Use of a performance algorithm improves utilization of vertebral fracture assessment in clinical practice

Differential risk of fracture attributable to type 2 diabetes mellitus according to skeletal site

BACKGROUND

Impaired bone quality, especially related to accumulation of advanced glycation end-products (AGEs) and higher incidence of falls contribute substantially to a higher risk of fracture associated with type 2 diabetes mellitus (T2DM). These factors may predispose to fractures more at skeletal sites where impaired bone toughness and falls play a larger pathogenic role (such as hip fractures) compared to skeletal sites where they are less important (such as vertebral fractures).

OBJECTIVE

To determine if the associations of T2DM with prevalent and incident vertebral fractures are as strong as they are for hip and other non-vertebral fractures.

METHODS

Amongst 80,238 individuals in the Manitoba Bone Density Program database (mean [SD] age 64.4 [11.1] years, 89.8% female, 8676 with diagnosed T2DM) with a baseline BMD test (1996-2016), we estimated hazard ratios (HRs) for incident clinical fracture at different skeletal sites in those with compared to those without T2DM using Cox proportional hazards models over a mean (SD) 9.0 (5.0) year follow-up period. We also estimated odds ratios for prevalent vertebral fracture on VFA images amongst 9594 individuals (mean [SD] 76 [6.8] years, 1185 with T2DM diagnosis at time of DXA-VFA) and for prior clinical fractures at different skeletal sites using logistic regression models.

RESULTS

After multivariable adjustment, T2DM was associated with incident hip (HR 1.63, 95% CI 1.44 to 1.85) and proximal humerus fractures (HR 1.59, 95% CI 1.39 to 1.83), but was not associated with incident forearm fracture (HR 1.00, 95% CI 0.86 to 1.17) and only weakly with incident clinical vertebral fracture (HR 1.16, 95% CI 1.01 to 1.33). Similarly, T2DM was associated with prior hip (OR 1.78, 95% CI 1.21 to 2.61) and prior proximal humerus fracture (OR 1.31, 95% CI 1.02 to 1.68) but not with prior forearm (OR 0.89, 95% CI 0.74 to 1.06) or prevalent vertebral fracture on VFA images (OR 0.91, 95% CI 0.77 to 1.08).

CONCLUSION

T2DM is a stronger risk factor for hip and proximal humerus fractures than for vertebral and wrist fractures. Further research is warranted to determine if the known differences in falls and/or bone quality between T2DM and age-related osteoporosis account for these differential associations.

Associations of clinically recognized vs unrecognized vertebral fracture with mortality

PURPOSE

Our purpose was to contrast mortality associated with clinically undiagnosed prevalent vertebral fracture recognized on densitometric vertebral fracture assessment (VFA) and prior clinically diagnosed vertebral fracture.

METHODS

Between 2010 and 2016, 9679 men and women (mean age [SD] 76 [6.9] years, 93% women) with central site bone density T-score ≤ -1.5 had VFA images obtained at the time of bone densitometry. Vertebrae between T4 and L4 inclusive were evaluated for prevalent vertebral fracture on these images. Participants were categorized into three mutually exclusive groups; those with no vertebral fracture on VFA and no prior clinically diagnosed vertebral fracture (n = 7983), those with a definite vertebral fracture on VFA but no vertebral fracture clinically diagnosed before the index VFA date (n = 1376), and those with a prior clinically diagnosed vertebral fracture (n = 320). We ascertained mortality after the index VFA date using Manitoba provincial vital statistics files over a mean 2.8 (SD 1.7) years. We used Cox proportional hazards models to estimate the hazard ratios (HR) and 95% confidence intervals (C.I.) of prevalent vertebral fractures with mortality adjusted for multiple covariates.

RESULTS

Adjusted for age and sex, those with clinically undiagnosed vertebral fracture on VFA had an HR of 1.22 (95% C.I. 1.00 to 1.50) for mortality, and those with a prior clinically diagnosed vertebral fracture had an HR of 1.78 (95% C.I. 1.27 to 2.50) for mortality compared to those with no prevalent vertebral fracture. After further adjustment for comorbidity score, current smoking, and other causes of mortality, these associations were slightly attenuated (HRs 1.18 [95% C.I. 0.95 to 1.45] and of 1.70 [95% C.I. 1.21 to 2.40], respectively). Stratified by elapsed years since diagnosis, clinical vertebral fractures were associated with excess mortality for up to 10 years after their occurrence.

CONCLUSION

Clinically undiagnosed prevalent vertebral fracture detected on densitometric VFA images are weakly associated with subsequent mortality adjusted for age and sex, but not after accounting for other causes of mortality. Clinical vertebral fractures are associated with increased mortality for ten years after their diagnosis, even after accounting for other causes of mortality.

A Risk Assessment Tool for Predicting Fragility Fractures and Mortality in the Elderly

Existing fracture risk assessment tools are not designed to predict fracture-associated consequences, possibly contributing to the current undermanagement of fragility fractures worldwide. We aimed to develop a risk assessment tool for predicting the conceptual risk of fragility fractures and its consequences. The study involved 8965 people aged ≥60 years from the Dubbo Osteoporosis Epidemiology Study and the Canadian Multicentre Osteoporosis Study. Incident fracture was identified from X-ray reports and questionnaires, and death was ascertained though contact with a family member or obituary review. We used a multistate model to quantify the effects of the predictors on the transition risks to an initial and subsequent incident fracture and mortality, accounting for their complex interrelationships, confounding effects, and death as a competing risk. There were 2364 initial fractures, 755 subsequent fractures, and 3300 deaths during a median follow-up of 13 years (interquartile range [IQR] 7-15). The prediction model included sex, age, bone mineral density, history of falls within 12 previous months, prior fracture after the age of 50 years, cardiovascular diseases, diabetes mellitus, chronic pulmonary diseases, hypertension, and cancer. The model accurately predicted fragility fractures up to 11 years of follow-up and post-fracture mortality up to 9 years, ranging from 7 years after hip fractures to 15 years after non-hip fractures. For example, a 70-year-old woman with a T-score of -1.5 and without other risk factors would have 10% chance of sustaining a fracture and an 8% risk of dying in 5 years. However, after an initial fracture, her risk of sustaining another fracture or dying doubles to 33%, ranging from 26% after a distal to 42% post hip fracture. A robust statistical technique was used to develop a prediction model for individualization of progression to fracture and its consequences, facilitating informed decision making about risk and thus treatment for individuals with different risk profiles. © 2020 American Society for Bone and Mineral Research.

Vertebral Fracture Assessment Increases Use of Pharmacologic Therapy for Fracture Prevention in Clinical Practice

The impact of vertebral fracture assessment (VFA) on lateral spine images in clinical practice on subsequent patient use of fracture prevention medication is unknown. Our objective was to determine the association of prevalent vertebral fracture identified on bone density lateral spine images (positive VFA) with subsequent use of fracture prevention therapy in usual clinical practice, using the Manitoba Bone Density Program database prospective observational cohort. Since 2010, targeted VFA imaging has been done at the time of bone densitometry in Manitoba for 21% of women and men meeting criteria based on age, bone mineral density (BMD), height loss, and glucocorticoid use. Among 6652 treatment-naive individuals with at least 90 days follow-up who had VFA imaging, 923 (13.9%) had one or more definite vertebral fractures identified using a modified algorithm-based qualitative (ABQ) method. For those with a positive VFA, their bone density reports stated the patient was at high risk of subsequent fracture and qualified for fracture prevention therapy. Subsequent osteoporosis treatment initiated within the next 12 months was identified using population-based pharmacy data. Logistic regression models were used to estimate the association of positive VFA with subsequent prescription (Rx), compared to negative VFA. Fracture prevention medication was started by 2127 (32%) individuals, 52.3% with positive versus 28.4% with negative VFA (p value <0.001). This association was substantially stronger in those designated (before VFA results were known) to have low or moderate fracture risk compared to high fracture risk (interaction p value <0.001), and in those with osteopenia (OR 4.51; 95% CI, 3.48 to 5.85) compared to those with osteoporosis by BMD criteria (OR 1.72; 95% CI, 1.43 to 2.08, interaction p value <0.001). Targeted VFA imaging at the time of bone densitometry substantially improves identification of those at high fracture risk and fracture prevention medication use among those with prevalent vertebral fracture. © 2019 American Society for Bone and Mineral Research. © 2019 American Society for Bone and Mineral Research.

Prevalent vertebral fracture on bone density lateral spine (VFA) images in routine clinical practice predict incident fractures

PURPOSE

The predictive validity of vertebral fracture assessment (VFA) on bone density lateral spine images to identify prevalent vertebral fractures in routine clinical practice has not been established. Our objective was to estimate the associations of prevalent vertebral fracture identified on VFA images in routine practice with incident hip, all non-vertebral, major osteoporotic, and clinical vertebral fractures, using the Manitoba Bone Density database.

METHODS

From 2010 onward, 9972 men and women (mean age [SD] 76 [6.9] years) had VFA images obtained at the time of bone densitometry that were interpreted for vertebral fracture by the clinicians reading the bone density tests. Definite and possible prevalent vertebral fractures, respectively, were identified in 1575 (15.8%) and 293 (2.9%) using a modified Algorithm Based Qualitative method. We ascertained incident fractures using Manitoba provincial health databases over a mean 2.8 (SD 1.7) years and used Cox proportional hazards models to estimate the associations of prevalent vertebral fractures with incident fractures.

RESULTS

Compared to no prevalent vertebral fracture, those with definite prevalent vertebral fracture had higher hazard ratios for incident hip (HR 1.95, 95% C.I. 1.45 to 2.62), non-vertebral (HR 1.99, 95% C.I. 1.68 to 2.35), and clinical vertebral fracture (HR 2.68, 95% C.I. 1.69 to 4.23) adjusted for age, bone mineral density, body mass index, prior fracture, parental hip fracture, glucocorticoid use, alcohol use, smoking, and rheumatoid arthritis. These associations did not vary by FRAX fracture risk estimates or bone mineral density category.

CONCLUSION

Prevalent vertebral fractures identified on densitometric VFA images in routine clinical practice are strongly associated with incident fractures, and this study is the first to show this using any lateral spine imaging modality outside of research settings. These findings are strong evidence supporting the targeted use of densitometric VFA imaging among post-menopausal women and older men referred for bone densitometry.

Glucocorticoid-Induced Osteoporosis: Management Challenges in Older Patients

Glucocorticoid-induced osteoporosis remains the most common type of secondary osteoporosis, mostly due to use of oral glucocorticoids rather than due to endogenous overproduction of cortisol. Partly because glucocorticoids are prescribed by a wide variety of clinicians for many different inflammatory disorders, only a minority of older individuals have adequate and timely assessment of their enhanced fracture risk, and fewer are offered treatment. Assessment should include bone density, the FRAX calculation, and, in many cases, images of the spine. Glucocorticoids decrease osteoblast function and increase apoptosis of osteoblasts and osteocytes, leading to increased fracture risk soon after starting glucocorticoids. Guidelines provide evidence-based recommendations for evaluation and treatment, but there are differences in extant guidelines, and methods to improve adherence to the guidelines have mostly failed. A strong case can be made to use anabolic drugs first in high-risk patients based on pathophysiology and head-to-head clinical trials.

Vertebral Fracture Identification as Part of a Comprehensive Risk Assessment in Patients with Osteoporosis

PURPOSE OF REVIEW

To review current evidence regarding the vertebral fracture prevalence, the accuracy of vertebral fracture identification on current imaging technologies, and the potential impact of vertebral fracture identification on fracture risk.

RECENT FINDINGS

Important new studies have clarified the features of prevalent vertebral fracture that most strongly predict incident fractures. Age- and sex-stratified estimates of vertebral fracture prevalence on densitometric lateral spine images in the US population are now available. The accuracy of densitometric vertebral fracture assessment, how computed tomography scans and other spinal images obtained for indications other than vertebral fracture assessment can be leveraged to detect prevalent vertebral fractures, and the potential impact of vertebral fracture assessment on patient and provider fracture risk management behavior have been clarified. Substantial progress has been made regarding screening strategies using lateral spine imaging to detect prevalent vertebral fracture in the older population. Further research regarding implementation of these strategies in clinical practice and their impact on clinical outcomes is needed.

ADDING VFA TO DXA IDENTIFIES FRACTURE RISK IN A WAY NOT DUPLICATED BY OTHER MEASURES

OBJECTIVE

Published studies have demonstrated that adding vertebral fracture assessment (VFA) to dual-energy X-ray absorptiometry (DXA) identifies more patients with increased fracture risk than DXA alone. But who needs VFA? This study attempts to determine if some test other than VFA could duplicate the additional information obtained by performing VFA on all first-time patients. This study looked at the Fracture Risk Assessment Tool (FRAX), height loss, age, documented back pain, and nonvertebral fragility fractures.

METHODS

VFA was performed on 1,259 (all) DXA patients at their first visit from March 2010 through September 2013. All DXA and VFA results were read by the same International Society for Clinical Densitometry-certified clinician.

RESULTS

By DXA alone, 44% were osteoporosis. Adding VFA increased clinical osteoporosis by 36% of the original total patients. Eighty-three "normal bone mineral density" patients were changed to clinical osteoporosis. FRAX identified 53% of the patients with diagnosis changes. Historical height loss was not reliable. Increasing age correlated only weakly with clinical osteoporosis.

CONCLUSION

These are modest numbers from a nonacademic referral practice and may not be typical of other populations. Thirty-six percent of our patients were misclassified by DXA alone, with fragility fractures already taken into account for T-scores of -1.5 and lower. FRAX, height loss, age, back pain, and fragility fractures all failed to identify many of the patients identified by VFA. Seeing the lateral spine images obtained by VFA influenced patients and families. VFA on all first-time patients should be reconsidered.

ABBREVIATIONS

BMD = bone mineral density DXA = dual-energy X-ray absorptiometry FRAX = Fracture Risk Assessment Tool HL = height loss ISCD = International Society for Clinical Densitometry VF = vertebral fracture VFA = vertebral fracture assessment.

Spinal radiographs in those with back pain-when are they appropriate to diagnose vertebral fractures?

The presence of an osteoporotic vertebral fracture improves fracture risk assessment and may change management, so it is vital for healthcare professionals to assess patients for the presence or absence of these fractures. This may be particularly important in the presence of back pain. However, the correlation between low back symptoms and spinal imaging results is poor and the pathophysiology of most low back pain is not known, leading to a common conclusion that spinal radiographs are not appropriate for the assessment of back pain. For individual patients with back pain, spinal radiographs should be considered if they have certain features in the history and examination. As well as the traditional risk factors for osteoporosis, self-reported descriptives of back pain and novel physical examination findings have been shown to make the presence of vertebral fractures more likely. Systematic approaches have the potential to improve bone health across the population but need to be targeted to be cost-effective. Spinal radiographs should be considered for individual older patients with back pain if they have certain additional features in the history and examination.

The Clinical Utility of Vertebral Fracture Assessment in Predicting Fractures

Vertebral fracture (VF) is the most common type of osteoporotic fracture. VFs are associated with diminished quality of life and high morbidity and mortality. The presence of a VF, especially a recent one, is an important risk factor for developing another fracture. However, most VFs are not clinically recognized. VF assessment by dual-energy X-ray absorptiometry is a convenient, low-cost, low-radiation, reliable method to identify VFs during bone mineral density measurement. The finding of a previously unrecognized VF may change the diagnostic classification, assessment of fracture risk, and treatment strategies. This paper focuses on the utility of VF assessment in clinical practice.

Prediction of Incident Major Osteoporotic and Hip Fractures by Trabecular Bone Score (TBS) and Prevalent Radiographic Vertebral Fracture in Older Men

Trabecular bone score (TBS) has been shown to predict major osteoporotic (clinical vertebral, hip, humerus, and wrist) and hip fractures in postmenopausal women and older men, but the association of TBS with these incident fractures in men independent of prevalent radiographic vertebral fracture is unknown. TBS was estimated on anteroposterior (AP) spine dual-energy X-ray absorptiometry (DXA) scans obtained at the baseline visit for 5979 men aged ≥65 years enrolled in the Osteoporotic Fractures in Men (MrOS) Study and its association with incident major osteoporotic and hip fractures estimated with proportional hazards models. Model discrimination was tested with Harrell's C-statistic and with a categorical net reclassification improvement index, using 10-year risk cutpoints of 20% for major osteoporotic and 3% for hip fractures. For each standard deviation decrease in TBS, there were hazard ratios of 1.27 (95% confidence interval [CI] 1.17 to 1.39) for major osteoporotic fracture, and 1.20 (95% CI 1.05 to 1.39) for hip fracture, adjusted for FRAX with bone mineral density (BMD) 10-year fracture risks and prevalent radiographic vertebral fracture. In the same model, those with prevalent radiographic vertebral fracture compared with those without prevalent radiographic vertebral fracture had hazard ratios of 1.92 (95% CI 1.49 to 2.48) for major osteoporotic fracture and 1.86 (95% CI 1.26 to 2.74) for hip fracture. There were improvements of 3.3%, 5.2%, and 6.2%, respectively, of classification of major osteoporotic fracture cases when TBS, prevalent radiographic vertebral fracture status, or both were added to FRAX with BMD and age, with minimal loss of correct classification of non-cases. Neither TBS nor prevalent radiographic vertebral fracture improved discrimination of hip fracture cases or non-cases. In conclusion, TBS and prevalent radiographic vertebral fracture are associated with incident major osteoporotic fractures in older men independent of each other and FRAX 10-year fracture risks, and these data support their use in conjunction with FRAX for fracture risk assessment in older men.

