Comparison of densitometric and radiographic vertebral fracture assessment using the algorithm-based qualitative (ABQ) method in postmenopausal women at low and high risk of fracture

274th ENMC international workshop: recommendations for optimizing bone strength in neuromuscular disorders. Hoofddorp, The Netherlands, 19-21 January 2024

The 274th ENMC workshop for optimizing bone strength in neuromuscular disorders (NMDs) was held on January 19-21, 2024. The group of participants included experts in the fields of bone health and neuromuscular medicine along with the patient voice. Bone strength represents a crucial aspect of the management of pediatric and adult patients with NMDs. Bone strength may be compromised due to different pathophysiologic mechanisms, including disrupted bone-muscle "cross-talk", loss of biomechanical loading, nutritional insufficiency, inadequate weight-bearing physical activity, muscle weakness and/or immobility, and drug treatment. While for Duchenne muscular dystrophy recommendations for evaluation and treatment of bone strength have been published, evidence on bone strength in other hereditary and acquired NMDs is scarce. Enhanced knowledge is needed to understand the development and maintenance of bone strength in patients with NMDs. This workshop aimed to develop a strategy to improve bone strength and thus prevent fractures in patients with NMDs.

Radiographic Vertebral Fracture Assessment of Vertebral Fracture by the Three-Line Method

Purpose: To evaluate the value of the three-line (TL) method in the diagnosis of vertebral fractures. Methods: 286 patients over 50 years old who received thoracolumbar X-ray examination in our hospital from 2013 to 2019 were selected and divided into three groups according to their age. The incidence and severity of vertebral fractures were measured by the TL method and Genant semi-quantitative technique by the same observer. Eight vertebrae were measured in each patient, ranging from T10 to L5. Results: The TL method was consistent with the Genant semi-quantitative method when evaluating whether patients had vertebral fractures (k >0.75), and the McNemar-bowker test showed no difference in the diagnosis between the two methods (P >0.05). However, Wilcoxon rank sum test found a difference between the two methods in assessing the severity of fractured vertebrae (P < 0.05), and the TL method was more sensitive. Conclusion: The two methods can be substituted for each other in the diagnosis of vertebral fractures. However, TL method is more sensitive in the diagnosis of the severity of spinal fractures. And the TL method is more quantitative and easier for beginners to master.

Radiological features of traumatic vertebral endplate fracture: an analysis of 194 cases with 263 vertebral fractures

BACKGROUND

The importance of identifying osteoporotic vertebral endplate or/and cortex fracture (ECF), which primarily includes endplate fracture (EPF) and vertebral anterior cortex buckling, has been recognized. However, some old traumatic ECFs with healing process in the elderly may be mistaken as osteoporotic. This study analyzes the radiological features of traumatic EPF.

METHODS

This was a retrospective analysis of 194 spine trauma patients with 263 vertebral fractures (mean age: 42.11 ± 9.82 years, 118 males and 76 females). All patients had traumatic EPF identified by X-ray/CT/MRI.

RESULTS

The involved vertebra was mostly L1 (29.7%), followed by T12 and L2. Except EPFs involved both superior and inferior endplates (12.6%), only 1.9% involved inferior endplate alone, with the majority involved superior endplate. If each endplate was divided into five segments of equal lengths (from anterior to posterior: a1, a2, m, p2, p1), the most depressed point of superior EPFs was mostly at segment-a2 (approximately 45%), followed by segment-a1 (approximately 20%) or segment-m (approximately 20%), and very rarely at segment-p1. The upper 1/3 of anterior vertebral wall was more likely to fracture, followed by middle 1/3 of anterior wall. For posterior vertebral wall fracture, 68.5% broke the bony wall surrounding the basivertebral vain. 58.6%, 30.0%, and 11.4% of vertebral fractures had <1/5, 1/5-1/3, and >1/3 vertebral body height loss. As the extent of vertebral height loss increased, the chance of having both superior and inferior EPFs also increased; however, the chance of having inferior EPF alone did not increase.

CONCLUSION

Traumatic EPF features are characterized, which may help the differentiation of traumatic and osteoporotic EPFs.

Determinants of bone health in elderly Japanese men: study design and key findings of the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) cohort study

BACKGROUND

The Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) study was launched to investigate risk factors for osteoporotic fractures, interactions of osteoporosis with other non-communicable chronic diseases, and effects of fracture on QOL and mortality.

METHODS

FORMEN baseline study participants (in 2007 and 2008) included 2012 community-dwelling men (aged 65-93 years) in Nara prefecture, Japan. Clinical follow-up surveys were conducted 5 and 10 years after the baseline survey, and 1539 and 906 men completed them, respectively. Supplemental mail, telephone, and visit surveys were conducted with non-participants to obtain outcome information. Survival and fracture outcomes were determined for 2006 men, with 566 deaths identified and 1233 men remaining in the cohort at 10-year follow-up.

COMMENTS

The baseline survey covered a wide range of bone health-related indices including bone mineral density, trabecular microarchitecture assessment, vertebral imaging for detecting vertebral fractures, and biochemical markers of bone turnover, as well as comprehensive geriatric assessment items. Follow-up surveys were conducted to obtain outcomes including osteoporotic fracture, cardiovascular diseases, initiation of long-term care, and mortality. A complete list of publications relating to the FORMEN study can be found at https://www.med.kindai.ac.jp/pubheal/FORMEN/Publications.html .

Traumatic vertebral fractures involve the anterior end plate more than the posterior end plate: A retrospective study

Traumatic end plate fractures (EPFs) refers to the EPF caused by trauma, rather than the pathological status of the end plate (EP). However, some old traumatic EPFs may be mistaken as osteoporotic in the elderly. The objective of this study is to describe the radiological features of traumatic EPF in different traumatic fracture type patients presenting in the Emergency department setting. And to compare the result with osteoporotic vertebral fracture (VF).This study retrospectively analyzed the anatomical location of acute thoracolumbar vertebral traumatic EPFs in males (age≤55 years) and females (age≤50 years). The anatomic distribution of EPFs, the anterior and posterior wall fracture were analyzed in patients, who were scanned with 1 or more of the following methods: radiography, CT, and magnetic resonance imaging.There were 194 cases of acute spine trauma involving at least 1 EPF, including 118 males and 76 females. The involved vertebra was mostly at L1 (29.7%), followed by T12 (18.3%), and then by L2 (12.9%). Excluding those with both upper and lower EP involvements, the ratio of superior EPF to inferior EPF was 33.5 for males and 45.5 for females. With the EP divided into 5 segments of equal length in the anteroposterior direction in different fracture types, fractures occurred mostly at a2 segment (71.48% for superior EPs and 7.60% for inferior EPs), followed by a1 segment (66.16% for superior EPs). The upper third of the anterior and posterior walls were most prone to fracture in traumatic vertebral fracture.Traumatic EPFs more likely involve the anterior EP more than the posterior EP and is correlated with fracture type. These characteristics may help radiologist differential diagnosis between traumatic and osteoporotic EPF.

Elderly males with or without existing osteoporotic vertebral fracture have much lower future vertebral fracture risk than elderly females: the MrOS (Hong Kong) year-4 follow-up spine radiograph study

MrOS (Hong Kong)'s year-4 follow-up shows, for subjects at baseline without vertebral deformity (VD) and endplate or/and cortex fracture (ECF), the VD progression/new VD rate during follow-up in males was half of our paired MsOS (Hong Kong) study's results. For those with VD or ECF, the VD progression/new VD was less than one sixth of females' rate.

INTRODUCTION

This study documents MrOS (Hong Kong)'s year-4 follow-up, and the results are compared with the MsOS (Hong Kong) study. Of elderly females with Genant's grade-0, -1, -2, and -3 VD, at year-4 follow-up, 4.6%, 8%, 10.6%, and 28.9% had at least one VD progression or incident VD, respectively.

METHODS

Spine radiographs of 1500 Chinese males with baseline (mean age 71.7 years, range 65-91 years) and year-4 follow-up were evaluated according to Genant's VD criteria and ECF (non-existent, ECF0; or existent, ECF1). Grade-2 VDs were divided into mild (VD2m, 25-34% height loss) and severe (VD2s, 34-40% height loss) subgroups. Study subjects were graded into eight categories: VD0/ECF0, VD1/ECF0, VD2m/ECF0, VD0/ECF1, VD1/ECF1, VD2m/ECF1, VD2s/ECF1, and VD3/ECF1. With an existing VD, a further height loss of ≥ 15% was a VD progression. A new VD incident was a change from grade-0 to grade-2/3, or to grade-1 with ≥ 10% height loss.

RESULTS

Of subjects with Genant's grade-0, 2.05% (25/1219) developed at least one VD progression or/and new VD, while of subjects with Genant's grade-1, -2, and -3 VD, only 2% (3/149), 3.1% (3/96), and 2.8% (1/36) developed at least one VD progression/new VD, respectively. Among the three ECF0 groups, there was a significant difference in new ECF incidence, with VD0/ECF0 being the lowest and VD2m/ECF0 being the highest.

CONCLUSION

VD progression/new VD is much less common in elderly men than in elderly women. Vertebrae with VD had a higher risk of developing ECF.

Osteoporotic vertebral deformity with endplate/cortex fracture is associated with higher further vertebral fracture risk: the Ms. OS (Hong Kong) study results

Compared with vertebrae without deformity, vertebrae with mild/moderate deformity have a higher risk of endplate or/and cortex fracture (ecf). Compared with subjects without ecf, subjects with ecf are at a higher risk of short-term (4-year period) deformity progression and new incident deformity.

INTRODUCTION

The progression and incidence of osteoporotic vertebral deformity/fracture (VD/VF) in elderly Chinese females remain not well documented.

METHODS

Spine radiographs of 1533 Chinese females with baseline and year-4 follow-up (mean age 75.7 years) were evaluated according to Genant's VD criteria and endplate/cortex fracture (non-existent: ecf0 or existent: ecf1). Grade-2 VDs were divided into mild (vd2m, 25-34% height loss) and severe (vd2s, 34-40% height loss) subgroups. According to their VD/VF, subjects were graded into seven categories: vd0/ecf0, vd1/ecf0, vd2m/ecf0, vd1/ecf1, vd2m/ecf1, vd2s/ecf1, and vd3/ecf1. With an existing VD, a further height loss of ≥ 15% was a VD progression. A new incident VD was a change from grade-0 to grade-2/3 or to grade-1 with ≥ 10% height loss.

RESULTS

Of subjects with Genant's grades 0, - 1, - 2, and - 3 VD, at follow-up, 4.6%, 8%, 10.6%, and 28.9% had at least one VD progression or new incident VD respectively. Among the three ecf0 groups, there was no difference in VD progression or new VD; while there was a significant difference in new ecf incidence, with vd0/ecf0 being lowest and vd2m/ecf0 being highest. Vd1/ecf0 and vd2m/ecf0 vertebrae had a higher risk of turning to ecf1 than vd0/ecf0 vertebrae. If vd1/ecf0 and vd2m/ecf0 subjects were combined together (range 20-34% height loss) to compare with vd1/ecf1 and vd2m/ecf1 subjects, the latter had significantly higher VD progression and new VD rates.

CONCLUSION

Vertebrae with grade-1/2 VDs had a higher risk of developing ECF. Subjects with pre-existing ECFs had a higher risk of worsening or new vertebral deformities.

Prevalent osteoporotic vertebral fractures more likely involve the upper endplate than the lower endplate and even more so in males

Background

While the importance of identifying osteoporotic vertebral endplate fracture (EPF) is being recognized; the pathophysiological understanding of EPF till now remain insufficient. In this population-based cross-sectional radiograph study, we aim to investigate the anatomic location characteristics of osteoporotic EPF.

Methods

This study analyzed the anatomical location of osteoporotic EPFs in elderly Chinese population (age ≥65 years). The T4-L4 radiographs of 1,954 elderly Chinese men (mean: 72.3 years) and 1,953 elderly Chinese women (mean: 72.5 years) were evaluated to identify EPF, and vertebral bodies were graded according to Genant's vertebral deformity criteria.

Results

Of the 101,582 endplates analyzed, there were 505 EPFs (males: 27.7%; females: 72.3%). Excluding those with both upper endplate and lower endplate involvements, the ratio of upper EPF to lower EPF was 9.63 for males and 4.3 for females (P<0.05). Thoracolumbar junction, particularly L1 (26.4% for males and 24.1% for females) and followed by T12 (20.7% for males and 19.7% for females), had highest prevalence of EPF. With an endplate divided into 5 segments of equal length in the anteroposterior direction and grade 0.5 & 1, grade 2 vertebral deformities analyzed, fractures occurred mostly at the middle segment (70.1% for upper endplates in males and 78.6% for upper endplates in females), followed by second anterior segment (20.9% for upper endplates in males and 14.4% for upper endplates in females). The most anterior and most posterior segments were not primarily involved in EPF.

Conclusions

Osteoporotic EPFs more likely involve the upper endplate rather than lower endplate, with a trend for this effect to be greater in men than in women. These characteristics may help radiographic differential diagnosis for osteoporotic EPF.

Osteoporotic vertebral endplate and cortex fractures: A pictorial review

Despite years' research, the radiographic criteria for osteoporotic vertebral fracture and its grading remain debated. The importance of identifying vertebral endplate/cortex fracture (ECF) is being recognised; however, evaluation of osteoporotic ECF requires training and experience. This article aims to serve as a teaching material for radiologists/physicians or researchers to evaluate osteoporotic ECF. Emphasis is particularly dedicated to identifying ECF that may not be associated with apparent vertebral body collapse. We suggest a combined approach based on standardised radiologic evaluation by experts and morphometry measurement is the most appropriate approach to detect and classify osteoporotic vertebral fractures.

The translational potential

A good understanding of radiologic anatomy of vertebrae and fracture signs of endplate/cortex are essential for spine fragility fracture assessment.

