Vertebral Fractures: Which Radiological Criteria Are Better Associated With the Clinical Course of Osteoporosis?

STUDY PURPOSE: Morphometric methods categorize potential osteoporotic vertebral fractures (OVF) on the basis of loss of vertebral height. A particular example is the widely used semiquantitative morphometric tool proposed by Genant (GSQ). A newer morphologic algorithm-based qualitative (mABQ) tool focuses on vertebral end-plate damage in recognizing OVF. We used data from both sexes in the Canadian Multicentre Osteoporosis Study (CaMos) to compare the 2 methods in identifying OVF at baseline and during 10 years of follow-up. MATERIALS AND METHODS: We obtained lateral thoracic and lumbar spinal radiographs (T4-L4) 3 times, at 5-year intervals, in 828 participants of the population-based CaMos. Logistic regressions were used to study the association of 10-year changes in bone mineral density (BMD) with incident fractures. RESULTS: At baseline, 161 participants had grade 1 and 32 had grade 2 GSQ OVF; over the next 10 years, only 9 of these participants had sustained incident GSQ OVF. Contrastingly, 21 participants at baseline had grade 1 and 48 grade 2 mABQ events; over the next 10 years, 79 subjects experienced incident grade 1 or grade 2 mABQ events. