increasing importance in trauma surgery. Systematic diagnostics and treatment of osteoporosis during a hospital stay, however, remain inadequate. Therefore, a specific algorithm for diagnosing and treating osteoporosis in trauma surgery patients was developed based on the DVO (German Osteology Society) guideline for osteoporosis from 2014.

METHODS

In a first step, the individuals' age and risk profile for osteoporosis is identified considering specific fractures indicating osteoporosis and risk factors assessed by a specific questionnaire. In addition, physical activity, risk of falls, dietary habits and the individuals' medication are considered. Basic osteoporosis laboratory tests, a bone densitometry by dual-energy X-ray absorptiometry (DXA) and, if needed, X-rays of the spine are carried out to identify prevalent vertebral body fractures.

RESULTS

Based on the treatment algorithm adapted to the new guidelines for osteoporosis in the majority of proximal femoral fractures, treatment of osteoporosis could already be indicated without prior DXA. In case of preexisting glucocorticoid therapy, a history of previous fractures or other risk factors according to the risk questionnaire, the threshold of treatment has to be adjusted given the table of T-scores.

CONCLUSIONS

The treatment algorithm for diagnosing and treating osteoporosis in in-patient trauma surgery patients can help identify high-risk patients systematically and efficiently. As a result, osteoporosis-associated fractures or failure of osteosynthesis could be reduced, yet a prospective validation of the algorithm has to be completed.

[Prevalence and management of osteoporosis in trauma surgery. Implementation of national guidelines during inpatient fracture treatment]

BACKGROUND

Osteoporosis-associated fractures represent a risk factor for developing further fragility fractures. Therefore, guideline-oriented osteoporosis intervention is of utmost importance during inpatient fracture treatment.

PATIENTS AND METHODS

Women >50 years and men >60 years with fractures of the lumbar or thoracic spine, proximal femur, proximal humerus and distal radius were included in a prospective study. We analyzed the initiation of diagnosis and treatment of osteoporosis during the inpatient stay.

RESULTS

A total of 455 patients were included and bone mineral density measurement (DXA) was carried out in 65.9 %. Women underwent DXA in 69.5 % and men significantly less frequently in 52.1 %. Osteoporosis was diagnosed in 56.6 %, where women were affected in 56.2 % and men in 59 % of cases. In 83.8 % osteoporosis had been previously unknown. Treatment according to the guidelines of the Organisation of German Scientific Osteology-related Societies (DVO) was initiated in 86.7 % and 77.1 % of women >70 years and men >80 years required anti-resorptive treatment after DXA.

CONCLUSIONS

The majority of elderly patients with fractures also suffer from osteoporosis, independent of gender. Even nowadays, osteoporosis is predominantly not diagnosed until the incidence of a fracture. Therefore, the trauma surgeon is in a key position to initiate diagnosis and treatment of osteoporosis.

Pomegranate and its derivatives can improve bone health through decreased inflammation and oxidative stress in an animal model of postmenopausal osteoporosis

PURPOSE

Recently, nutritional and pharmaceutical benefits of pomegranate (PG) have raised a growing scientific interest. Since PG is endowed with anti-inflammatory and antioxidant activities, we hypothesized that it may have beneficial effects on osteoporosis.

METHODS

We used ovariectomized (OVX) mice as a well-described model of postmenopausal osteoporosis to study the influence of PG consumption on bone health. Mice were divided into five groups as following: two control groups sham-operated and ovariectomized (OVX CT) mice fed a standard diet, versus three treated groups OVX mice given a modified diet from the AIN-93G diet, containing 5.7% of PG lyophilized mashed totum (OVX PGt), or 9.6% of PG fresh juice (OVX PGj) or 2.9% of PG lyophilized mashed peel (OVX PGp).

RESULTS

As expected, ovariectomy was associated with a decreased femoral bone mineral density (BMD) and impaired bone micro-architecture parameters. Consumption of PGj, PGp, or PGt induced bone-sparing effects in those OVX mice, both on femoral BMD and bone micro-architecture parameters. In addition, PG (whatever the part) up-regulated osteoblast activity and decreased the expression of osteoclast markers, when compared to what was observed in OVX CT animals. Consistent with the data related to bone parameters, PG consumption elicited a lower expression of pro-inflammatory makers and of enzymes involved in ROS generation, whereas the expression of anti-inflammatory markers and anti-oxidant actors was enhanced.