Osteoporotic Vertebral Fracture Prevalence Varies Widely Between Qualitative and Quantitative Radiological Assessment Methods: The Rotterdam Study

Accurate diagnosis of vertebral osteoporotic fractures is crucial for the identification of individuals at high risk of future fractures. Different methods for radiological assessment of vertebral fractures exist, but a gold standard is lacking. The aim of our study was to estimate statistical measures of agreement and prevalence of osteoporotic vertebral fractures in the population-based Rotterdam Study, across two assessment methods. The quantitative morphometry assisted by SpineAnalyzer® (QM SA) method evaluates vertebral height loss that affects vertebral shape whereas the algorithm-based qualitative (ABQ) method judges endplate integrity and includes guidelines for the differentiation of vertebral fracture and nonfracture deformities. Cross-sectional radiographs were assessed for 7582 participants aged 45 to 95 years. With QM SA, the prevalence was 14.2% (95% CI, 13.4% to 15.0%), compared to 4.0% (95% CI, 3.6% to 4.5%) with ABQ. Inter-method agreement according to kappa (κ) was 0.24. The highest agreement between methods was among females (κ = 0.31), participants age >80 years (κ = 0.40), and at the L₁ level (κ = 0.40). With ABQ, most fractures were found at the thoracolumbar junction (T₁₂ -L₁ ) followed by the T₇ -T₈ level, whereas with QM SA, most deformities were in the mid thoracic (T₇ -T₈ ) and lower thoracic spine (T₁₁ -T₁₂ ), with similar number of fractures in both peaks. Excluding mild QM SA deformities (grade 1 with QM) from the analysis increased, the agreement between the methods from κ = 0.24 to 0.40, whereas reexamining mild deformities based on endplate depression increased agreement from κ = 0.24 to 0.50 (p <0.001). Vertebral fracture prevalence differs significantly between QM SA and ABQ; reexamining QM mild deformities based on endplate depression would increase the agreement between methods. More widespread and consistent application of an optimal method may improve clinical care. © 2017 American Society for Bone and Mineral Research.

ACR Appropriateness Criteria® Osteoporosis and Bone Mineral Density

Osteoporosis is a considerable public health risk, with 50% of women and 20% of men >50 years of age experiencing fracture, with mortality rates of 20% within the first year. Dual x-ray absorptiometry (DXA) is the primary diagnostic modality by which to screen women >65 years of age and men >70 years of age for osteoporosis. In postmenopausal women <65 years of age with additional risk factors for fracture, DXA is recommended. Some patients with bone mineral density above the threshold for treatment may qualify for treatment on the basis of vertebral body fractures detected through a vertebral fracture assessment scan, a lateral spine equivalent generated from a commercial DXA machine. Quantitative CT is useful in patients with advanced degenerative bony changes in their spines. New technologies such as trabecular bone score represent an emerging role for qualitative assessment of bone in clinical practice. It is critical that both radiologists and referring providers consider osteoporosis in their patients, thereby reducing substantial morbidity, mortality, and cost to the health care system. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Value and potential limitations of vertebral fracture assessment (VFA) compared to conventional spine radiography: experience from a fracture liaison service (FLS) and a meta-analysis

We evaluated the value of VFA in the identification of vertebral fractures using a retrospective study and a meta-analysis. Performance of VFA was adequate in the meta-analysis although this was not demonstrated in our centre. We recommend checking the performance of VFA tools before exclusively relying on this tool.

INTRODUCTION

Vertebral fractures are traditionally diagnosed using conventional radiographs of the spine. Vertebral fracture assessment (VFA) has been advocated as an alternative tool in the diagnosis of these fractures.

METHODS

We conducted a retrospective study as well as a systematic review and a meta-analysis to evaluate the performance of VFA compared to conventional spinal radiography in patients who had sustained a fracture and thus at risk for osteoporosis. A risk of bias analysis was also performed.

RESULTS

The diagnostic study included 542 patients (25% male) with fractures. The sensitivity of low-radiation VFA to detect a patient with a vertebral fracture ≥ Genant grade 2 was 0.77 and its specificity 0.80. Two hundred ninety-seven (55%) patients had ≥1 and 135(25%) ≥3 unevaluable vertebrae. The systematic review identified 16 studies including a total of 3238 subjects (19% male) with a mean age range of 45 to 74 years. Seven studies had a low risk of bias and 9 had an intermediate risk, mainly due to not consecutively including patients. The pooled sensitivity of VFA to detect a patient with a vertebral fracture ≥Genant grade 2 was 0.84 (95% CI, 0.72-0.92) and specificity 0.90 (95% CI, 0.84-0.94).

CONCLUSIONS

Our findings from the meta-analysis suggest an adequate performance of VFA for the detection of vertebral fractures. However, we could not demonstrate these findings in our center, especially the specificity. Our data advocate caution with exclusively relying on VFA in the assessment of vertebral fractures without identifying performance and potential limitations of the technique.

Identifying osteoporotic vertebral endplate and cortex fractures

Osteoporosis is the most common metabolic bone disease, and vertebral fractures (VFs) are the most common osteoporotic fracture. A single atraumatic VF may lead to the diagnosis of osteoporosis. Prevalent VFs increase the risk of future vertebral and non-vertebral osteoporotic fracture independent of bone mineral density (BMD). The accurate and clear reporting of VF is essential to ensure patients with osteoporosis receive appropriate treatment. Radiologist has a vital role in the diagnosis of this disease. Several morphometrical and radiological methods for detecting osteoporotic VF have been proposed, but there is no consensus regarding the definition of osteoporotic VF. A vertebra may fracture yet not ever result in measurable changes in radiographic height or area. To overcome these difficulties, algorithm-based qualitative approach (ABQ) was developed with a focus on the identification of change in the vertebral endplate. Evidence of endplate fracture (rather than variation in vertebral shape) is the primary indicator of osteoporotic fracture according to ABQ criteria. Other changes that may mimic osteoporotic fractures should be systemically excluded. It is also possible that vertebral cortex fracture may not initially occur in endplate. Particularly, vertebral cortex fracture can occur in anterior vertebral cortex without gross vertebral deformity (VD), or fractures deform the anterior vertebral cortex without endplate disruption. This article aims to serve as a teaching material for physicians or researchers to identify vertebral endplate/cortex fracture (ECF). Emphasis is particularly dedicated to identifying ECF which may not be associated apparent vertebral body collapse. We believe a combined approach based on standardized radiologic evaluation by experts and morphometry measurement is the most appropriate approach to detect and classify VFs.

Misdiagnosis of vertebral fractures on local radiographic readings of the multicentre POINT (Prevalence of Osteoporosis in INTernal medicine) study

BACKGROUND

Osteoporotic vertebral fractures (VFs) are often misdiagnosed because asymptomatic and occurring in the absence of specific trauma. Further, diagnostic assessment of VFs may be suboptimal.

AIM OF THE STUDY

To assess the misdiagnosis of vertebral fractures on local radiographic readings in the cohort of patients enrolled in the POINT study.

METHODS

We enrolled hospitalised patients, admitted for any cause to the Internal Medicine Units of 37 hospitals participating to the cross-sectional previously published POINT study. The assessment of VFs was performed both by local radiologists and by two expert skeletal radiologists, by using semiquantitative method (SQ). To better evaluate mild vertebral deformities, the two central radiologists also used the algorithm-based qualitative assessment (ABQ).

RESULTS

The radiographs of 661 patients (401 females; mean age 75.8±8.0) were evaluated. The inter-reader percent agreement between two central expert radiologists per-vertebra assessment was excellent (99.78%; k=0.984; 95% CI, 0.977-0.991). Central reading identified 318/661 (48.1%) patients with at least one VF. Local and central readings agreed in 502/661 (75.9%) patients, resulting in a fair reproducibility (k=0.52; 95% confidence interval 0.44-0.59). Diagnostic performance parameters of local readings were: sensitivity 76.1%; specificity 75.8%; PPV 74.46%; NPV 77.38%). By examining 9254 vertebrae, central and local readers diagnosed 665 (7.2%) and 562 (6.1%) VFs respectively. Misdiagnosis (102 false positives and 205 false negatives) mainly occurred for mild VFs. Local readings identified correctly 460 out 665 VFs diagnosed by central readings, resulting in sensitivity of 69.2% and PPV of 81.8%.

CONCLUSIONS

Following a standardized protocol of acquisition techniques and of interpretation criteria, an excellent agreement between local and central readings for moderate and severe vertebral fractures resulted. However a significant amount of mild vertebral fractures, that are the most of VFs, were misdiagnosed by local radiologists. In order to improve VFs assessment, the radiologists should be trained and sensitized in relation to the relevant clinical significance of osteoporotic VFs identification.

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.

Vertebral fractures assessment in children: Evaluation of DXA imaging versus conventional spine radiography

Vertebral fracture assessment (VFA) by DXA is an accepted tool in adults. However, its use in children has not been assessed. The aim of this study was to evaluate DXA VFA and morphometric analysis (MXA) using a GE Lunar iDXA bone densitometer against spinal radiographic assessment (RA) for the identification of vertebral fractures in children. Spine RA and VFA (T3-L5) were acquired on the same day in 80 children. Forty children considered high risk for fracture by their metabolic bone specialist were referred for spinal RA. Another 40 children were recruited as part of a prospective fracture study and were considered low risk for vertebral fracture. Agreement between RA and VFA was assessed by an expert paediatric radiologist and two paediatricians with expertise in bone pathology. Agreement between RA and MXA was assessed by an expert paediatric radiologist, two clinical scientists and an experienced paediatric radiographer. Vertebrae were ranked as normal, mild, moderate or severe if they had <10%, 11-25%, 26-50% and >50% deformity, respectively. Levels of agreement were calculated using the Cohen kappa score. Evaluating the data from all readable vertebrae, 121 mild, 44 moderate and 16 severe vertebral fractures were identified; with 26, 8, and 5 subjects having at least one mild, moderate or severe fracture, respectively. Depending on rater, 92.8-94.8% of the vertebrae were evaluable by RA. In contrast, 98.4% were evaluable by VFA and only 83.6% were evaluable by MXA. Moderate agreement was found between raters for RA [kappa 0.526-0.592], and VFA [kappa 0.601-0.658] and between RA and VFA [kappa 0.630-0.687]. In contrast, only slight agreement was noted between raters for MXA [kappa 0.361-0.406] and between VFA and MXA [kappa 0.137-0.325]. Agreement substantially improved if the deformities were dichotomised as normal or mild versus moderate or severe [kappa 0.826-0.834]. For the detection of moderate and/or severe fractures the sensitivities & specificities were 81.3% & 99.3%, and 62.5% & 99.2% for VFA and MXA, respectively. This study demonstrates that VFA is as good as RA for detecting moderate and severe vertebral fractures. Given the significant radiation dose saving of VFA compared with RA, VFA is recommended as a diagnostic tool for the assessment of moderate or severe vertebral fracture in children.

A systematic review of diagnostic accuracy of vertebral fracture assessment (VFA) in postmenopausal women and elderly men

This systematic review was performed to compare the diagnostic accuracy of vertebral fracture assessment (VFA) with that of spinal radiography for identification of vertebral fractures (VFs). VFA appeared to have moderate sensitivity and high specificity for detecting VFs when compared with spinal radiography.

INTRODUCTION

VFs are recognized as the hallmark of osteoporosis, and a previous VF increases the risk of a future fracture. Therefore, the timely detection of VFs is important for prevention of further fractures. This systematic review examined the diagnostic accuracy of VFA using dual X-ray absorptiometry (DXA) to identify VFs.

METHODS

We searched for potentially relevant studies using electronic databases, including Ovid-Medline, Ovid-EMBASE, Cochrane library, and four Korean databases, from their inception to May 2013. We compared the diagnostic accuracy of VFA with that of spinal radiography for detection of VFs by analyzing the sensitivity and specificity using a 2 × 2 contingency table. Subgroup analyses were also performed on studies with a low risk of bias and applicability.

RESULTS

Twelve studies were analyzed for the diagnostic accuracy of VFA. The sensitivity and specificity were 0.70-0.93 and 0.95-1.00, respectively, analyzed on a per-vertebra basis, and 0.65-1.00 and 0.74-1.00 on a per-patient basis. The sensitivity and specificity of five studies in subgroups with a low risk of bias in the intervention test were 0.70-0.84 and 0.96-0.99, respectively. In studies with a low risk of bias in the patient selection, those based on a per-vertebra basis in three studies were 0.70-0.93 and 0.96-1.00, respectively.

CONCLUSIONS

VFA had moderate sensitivity and high specificity for detecting VF when compared with spinal radiography. However, the present findings are insufficient to assess whether spinal radiography should be replaced by VFA.

A critical appraisal of vertebral fracture assessment in paediatrics

PURPOSE

There is a need to improve our understanding of the clinical utility of vertebral fracture assessment (VFA) in paediatrics and this requires a thorough evaluation of its readability, reproducibility, and accuracy for identifying VF.

METHODS

VFA was performed independently by two observers, in 165 children and adolescents with a median age of 13.4 years (range, 3.6, 18). In 20 of these subjects, VFA was compared to lateral vertebral morphometry assessment on lateral spine X-ray (LVM).

RESULTS

1528 (84%) of the vertebrae were adequately visualised by both observers for VFA. Interobserver agreement in vertebral readability was 94% (kappa, 0.73 [95% CI, 0.68, 0.73]). 93% of the non-readable vertebrae were located between T6 and T9. Interobserver agreement per-vertebra for the presence of VF was 99% (kappa, 0.85 [95% CI, 0.79, 0.91]). Interobserver agreement per-subject was 91% (kappa, 0.78 [95% CI, 0.66, 0.87]). Per-vertebra agreement between LVM and VFA was 95% (kappa 0.79 [95% CI, 0.62, 0.92]) and per-subject agreement was 95% (kappa, 0.88 [95% CI, 0.58, 1.0]). Accepting LVM as the gold standard, VFA had a positive predictive value (PPV) of 90% and a negative predictive value (NPV) of 95% in per-vertebra analysis and a PPV of 100% and NPV of 93% in per-subject analysis.

CONCLUSION

VFA reaches an excellent level of agreement between observers and a high level of accuracy in identifying VF in a paediatric population. The readability of vertebrae at the mid thoracic region is suboptimal and interpretation at this level should be exercised with caution.

Reproducibility of Vertebral Fracture Assessment Readings From Dual-energy X-ray Absorptiometry in Both a Population-based and Clinical Cohort: Cohen's and Uniform Kappa

Vertebral fracture assessments (VFAs) using dual-energy X-ray absorptiometry increase vertebral fracture detection in clinical practice and are highly reproducible. Measures of reproducibility are dependent on the frequency and distribution of the event. The aim of this study was to compare 2 reproducibility measures, reliability and agreement, in VFA readings in both a population-based and a clinical cohort. We measured agreement and reliability by uniform kappa and Cohen's kappa for vertebral reading and fracture identification: 360 VFAs from a population-based cohort and 85 from a clinical cohort. In the population-based cohort, 12% of vertebrae were unreadable. Vertebral fracture prevalence ranged from 3% to 4%. Inter-reader and intrareader reliability with Cohen's kappa was fair to good (0.35-0.71 and 0.36-0.74, respectively), with good inter-reader and intrareader agreement by uniform kappa (0.74-0.98 and 0.76-0.99, respectively). In the clinical cohort, 15% of vertebrae were unreadable, and vertebral fracture prevalence ranged from 7.6% to 8.1%. Inter-reader reliability was moderate to good (0.43-0.71), and the agreement was good (0.68-0.91). In clinical situations, the levels of reproducibility measured by the 2 kappa statistics are concordant, so that either could be used to measure agreement and reliability. However, if events are rare, as in a population-based cohort, we recommend evaluating reproducibility using the uniform kappa, as Cohen's kappa may be less accurate.

Prevalence of vertebral fractures and minor vertebral deformities evaluated by DXA-assisted vertebral fracture assessment (VFA) in a population-based study of postmenopausal women: the FRODOS study

Population-based studies performed with vertebral fracture assessment (VFA) morphometric technology are lacking in postmenopausal osteoporosis. In this study, we show a lower than expected prevalence of vertebral fractures, a high prevalence of minor vertebral deformities, and a clear association with clinical and densitometric parameters indicating the usefulness of this approach.

INTRODUCTION

Adequate epidemiological data on the prevalence of vertebral fractures (VF) is essential in studies of postmenopausal osteoporosis. Routine DXA-assisted VFA may be useful to determine the presence of VF. However, population-based studies performed with this technology are lacking. We aimed to assess the prevalence of VF and minor deformities in 2,968 postmenopausal women aged 59-70 years from a population-based cohort.

METHODS

VFA and bone mineral density (BMD) measurements were conducted, and McCloskey criteria (vertebral heights under 3 SD from reference values) confirmed with the Genant method were used to define VF. Additionally, minor vertebral deformities (vertebral heights between -2 and -2.99 SD) were evaluated.

RESULTS

The prevalence of VF was 4.3%, and 17% of the participants had minor vertebral deformities. Low BMD was frequently observed in women with VF, with 4%, and 42% of participants showing osteoporosis and osteopenia. Minor vertebral deformities were observed in nearly 40% of women with VF. Multivariate logistic regression analysis showed that age, history of previous fracture, osteoporotic BMD, receiving anti-osteoporotic treatment, and current use of glucocorticoids were significantly associated with VF.

CONCLUSIONS

Although the VFA approach showed a lower than expected prevalence of VF in our cohort, its association with clinical and densitometric parameters may be useful to identify women at risk for developing fragility fractures and may therefore justify its use in longitudinal studies. The high prevalence of minor vertebral deformities detected in patients with VF indicates the need to evaluate this type of deformity as a risk factor for further skeletal fractures.

Trabecular bone score (TBS) predicts vertebral fractures in Japanese women over 10 years independently of bone density and prevalent vertebral deformity: the Japanese Population-Based Osteoporosis (JPOS) cohort study

Bone strength is predominantly determined by bone density, but bone microarchitecture also plays an important role. We examined whether trabecular bone score (TBS) predicts the risk of vertebral fractures in a Japanese female cohort. Of 1950 randomly selected women aged 15 to 79 years, we analyzed data from 665 women aged 50 years and older, who completed the baseline study and at least one follow-up survey over 10 years, and who had no conditions affecting bone metabolism. Each survey included spinal imaging by dual-energy X-ray absorptiometry (DXA) for vertebral fracture assessment and spine areal bone mineral density (aBMD) measurement. TBS was obtained from spine DXA scans archived in the baseline study. Incident vertebral fracture was determined when vertebral height was reduced by 20% or more and satisfied McCloskey-Kanis criteria or Genant's grade 2 fracture at follow-up. Among eligible women (mean age 64.1 ± 8.1 years), 92 suffered incident vertebral fractures (16.7/10(3) person-years). These women were older with lower aBMD and TBS values relative to those without fractures. The unadjusted odds ratio of vertebral fractures for one standard deviation decrease in TBS was 1.98 (95% confidence interval [CI] 1.56, 2.51) and remained significant (1.64, 95% CI 1.25, 2.15) after adjusting for aBMD. The area under the receiver operating characteristic curve of TBS and aBMD combined was 0.700 for vertebral fracture prediction and was not significantly greater than that of aBMD alone (0.673). However, reclassification improvement measures indicated that TBS and aBMD combined significantly improved risk prediction accuracy compared with aBMD alone. Further inclusion of age and prevalent vertebral deformity in the model improved vertebral fracture prediction, and TBS remained significant in the model. Thus, lower TBS was associated with higher risk of vertebral fracture over 10 years independently of aBMD and clinical risk factors including prevalent vertebral deformity. TBS could effectively improve fracture risk assessment in clinical settings.

Systematic vertebral fracture assessment in asymptomatic postmenopausal women

INTRODUCTION

Recognition of vertebral fractures (VFs) changes the patient's diagnostic classification, estimation of fracture risk, and threshold for pharmacological intervention. Vertebral fracture assessment (VFA) enables the detection of VFs in the same session as bone mineral density (BMD) testing.

OBJECTIVE

To study prevalence and risk factors of VFs using VFA in asymptomatic women and measure its effect on treatment recommendations.

METHODS

We enrolled 908 postmenopausal women (mean age, weight and BMI of 60.9 ± 7.7 (50-91) years, 73.2 ± 13.2 (35-150) kg and 29.8 ± 5.3 (14.5-50.8) kg/m(2), respectively. Lateral VFA images and scans of the lumbar spine and proximal femur were obtained using a GE Healthcare Lunar Prodigy densitometer. VFs were defined using a combination of Genant semiquantitative (SQ) approach and morphometry.

RESULTS

VFs were identified in 382 patients (42.0%): 203 (22.3%) had grade 1 and 179 (19.7%) had grade 2 or 3. The prevalence of VFA-detected fractures globally increased significantly with age and as BMI and BMD declined. A fracture was identified on VFA in 63 (28.3%) women with normal BMD (8.5% had grade 2/3 VFs) and in 145 (38.5%) with osteopenia (15.7% had grade 2/3 VFs). Stepwise regression analysis showed that presence of VFs was independently related to age, BMI, number of parity, history of peripheral fracture and lumbar spine BMD.

CONCLUSION

A high proportion of women with asymptomatic VFs would not receive treatment if screening were based only on BMD evaluation. Our results support the recommendation to enlarge the indications of VFA in the presence of risk factors such as age over 60, multiparity, history of peripheral traumatic fractures and low BMI.

Diagnostic performance of vertebral fracture assessment by the lunar iDXA scanner compared to conventional radiography

The purpose of this study was to evaluate the diagnostic performance of vertebral fracture assessment (VFA) using the Lunar iDXA scanner. Conventional spinal radiographs and images acquired by dual-energy X-ray absorptiometry (DXA) of 350 subjects (269 females, 81 males) were evaluated by two different readers. We visualized 4,476/4,550 (98.4 %) vertebrae from T4 to L4 on VFA images compared to 4,535/4,550 (99.7 %) on radiographs. Among the visualized vertebrae, 205/4,535 (4.5 %) and 190/4,476 (4.2 %) were identified as nonfracture deformities by reading of radiographs and VFA, respectively. Vertebral fractures (VFs) were 231 in 126 patients and 228 in 125 patients by semiquantitative assessment of radiographs (SQ-Rx) and by VFA, respectively. There was excellent agreement between the two techniques and high diagnostic performance of VFA both on a per-vertebra basis (k score = 0.984, 95 % CI 0.972-0.996, sensitivity 98.68 %, specificity 99.91 %, PPV 98.25 %, NPV 99.93 %) and on a per-patient basis (k score = 0.957, 95 % CI 0.925-0.988, sensitivity 96.83 %, specificity 98.66 %, PPV 97.60 %, NPV 98.22 %). In older patients (≥65 years) affected by moderate or severe osteoarthritis, SQ-Rx and VFA identified 96 VFs and 95 versus 90 vertebral deformities, respectively. This study demonstrates that most vertebrae are evaluable using the iDXA scanner, with improved VFA diagnostic performance even in discriminating mild VFs from vertebral deformities. Therefore, VFA may be appropriate as an alternative to conventional radiography in patients at high risk of VF who are undergoing DXA bone densitometry and in the follow-up of osteoporotic patients on treatment.

Supine vs decubitus lateral patient positioning in vertebral fracture assessment

In vertebral fracture assessment (VFA), lateral scans are obtained with the patient positioned supine (C-arm densitometers) or lateral decubitus (fixed-arm densitometers). We aimed to determine the impact of positioning on image quality and fracture definition. We performed supine and decubitus lateral VFA in 50 postmenopausal women and used the algorithm-based qualitative method to identify vertebral fractures. We compared the 2 techniques for the identification of fractures (kappa analysis) and compared the numbers of unreadable vertebrae (indiscernible endplates) and vertebrae that were projected obliquely (Wilcoxon matched-pairs signed-rank test). The kappa score for agreement between the VFA techniques (to identify women with vertebral fractures) was 0.84 (95% confidence interval [CI]: 0.68-0.99), and for agreement with fracture assessments made from radiographs, kappa was 0.76 (95% CI: 0.57-0.94) for both supine and decubitus lateral VFA. There were more unreadable vertebrae with supine lateral (48 vertebrae in supine lateral compared with 14 in decubitus lateral; p=0.001), but oblique projection was less common (93 vertebrae compared with 145 in decubitus lateral; p=0.002). We conclude that there were significantly different projection effects with supine and decubitus lateral VFA, but these differences did not influence the identification of vertebral fractures in our study sample.

Anatomical distribution of vertebral fractures: comparison of pediatric and adult spines

SUMMARY

We compared the distribution of vertebral fractures in adults and children and found that fractures occurred in different locations in the two age groups. This likely relates to the different shape of the immature spine.

INTRODUCTION

We hypothesized that the anatomical distribution of vertebral fractures (VF) would be different in children compared to adults.

METHODS

We compared the distribution of VF defined using the Genant semi-quantitative method (GSQ method) in adults (N = 221; 545 fractures) and in children early in the course of glucocorticoid therapy (N = 44; 94 fractures).

RESULTS

The average age in the adult cohort was 62.9 years (standard deviation (SD), 13.4 years), 26% was male, the mean lumbar spine Z-score was -1.0 (SD, 1.5), and the corresponding T-score was -2.4 (SD, 1.4). The pediatric cohort median age was 7.7 years (range, 2.1-16.6 years), the mean lumbar spine Z-score was -1.7 (SD, 1.5), 52% was male, and disease categories were acute lymphoblastic leukemia (66%), rheumatological conditions (21%), and nephrotic syndrome (14%). The VF distribution was biphasic in both populations, but the peaks differed in location. In adults, the peaks were at T7/T8 and at T12/L1. In children, the focus was higher in the thoracic spine, at T6/T7, and lower in the lumbar spine, at L1/L2. When children were assessed in two age-defined sub-groups, a biphasic VF distribution was seen in both, but the upward shift of the thoracic focus to T6 was observed only in the older group, with the highest rates of fracture present between ages 7 and 10 years.

CONCLUSIONS

These results suggest that the anatomical distribution of VF differs between children and adults, perhaps relating to the different shape of the immature spine, notably the changing ratio of kyphosis to lordosis.

Vertebral fracture assessment in asymptomatic men and its impact on management

INTRODUCTION

Recognition of vertebral fractures (VFs) change the patient's diagnostic classification, estimation of fracture risk, and threshold for pharmacological intervention. Vertebral fracture assessment (VFA) enables the detection of VFs in the same session as bone mineral density (BMD) testing.

OBJECTIVE

To study prevalence and risk factors of VFs using VFA in asymptomatic men and measure its impact on patients' management.

METHODS

We enrolled 791 men aged between 45 and 89 (mean age, weight and BMI of 62.4±8.6) (45 to 89) years, 74.9±12.7 (40 to 163) and 26.3±4.0 (16.6 to 43.8) kg/m(2), respectively. Lateral VFA images and scans of the lumbar spine and proximal femur were obtained using a GE Healthcare Lunar Prodigy densitometer. VFs were defined using a combination of Genant semiquantitative (SQ) approach and morphometry.

RESULTS

VFs were identified in 318 (40.3%): 206 (26.0%) had grade 1 and 112 (14.2%) had grade 2 or 3. As would be expected, the prevalence of VFA-detected fractures globally increased significantly with age and as BMI and BMD declined. A fracture was identified on VFA in 85 (32.4%) of men with normal BMD (6.9% had grade 2/3 VFs) and in 144 (35.8%) with osteopenia (11.7% had grade 2/3 VFs). Stepwise regression analysis showed that presence of VFs was independently related to the osteoporotic status (OR=4.761, 95%CI [2.956-7.668]; p<0.0001) and current smoking (OR=1.717, 95%CI [1.268-2.323]; p=0.002).