Vertebral Fractures: Clinical Importance and Management

Vertebral fractures are common and can result in acute and chronic pain, decreases in quality of life, and diminished lifespan. The identification of vertebral fractures is important because they are robust predictors of future fractures. The majority of vertebral fractures do not come to clinical attention. Numerous modalities exist for visualizing suspected vertebral fracture. Although differing definitions of vertebral fracture may present challenges in comparing data between different investigations, at least 1 in 5 men and women aged >50 years have one or more vertebral fractures. There is clinical guidance to target spine imaging to individuals with a high probability of vertebral fracture. Radiology reports of vertebral fracture need to clearly state that the patient has a "fracture," with further pertinent details such as the number, recency, and severity of vertebral fracture, each of which is associated with risk of future fractures. Patients with vertebral fracture should be considered for antifracture therapy. Physical and pharmacologic modalities of pain control and exercises or physiotherapy to maintain spinal movement and strength are important components in the care of vertebral fracture patients.

Vertebral fracture assessment: Current research status and application in patients with kyphoplasty

Imaging of the spine is of paramount importance for the recognition of osteoporotic vertebral fractures (VFs), and standard radiography (SR) of the spine is the suggested diagnostic method but is not routinely used because of the cost and radiation exposure considerations. VF assessment (VFA) is an efficient, low radiation method for identifying VFs at the time of bone mineral density (BMD) measurement. Prediction models used to indicate the need for VFA may have little predictive power in subspecialty referral populations such as rheumatologic patients or patients who underwent kyphoplasty. Rheumatologic patients are frequently at increased risk for VFs, and VFA should be performed on an individual basis, also taking in account the guidelines for the general population. Kyphoplasty is a new minimal invasive procedure for the treatment of VFs and is being performed with increasing frequency. Following kyphoplasty, there may be a risk of new VFs in adjacent vertebrae. The assessment and follow-up of patients who underwent kyphoplasty requires repetitive X-ray imaging with the known limitations of SR. Thus, VFA may facilitate the evaluation of VFs in these patients because most of the kyphoplasty patients would fulfill the criteria. In a pilot study, we measured the BMD and performed VFA in 28 patients treated with kyphoplasty. Ratios of anterior to posterior (A/P) and middle to posterior (M/P) height were measured, and Genant’s method was used to classify vertebrae accordingly. Intraobserver and interobserver reliability for A/P, M/P and the Genant’s method were determined. Only 1 patient did not meet the criteria for VFA. Of the 364 available vertebrae, 295 could be analyzed. Most missing data (concerning 69 vertebrae) occurred in the upper thoracic region. Three of the 69 non-eligible vertebrae were lumbar vertebrae with cement leakage from the kyphoplasty procedure. In our hands, VFA was highly reproducible, demonstrating very good agreement in terms of intraobserver and interobserver reliability. Agreement was very good on the vertebral level, “vertebrae with kyphoplasty” level and “2 above and 1 below the kyphoplasty vertebrae” level. The application of Genant’s method to these patients also resulted in perfect agreement. We believe that the potential value of VFA in patients treated with kyphoplasty requires further evaluation, particularly comparing VFA with SR and performing a longitudinal follow-up. More research will help to adopt care processes that determine which patients require VFA and how often VFA should be performed, while also considering the impact of this technique on the cost of healthcare organizations.

Use of DXA-based technology for detection and assessment of risk of vertebral fracture in rheumatology practice

Measurement of bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) is the recommended method for diagnosis of osteoporosis and assessment of future fracture risk. However, most patients who will suffer fractures do not have osteoporosis by DXA (T-score of -2.5 or less). Bone strength, which is most closely associated with resistance to fracture, is a composite of both bone density and bone quality, and the latter is not measured by DXA. Thus, other technology is needed for non-invasive and inexpensive assessment of bone strength and fracture risk. Vertebral fractures, the most common clinical fracture in the general population, are of even greater importance in rheumatoid arthritis and other rheumatic disorders. Vertebral fracture assessment (VFA) and trabecular bone scores (TBS), two techniques which can aid prediction of future fracture risk, can be used with currently available DXA machines. Description of these techniques and their potential application to clinical rheumatology practice will be the focus of this paper.