CONCLUSION

These results indicate that all PG parts are effective in preventing the development of bone loss induced by ovariectomy in mice. Such an effect could be partially explained by an improved inflammatory and oxidative status.

External validation of the Garvan nomograms for predicting absolute fracture risk: the Tromsø study

Background

Absolute risk estimation is a preferred approach for assessing fracture risk and treatment decision making. This study aimed to evaluate and validate the predictive performance of the Garvan Fracture Risk Calculator in a Norwegian cohort.

Methods

The analysis included 1637 women and 1355 aged 60+ years from the Tromsø study. All incident fragility fractures between 2001 and 2009 were registered. The predicted probabilities of non-vertebral osteoporotic and hip fractures were determined using models with and without BMD. The discrimination and calibration of the models were assessed. Reclassification analysis was used to compare the models performance.

Results

The incidence of osteoporotic and hip fracture was 31.5 and 8.6 per 1000 population in women, respectively; in men the corresponding incidence was 12.2 and 5.1. The predicted 5-year and 10-year probability of fractures was consistently higher in the fracture group than the non-fracture group for all models. The 10-year predicted probabilities of hip fracture in those with fracture was 2.8 (women) to 3.1 times (men) higher than those without fracture. There was a close agreement between predicted and observed risk in both sexes and up to the fifth quintile. Among those in the highest quintile of risk, the models over-estimated the risk of fracture. Models with BMD performed better than models with body weight in correct classification of risk in individuals with and without fracture. The overall net decrease in reclassification of the model with weight compared to the model with BMD was 10.6% (p = 0.008) in women and 17.2% (p = 0.001) in men for osteoporotic fractures, and 13.3% (p = 0.07) in women and 17.5% (p = 0.09) in men for hip fracture.

Conclusions

The Garvan Fracture Risk Calculator is valid and clinically useful in identifying individuals at high risk of fracture. The models with BMD performed better than those with body weight in fracture risk prediction.

Impacts of body mass index, physical activity, and smoking on femoral bone loss: the Tromsø study

Bone mineral density (BMD) is a reflection of bone strength and lifestyles that preserve bone mass and may reduce fracture risk in old age. This study examined the effect of combined profiles of smoking, physical activity, and body mass index (BMI) on lifetime bone loss. Data were collected from the population-based Tromsø Study. BMD was measured as g/cm(2) by dual-energy X-ray absorptiometry (DXA) at the total hip and femoral neck in 2580 women and 2084 men aged 30 to 80 years in the 2001-02 survey, and repeated in 1401 women and 1113 men in the 2007-08 survey. Height and weight were measured and lifestyle information was collected through questionnaires. Data were analyzed using linear mixed models with second-degree fractional polynomials. From the peak at the age around 40 years to 80 years of age, loss rates varied between 4% at the total hip and 14% at femoral neck in nonsmoking, physically active men with a BMI of 30 kg/m(2) to approximately 30% at both femoral sites in heavy smoking, physically inactive men with a BMI value of 18 kg/m(2) . In women also, loss rates of more than 30% were estimated in the lifestyle groups with a BMI value of 18 kg/m(2) . BMI had the strongest effect on BMD, especially in the oldest age groups, but a BMI above 30 kg/m(2) did not exert any additional effect compared with the population average BMI of 27 kg/m(2) . At the age of 80 years, a lifestyle of moderate BMI to light overweight, smoking avoidance, and physical activity of 4 hours of vigorous activity per week through adult life may result in 1 to 2 standard deviations higher BMD levels compared with a lifestyle marked by heavy smoking, inactivity, and low weight. In the prevention of osteoporosis and fracture risk, the effect of combined lifestyles through adult life should be highlighted. © 2014 American Society for Bone and Mineral Research.

Rabbiteye blueberry prevents osteoporosis in ovariectomized rats

Objective

It has been forecasted that the rabbiteye blueberry could inhibit osteoporosis. However, the inhibition and prevention of osteoporosis via rabbiteye blueberry are still elusive. This study was aim to evaluate the anti-osteoporosis effects of rabbiteye blueberry in ovariectomized rats.