CONCLUSION

Our results support the recommendation to enlarge the indications of VFA to all the men referred for DXA measurement.

Association between incident and baseline vertebral fractures in European women: vertebral fracture assessment in the Osteoporosis and Ultrasound Study (OPUS)

Vertebral fracture assessment (VFA) with densitometric devices uses less radiation than spinal radiography. We assessed risk of new vertebral fracture (VF) in women with baseline fracture identified on VFA using algorithm-based qualitative diagnosis. Women with VF had significantly greater risk of VF after 6 years compared to those without baseline fracture.

INTRODUCTION

Prevalent VFs predict future fracture and are identifiable on vertebral fracture assessment (VFA) using bone densitometry devices. We have previously performed cross-sectional, but not longitudinal, VFA using the algorithm-based qualitative method (ABQ). We aimed to examine the prevalence and incidence of VF and test the association between prevalent and incident VF identified by ABQ VFA.

METHODS

We used ABQ to assess vertebral images obtained at baseline and 6 years (Hologic devices) in 674 women at ages 39 to 80 years participating in the Osteoporosis and Ultrasound Study. Criteria for prevalent and incident VF were endplate fracture, with/without cortical fracture. We compared proportions (chi-squared test) and characteristics (two-sample t tests and analysis of variance) of women with and without VF and calculated odds ratios for incident VF in women with prevalent VF (logistic regression).

RESULTS

Prevalent VF was identified in one premenopausal woman and 41 postmenopausal women. Incident VF was identified in 18 postmenopausal women. Odds ratios (95% CI) for incident VF in postmenopausal women with prevalent VF were 7.8 (2.8, 22.1) (unadjusted) and 4.3 (1.4, 13.7) (adjusted for age and bone mineral density, BMD). Women with prevalent or incident VF were older (P < 0.01), with lower hip BMD (P < 0.001) compared to women without VF.

CONCLUSIONS

Population-based postmenopausal women had relatively low prevalence and incidence of VF analysed with the ABQ method applied to VFA. Women with prevalent fracture had a significantly greater risk of incident VF than women without prevalent fracture.

Vertebral fractures and the misclassification of osteoporosis in men with prostate cancer

Androgen deprivation therapy (ADT) has become the cornerstone of treatment for both advanced and nonmetastatic prostate cancer. The presence of a nontraumatic vertebral fracture (VF) identifies a patient who has clinical osteoporosis. Vertebral fracture analysis (VFA), a dual-energy X-ray absorptiometry (DXA)-based technology identifies VFs in conjunction with a standard bone mineral density (BMD) examination. The objective of this study was to determine if VFA would increase the diagnosis of osteoporosis in men with prostate cancer on ADT. One hundred sixteen men aged ≥ 60yrs with nonmetastatic prostate cancer receiving ADT for ≥ 6mos underwent DXA of the spine, hip, and 1/3 distal radius, VFA, and conventional vertebral X-rays. Approximately 40% of the men had clinically defined osteoporosis. The use of conventional DXA criteria (spine and hip) alone resulted in the misdiagnosis of approx 75% of patients. VFA and addition of the 1/3 distal radius site performed by DXA both increased the rate of diagnosis and reduced the misclassification of osteoporosis in men with prostate cancer, compared with conventional DXA criteria alone. Analysis indicated that VFA assessment of mild, moderate, and severe fractures from all readable vertebrae (T5-L4) had a kappa statistic, sensitivity, and specificity of 0.92, 100%, and 95%, respectively, with semiquantitative radiography. Men with prostate cancer on ADT should be screened for osteoporosis at the initiation of therapy, and evaluation should include DXA of the 1/3 distal radius in addition to the spine and hip, as well as evaluation for VFs.

Detection of vertebral fractures in DXA VFA images using statistical models of appearance and a semi-automatic segmentation

SUMMARY

Morphometric methods of vertebral fracture diagnosis lack specificity. We used detailed shape and image texture model parameters to improve the specificity of quantitative fracture identification. Two radiologists visually classified all vertebrae for system training and evaluation. The vertebral endplates were located by a semi-automatic segmentation method to obtain classifier inputs.

INTRODUCTION

Vertebral fractures are common osteoporotic fractures, but current quantitative detection methods (morphometry) lack specificity. We used detailed shape and texture information to develop more specific quantitative classifiers of vertebral fracture to improve the objectivity of vertebral fracture diagnosis. These classifiers require a detailed segmentation of the vertebral endplate, and so we investigated the use of semi-automated segmentation methods as part of the diagnosis.

METHODS

The vertebrae in a training set of 360 dual energy X-ray absorptiometry images were manually segmented. The shape and image texture of vertebrae were statistically modelled using Appearance Models. The vertebrae were given a gold standard classification by two radiologists. Linear discriminant classifiers to detect fractures were trained on the vertebral appearance model parameters. Classifier performance was evaluated by cross-validation for manual and semi-automatic segmentations, the latter derived using Active Appearance Models (AAM). Results were compared with a morphometric algorithm using the signs test.

RESULTS

With manual segmentation, the false positive rates (FPR) at 95% sensitivity were: 5% (appearance) and 18% (morphometry). With semi-automatic segmentations the sensitivities at 5% FPR were: 88% (appearance) and 79% (morphometry).

CONCLUSION

Specificity and sensitivity are improved by using an appearance-based classifier compared to standard height ratio morphometry. An overall sensitivity loss of 7% occurs (at 95% specificity) when using a semi-automatic (AAM) segmentation compared to expert annotation, due to segmentation error. However, the classifier sensitivity is still adequate for a computer-assisted diagnosis system for vertebral fracture, especially if used in a triage approach.

Prevalent vertebral deformity independently increases incident vertebral fracture risk in middle-aged and elderly Japanese women: the Japanese Population-based Osteoporosis (JPOS) Cohort Study

SUMMARY

Prevalent vertebral deformity increases incident vertebral fracture risk according to studies focusing primarily on Caucasian elderly populations. We report a 3-fold increase in this risk in a population-based cohort of Japanese women after adjusting for subject propensity for having vertebral deformities. This relationship tended to be stronger in middle-aged women.

INTRODUCTION

Evidence on increased risk of incident vertebral fractures associated with vertebral deformity in middle-aged women is limited. We aimed to evaluate this risk in a population-based cohort of Japanese women.

METHODS

We followed 712 women aged 50-79 years at baseline randomly selected from 3 municipalities in Japan for 6 years. McCloskey-Kanis criteria identified vertebral deformities on X-ray absorptiometric images. At follow-up, vertebra with > or = 20% height reduction from baseline were considered incident fractures. Rate ratio (RR) of incident fracture for prevalent vertebral deformities was calculated using the Poisson regression equation adjusted for propensity of having vertebral deformities based on potential risk factors.

RESULT

Vertebral fractures occurred in 73 women (10.3%). Crude RR of vertebral deformity-associated fracture was 4.63 [95% confidence interval (CI), 3.04-7.04] and decreased to 2.96 (95% CI, 1.77-4.94) after propensity score adjustment. Adjusted RR was generally greater in younger women at 7.19 (95% CI, 1.04-49.6), 3.19 (95% CI, 1.27-7.97), and 2.34 (95% CI, 1.33-4.11) for women aged 50-59, 60-69, and 70-79 years, respectively (p = 0.0527 for those aged 50-59 vs 70-79).

CONCLUSION

Vertebral deformity was associated with a 3-fold increase in subsequent vertebral fracture risk in Japanese women, and this association was stronger in middle-aged women.

Vertebral morphometry

Visual semiquantitative (SQ) assessment of the radiographs by a trained and experienced observer is the "gold standard" method to detect vertebral fractures. Vertebral morphometry is a quantitative method to identify osteoporotic vertebral fractures based on the measurement of vertebral heights. Vertebral morphometry may be performed on conventional spinal radiographs (MRX: morphometric x-ray radiography) or on images obtained from dual x-ray absorptiometry (DXA) scans (MXA: morphometric x-ray absorptiometry). Vertebral fracture assessment (VFA) indicates the method for identification of the vertebral fractures using lateral spine views acquired by DXA, with low-dose exposition. For epidemiologic studies and clinical drug trials in osteoporosis research but also in clinical practice, the preferred method is radiographic SQ assessment., because an expert eye can better distinguish between true fractures and vertebral anomalies than can quantitative morphometry. However, vertebral morphometry, calculating the deformity of overall thoracic and lumbar spine, may supply useful data about the vertebral fracture risk. VFA performed during routine densitometry allows identification, by visual or morphometric methods, of most osteoporotic vertebral fractures, even those that are asymptomatic.

Vertebral fracture assessment: impact of instrument and reader

PURPOSE

Many osteoporotic vertebral fractures are not clinically recognized but increase fracture risk. We hypothesized that a newer generation densitometer increases the number of evaluable vertebrae and vertebral fractures detected. We also explored the impact of reader experience on vertebral fracture assessment (VFA) interpretation.

METHODS

VFA images obtained using Prodigy and iDXA densitometers in 103 older adults were evaluated for vertebral visualization and fracture presence in the T4-L5 region. A "true" read for each densitometer was achieved by consensus. If readers disagreed, the evaluation of a third expert physician was taken as true. Main outcomes were evaluable vertebrae, vertebral fractures, and intrareader/interreader reproducibility.

RESULTS

Using the "true" reads, 92% of vertebrae were visualized on iDXA and 76% on Prodigy. Numerically, more fractures were identified with iDXA; the "true" reads found 43 fractures on iDXA and 21 on Prodigy. The experienced reader had better intrareader and interreader reproducibility than the inexperienced reader when compared with the "true" read.

CONCLUSIONS

Using the newer iDXA densitometer for VFA analysis improves vertebral body visualization and fracture detection. Training and experience enhance result reproducibility.

Vertebroplasty: only small cement volumes are required to normalize stress distributions on the vertebral bodies

STUDY DESIGN.: Biomechanical study of vertebroplasty in cadaver motion segments. OBJECTIVES.: To determine how the volume of injected cement influences: (a) stress distributions on fractured and adjacent vertebral bodies, (b) load-sharing between the vertebral bodies and neural arch, and (c) cement leakage. SUMMARY OF BACKGROUND DATA.: Vertebroplasty is increasingly used to treat vertebral fractures, but there are problems concerning adjacent level fracture and cement leakage, both of which may depend on the volume of injected cement. METHODS.: Nineteen thoracolumbar motion segments from 13 cadavers (42-91 years) were loaded to induce fracture. Fractured vertebrae received 2 sequential injections (VP1 and VP2) of 3.5 cm of polymethylmethacrylate cement. Before and after each intervention, motion segment stiffness was measured in compression and in bending, and "stress profilometry" was used to quantify the distribution of compressive stress in the intervertebral disc (which presses equally on fractured and adjacent vertebrae). Stress profiles were obtained by pulling a pressure transducer through the disc while the motion segment was compressed in flexed and extended postures. Stress profiles yielded the intradiscal pressure (IDP), the magnitude of stress peaks in the anterior and posterior (SPP) anulus, and the percentage of the applied compressive force resisted by the neural arch (FN). Cement leakage and vertebral body volume were quantified using water-immersion, and the percentage cement fill was estimated. RESULTS.: Bending and compressive stiffness fell by 37% and 50% respectively following fracture, and were restored only after VP2. Depending on posture, IDP fell by 59-85% after fracture whereas SPP increased by 107- 362%. VP1 restored IDP and SPP to prefracture values, and VP2 produced no further changes. Fracture increased FN from 11% to 39% in flexion, and from 33% to 59% in extension. FN was restored towards prefracture values only after VP2. Cement leakage increased after VP2 and was negatively correlated to vertebral body volume. Following VP2, increases in IDP and compressive stiffness were proportional to percentage fill. CONCLUSION.: About 3.5 cm of PMMA largely restored normal stress distributions to fractured and adjacent vertebral bodies, but 7 cm were required to restore motion segment stiffness and load-sharing between the vertebral bodies and neural arch. Cement leakage, IDP and compressive stiffness all increased with percentage fill.

Vertebral fracture assessment in healthy men: prevalence and risk factors

INTRODUCTION

Vertebral fracture assessment (VFA) is a technology that can reliably and accurately diagnose vertebral fractures with greater patient convenience, less radiation exposure, and lower cost than standard spine radiography.

OBJECTIVE

To study prevalence and risk factors of vertebral fractures using VFA in healthy men.

METHODS

The study cohort consists of a population of 216 healthy men aged between 50 and 79 (mean age, weight and BMI of 63.8 years, 73.3 kg and 25.7 kg/m2, respectively). Lateral VFA images and scans of the lumbar spine and proximal femur were obtained by two technologists using a GE Healthcare Lunar Prodigy densitometer. Vertebral fractures were defined using a combination of Genant semiquantitative (SQ) approach and morphometry.

RESULTS

Ninety-three percent of vertebrae from T4-L4 and 98% from T8-L4 were adequately visualized on VFA. Vertebral fractures were detected in 29.6% (64/216) of these men: 34/216 (15.7%) had grade 1 and 30/216 (13.8%) had grades 2 or 3. Twenty one of men with VFA-identified fracture (32.8%) had only a single vertebral fracture, while the other 67.2% had two or more. Fractures were most common in the mid-thoracic spine and at the thoraco-lumbar junction. As would be expected, the prevalence of VFA-detected fractures increased with age and as BMD declined. This group of men had a statistically significant lower weight, height, calcium consumption and T-score than those without a VFA-identified vertebral fracture. Regression analysis showed that presence of vertebral fracture was mainly related to the osteoporotic status (OR: 9.0; 95% CI: 3.5-22.8).

CONCLUSION

VFA allows evaluation of the majority of vertebral bodies in men. Vertebral fractures are common in healthy men and are related to low BMD.