Methods

Thirty rats were randomly divided into three groups of ten rats each as follows: sham-operated group (SG), ovariectomized model control group (OMG), and ovariectomized rabbiteye blueberry treatment group (OBG). The blood mineral levels, the alkaline phosphatase (ALP) activity, and osteoprotegerin (OPG) level were determined. The expression analyses of type I collagen, integrin-β1, and focal adhesion kinase (FAK) were performed. Besides, the bone mineral density (BMD) and bone histomorphometry (BH) were measured.

Results

The ALP activity in SG and OBG was significantly lower than that in OMG. For the OPG level, the significant increase of OPG level in OBG was indicated compared with the other groups. The mRNA expression levels of type I collagen, integrin-β1, and FAK in OMG were significantly lower than those in other groups. The BMD in OMG were all significantly lower than those in SG and OBG. For BH, blueberry significantly improved the trabecular bone volume fraction, trabecular thickness, mean trabecular bone number, and bone formation rate, and decreased the trabecular separation, the percent of bone resorption perimeter, and mean osteoclast number in OBG compared with OMG.

Conclusions

The rabbiteye blueberries had an effective inhibition in bone resorption, bone loss, and reduction of bone strength of ovariectomized rats and could improve the BMD, osteogenic activity, and trabecular bone structure.

Progressively increasing fracture risk with advancing age after initial incident fragility fracture: the Tromsø study

The risk of subsequent fracture is increased after initial fractures; however, proper understanding of its magnitude is lacking. This population-based study examines the subsequent fracture risk in women and men by age and type of initial incident fracture. All incident nonvertebral fractures between 1994 and 2009 were registered in 27,158 participants in the Tromsø Study, Norway. The analysis included 3108 subjects with an initial incident fracture after the age of 49 years. Subsequent fracture (n = 664) risk was expressed as rate ratios (RR) and absolute proportions irrespective of death. The rates of both initial and subsequent fractures increased with age, the latter with the steepest curve. Compared with initial incident fracture rate of 30.8 per 1000 in women and 12.9 per 1000 in men, the overall age-adjusted RR of subsequent fracture was 1.3 (95% CI, 1.2-1.5) in women, and 2.0 (95% CI, 1.6-2.4) in men. Although the RRs decreased with age, the absolute proportions of those with initial fracture who suffered a subsequent fracture increased with age; from 9% to 30% in women and from 10% to 26% in men, between the age groups 50-59 to 80+ years. The type of subsequent fracture varied by age from mostly minor fractures in the youngest to hip or other major fractures in the oldest age groups, irrespective of type and severity of initial fracture. In women and men, 45% and 38% of the subsequent hip or other major fractures, respectively, were preceded by initial minor fractures. The risk of subsequent fracture is high in all age groups. At older age, severe subsequent fracture types follow both clinically severe and minor initial incident fractures. Any fragility fracture in the elderly reflects the need for specific osteoporosis management to reduce further fracture risk.

Maternal first-trimester diet and childhood bone mass: the Generation R Study

BACKGROUND

Maternal diet during pregnancy has been suggested to influence bone health in later life.

OBJECTIVE

We assessed the association of maternal first-trimester dietary intake during pregnancy with childhood bone mass.

DESIGN

In a prospective cohort study in 2819 mothers and their children, we measured first-trimester daily energy, protein, fat, carbohydrate, calcium, phosphorus, and magnesium intakes by using a food-frequency questionnaire and homocysteine, folate, and vitamin B-12 concentrations in venous blood. We measured childhood total body bone mass by using dual-energy X-ray absorptiometry at the median age of 6.0 y.

RESULTS

Higher first-trimester maternal protein, calcium, and phosphorus intakes and vitamin B-12 concentrations were associated with higher childhood bone mass, whereas carbohydrate intake and homocysteine concentrations were associated with lower childhood bone mass (all P-trend < 0.01). Maternal fat, magnesium intake, and folate concentrations were not associated with childhood bone mass. In the fully adjusted regression model that included all dietary factors significantly associated with childhood bone mass, maternal phosphorus intake and homocysteine concentrations most-strongly predicted childhood bone mineral content (BMC) [β = 2.8 (95% CI: 1.1, 4.5) and β = -1.8 (95% CI: -3.6, 0.1) g per SD increase, respectively], whereas maternal protein intake and vitamin B-12 concentrations most strongly predicted BMC adjusted for bone area [β = 2.1 (95% CI: 0.7, 3.5) and β = 1.8 (95% CI: 0.4, 3.2) g per SD increase, respectively].

CONCLUSION

Maternal first-trimester dietary factors are associated with childhood bone mass, suggesting that fetal nutritional exposures may permanently influence bone development.

Early healing of hydroxyapatite-coated implants in grafted bone of zoledronic acid-treated osteoporotic rabbits

BACKGROUND

Resorption of grafted bone and delayed osseointegration of implants are main problems associated with alveolar bone augmentation in dental implantology, especially for patients with osteoporosis. The aim of this study is to investigate the early healing response of implants to systemic treatment of zoledronic acid (ZA) in autogenous grafted iliac bone of osteoporotic rabbits.

METHODS

Ovariectomy (OVX) or sham operation was performed in 46 rabbits, and osteoporotic changes were verified in animals receiving OVX 3 months later. The remaining animals were divided into three groups (n = 12): sham, OVX, and OVX with ZA treatment (ZA group). Autogenous iliac bone grafting was performed in bilateral tibiae, and hydroxyapatite-coated titanium implants were simultaneously placed into the grafted bone. The animals were sacrificed 2 and 8 weeks later for examination.

RESULTS

At both time points, systemic treatment of ZA efficiently promoted bone healing of implants in grafted bone, and all histologic and microcomputed tomography bone indices, including mineralized bone volume, implant-bone contact ratio, connectivity density, trabecular thickness, and trabecular number, were significantly increased in the ZA group compared with the OVX-only group (P <0.01); implant-bone contact rates in the ZA group were even restored to levels similar to those of sham-operated animals (P >0.05). Furthermore, biomechanical testing demonstrated that removal torque of implants was significantly increased in the ZA group compared with the OVX group (P <0.01).

CONCLUSION

Systemic treatment with ZA could efficiently promote early bone healing of implants in autogenous grafted bone of osteoporotic rabbits by increasing early osseointegration and fixation of implants.

Two-year cost comparison of vertebroplasty and kyphoplasty for the treatment of vertebral compression fractures: are initial surgical costs misleading?

The costs for treating kypho- and vertebroplasty patients were evaluated at up to 2 years postsurgery. There were no significant differences in adjusted costs in the first 9 months postsurgery, but kyphoplasty patients were associated with significantly lower adjusted treatment costs by 6.8-7.9% in the remaining periods through 2 years postsurgery.

INTRODUCTION

Vertebral augmentation has been shown to be safe and effective for treating vertebral compression fractures. Comparative cost studies of initial treatment costs for kypho- and vertebroplasty have been mixed. The purpose of our study was to compare the costs for treating kypho- and vertebroplasty patients at up to 2 years postsurgery.

METHODS

Vertebroplasty and kyphoplasty patients diagnosed with pathologic or closed lumbar/thoracic vertebral fractures were identified from the 5% sample of the Medicare dataset (2006-2009). The final study cohort with at least 2 years follow-up comprised of 1,609 vertebroplasty and 2,878 kyphoplasty patients. The cumulative treatment costs (adjusted to June 2011 US$) were determined from the payer perspective. Differences in costs and length of stay were assessed by generalized linear mixed model regression, adjusting for covariates.

RESULTS

The average adjusted costs for vertebroplasty patients within the first quarter and the first 2 years postsurgery were $14,585 [95% confidence interval (CI), $14,109-15,078] and $44,496 (95% CI, $42,763-46,299), respectively. The corresponding average adjusted costs for kyphoplasty patients were $15,117 (95% CI, $14,752-15,491) and $41,339 (95% CI, $40,154-42,560). There were no significant differences in adjusted costs in the first 9 months postsurgery, but kyphoplasty patients were associated with significantly lower adjusted treatment costs by 6.8-7.9% in the remaining periods through 2 years postsurgery.

CONCLUSION

Our present study addresses some of the limitations in previous comparative cost studies of vertebroplasty and kyphoplasty. The higher adjusted costs for vertebroplasty patients than kyphoplasty patients by 1 year following the surgery reflect greater utilization of medical resources.

Life expectancy following diagnosis of a vertebral compression fracture

SUMMARY

The life expectancy of vertebral compression fracture (VCF) patients was evaluated as a function of their treatment. Compared to non-operated patients, the kyphoplasty and vertebroplasty patient cohort had 115% and 44% greater adjusted life expectancy, respectively. Kyphoplasty patients had a 34% greater adjusted life expectancy than vertebroplasty patients.

INTRODUCTION

Balloon kyphoplasty and vertebroplasty are minimally invasive procedures for the treatment of painful VCFs. This comparative effectiveness study characterized the life expectancy of VCF patients as a function of their treatment.

METHODS

Life expectancy of VCF patients in the 100% U.S. Medicare dataset (2005-2008) was estimated using a parametric Weibull survival model (adjusted for comorbidities), and compared between operated and non-operated patients as well as between kyphoplasty and vertebroplasty patients. A total of 858,978 patients with a newly diagnosed VCF were identified, including 119,253 kyphoplasty patients (13.9%) and 63,693 vertebroplasty patients (7.4%).

RESULTS

Adjusted life expectancy was 85% greater for operated than non-operated patients (p < 0.001; 95% confidence interval: 82-89%). Compared to non-operated patients, the kyphoplasty and vertebroplasty patient cohort had 115% (p < 0.001; 95% confidence interval: 111-119%) and 44% (p < 0.001; 95% confidence interval: 42-47%) greater adjusted life expectancy, respectively. Kyphoplasty patients had a 34% greater adjusted life expectancy than vertebroplasty patients (p < 0.001; 95% confidence interval: 31-36%). Across all gender-age groups, the median life expectancy predicted by the parametric Weibull model was 2.2-7.3 years greater for operated than non-operated patients.

CONCLUSIONS

Statistically significant and substantial differences in life expectancy were observed between the treated and non-treated cohorts in the Medicare population. Among the treated cohorts, patients in the vertebroplasty group experienced less of a survival benefit than those who received kyphoplasty. The results will be a useful basis for future cost effectiveness studies of VCF treatments for the Medicare population.

The importance of a thorough medical and pharmacological history before dental implant placement

The risk of osteonecrosis in patients treated with bisphosphonates is well known and guidelines intended to prevent this complication have been established and accepted. Bisphosphonate related osteonecrosis of the jaws (BRONJ) is a unique condition in which even past administration of medication may be of current and future relevance. We present a case of BRONJ in the maxilla after dental implant placement. The patient suffered from osteoporosis and had been treated with oral alendronate sodium in the past. However, the medication was stopped two years before implant placement, and the treating dentist was unaware of the patient's past bisphosphonate use. Prevention of BRONJ is based on identifying at-risk patients, and then avoiding or modifying dentoalveolar surgical procedures in these individuals. Nevertheless, there seems to be some difficulties identifying patients at risk. We present some of the challenges that impede thorough assessment of a patient's medical background (review of systems) in the dental office, and suggest possible solutions.

Cost-effectiveness analysis of treatments for vertebral compression fractures

BACKGROUND

Vertebral compression fractures (VCFs) can be treated by nonsurgical management or by minimally invasive surgical treatment including vertebroplasty and balloon kyphoplasty.

OBJECTIVE

The purpose of the present study was to characterize the cost to Medicare for treating VCF-diagnosed patients by nonsurgical management, vertebroplasty, or kyphoplasty. We hypothesized that surgical treatments for VCFs using vertebroplasty or kyphoplasty would be a cost-effective alternative to nonsurgical management for the Medicare patient population.

METHODS

Cost per life-year gained for VCF patients in the US Medicare population was compared between operated (kyphoplasty and vertebroplasty) and non-operated patients and between kyphoplasty and vertebroplasty patients, all as a function of patient age and gender. Life expectancy was estimated using a parametric Weibull survival model (adjusted for comorbidities) for 858 978 VCF patients in the 100% Medicare dataset (2005-2008). Median payer costs were identified for each treatment group for up to 3 years following VCF diagnosis, based on 67 018 VCF patients in the 5% Medicare dataset (2005-2008). A discount rate of 3% was used for the base case in the cost-effectiveness analysis, with 0% and 5% discount rates used in sensitivity analyses.

RESULTS

After accounting for the differences in median costs and using a discount rate of 3%, the cost per life-year gained for kyphoplasty and vertebroplasty patients ranged from $US1863 to $US6687 and from $US2452 to $US13 543, respectively, compared with non-operated patients. The cost per life-year gained for kyphoplasty compared with vertebroplasty ranged from -$US4878 (cost saving) to $US2763.

CONCLUSIONS

Among patients for whom surgical treatment was indicated, kyphoplasty was found to be cost effective, and perhaps even cost saving, compared with vertebroplasty. Even for the oldest patients (85 years of age and older), both interventions would be considered cost effective in terms of cost per life-year gained.

The clinical use of denosumab for the management of low bone mineral density in postmenopausal women

Osteoporosis is a leading cause of debility and declining quality of life in postmenopausal women worldwide. Treatment of osteoporosis has been ubiquitous throughout the developed world since the mid-1990s, most notably with the introduction of bisphosphonates in 1995. Nonetheless, the incidence of hip fractures increased by 25% between 1990 and 2000, despite advances in osteoporosis therapy. Studies indicate that bone density increases over the first 3 years of bisphosphonate therapy and then plateaus or perhaps even declines, placing these patients at greater risk of fracture. Since hip fractures are associated with increased morbidity, mortality, and increased cost of health care, improvements in treating osteoporosis are critical. Denosumab is a novel monoclonal antibody targeted against the receptor activator of nuclear factor-κB ligand (RANKL) that inhibits osteoclast activity. Initial data suggest that denosumab increases bone mineral density for greater than 3 years. Of greater importance, denosumab has been shown to decrease vertebral fractures by 68%, nonvertebral fractures by 19%, and hip fractures by 42% for at least 36 months. Data also indicate that the safety profile of denosumab is equivalent to other drugs used in osteoporosis management, but potential risks of immunosuppression and cancer have been hypothesized.

Vertebral fracture assessment by new dual-energy X-ray absorptiometry

The aim of this study was to investigate the diagnostic performance of new dual-energy X-ray absorptiometry (DXA) technologies in the detection of vertebral fractures (VFs). Sixty-eight patients were submitted to DXA and conventional radiography (XR) on the same day. Lateral images of the spine were independently evaluated by three radiologists with different experience in skeletal imaging, in two sessions with 7 days between evaluations of the same anonymous images. The most expert physician repeated the analysis in a subsequent reading session after further 7 days. Results from expert XR evaluation were considered as gold standard. A semiquantitative approach was used to interpret images and morphometric analysis was performed when a VF was suspected. Seventy vertebrae (70/884, 7.9%) were excluded from the lesion-based analysis, as not evaluable: 11/70 (15.7%) missed by XR only, 56/70 (80.0%) missed by DXA only, 3/70 (4.3%) missed by both techniques (upper thoracic spine). Forty "true" fractures were detected (4.9% out of 814 vertebrae) in 26 patients (38.2% of the 68 studied patients). Twenty-five (62.5%) were mild fractures. DXA sensitivity and specificity were 70.0% and 98.3% on a lesion-based analysis, 73.1% and 90.5% on a patient-based analysis. Intra-observer agreement was excellent with no significant difference between the two techniques. Inter-observer agreement among the 3 observers was higher for XR (k=0.824 versus 0.720 in the detection of VFs, p=0.011). DXA accuracy was not influenced by radiologist experience; T4-L4 assessability as well as reproducibility and repeatability of the two techniques and accuracy of DXA were independent from sex, age, body mass index, grade of arthrosis. However DXA sensitivity was affected by mild VFs. Vertebral level did not affect the diagnostic performance with exception of vertebral body assessability. Latest improvements make VFs assessment by DXA competitive with traditional radiographic gold standard, providing consistent advantages and attractions. Few limitations still affect DXA performance and need to be overcome.

Borage and fish oils lifelong supplementation decreases inflammation and improves bone health in a murine model of senile osteoporosis

Fats are prevalent in western diets; they have known deleterious effects on muscle insulin resistance and may contribute to bone loss. However, relationships between fatty acids and locomotor system dysfunctions in elderly population remain controversial. The aim of this study was to analyze the impact of fatty acid quality on the age related evolution of the locomotor system and to understand which aging mechanisms are involved. In order to analyze age related complications, the SAMP8 mouse strain was chosen as a progeria model as compared to the SAMR1 control strain. Then, two months old mice were divided in different groups and subjected to the following diets : (1) standard "growth" diet - (2) "sunflower" diet (high ω6/ω3 ratio) - (3) "borage" diet (high γ-linolenic acid) - (4) "fish" diet (high in long chain ω3). Mice were fed ad libitum through the whole protocol. At 12 months old, the mice were sacrificed and tissues were harvested for bone studies, fat and muscle mass measures, inflammation parameters and bone cell marker expression. We demonstrated for the first time that borage and fish diets restored inflammation and bone parameters using an original model of senile osteoporosis that mimics clinical features of aging in humans. Therefore, our study strongly encourages nutritional approaches as relevant and promising strategies for preventing aged-related locomotor dysfunctions.

Transient muscle paralysis degrades bone via rapid osteoclastogenesis

A unilateral injection of botulinum toxin A (BTxA) in the calf induces paralysis and profound loss of ipsalateral trabecular bone within days. However, the cellular mechanism underlying acute muscle paralysis-induced bone loss (MPIBL) is poorly understood. We hypothesized that MPIBL arises via rapid and extensive osteoclastogenesis. We performed a series of in vivo experiments to explore this thesis. First, we observed elevated levels of the proosteoclastogenic cytokine receptor activator for nuclear factor-κB ligand (RANKL) within the proximal tibia metaphysis at 7 d after muscle paralysis (+113%, P<0.02). Accordingly, osteoclast numbers were increased 122% compared with the contralateral limb at 5 d after paralysis (P=0.04) and MPIBL was completely blocked by treatment with human recombinant osteoprotegerin (hrOPG). Further, conditional deletion of nuclear factor of activated T-cells c1 (NFATc1), the master regulator of osteoclastogenesis, completely inhibited trabecular bone loss (-2.2±11.9%, P<0.01). All experiments included negative control assessments of contralateral limbs and/or within-animal pre- and postintervention imaging. In summary, transient muscle paralysis induced acute RANKL-mediated osteoclastogenesis resulting in profound local bone resorption. Elucidation of the pathways that initiate osteoclastogenesis after paralysis may identify novel targets to inhibit bone loss and prevent fractures.

Cell attachment and response to photocured, degradable bone adhesives containing tricalcium phosphate and purmorphamine

The aim of this study was to quantify and provide evidence as to how addition of tricalcium phosphate (β-TCP) and the Hedgehog agonist purmorphamine to a degradable bone adhesive affects cell attachment/proliferation and Hedgehog pathway activation. Fourier transform infrared spectroscopy demonstrated that high levels (75 wt.%) of β-TCP addition reduced the photocure rate of the chosen poly(propylene glycol-co-lactide) dimethacrylate (PPLM) bone adhesive, but this problem was overcome by increased light exposure. In phosphate-buffered saline the total surface mass loss of set 15 mm diameter PPLM films was ∼3.2 mg in 12 weeks, irrespective of thickness (200 or 400 μm) or β-TCP level (50 or 75 wt.%). With 400 μm samples there was additional bulk material loss. Proliferation of pre-osteoblast cells (MC3T3-E1) on the set adhesive surfaces was enhanced by decreased sample thickness or filler content increase. Degradation evidence suggested that both effects were due to reduced acidic polymeric degradation products. Activation of the Hedgehog pathway was quantified by measuring Gli expression in Light II reporter cells. The 0.01 and 0.1 wt.% purmorphamine in composite discs (400 μm, 75 wt.% β-TCP) enhanced Gli expression of attached cells 2- and 5-fold, respectively, without influencing their number. Pre-storage of the composite samples in culture medium had no detrimental effect on this response. Furthermore, sample storage medium gave no enhanced Gli expression in cells on tissue culture plastic. This suggests drug release levels were very low. Purmorphamine and β-TCP incorporation in PPLM adhesives might, therefore, provide prolonged enhancement of in vivo bone repair without systemic drug side-effects.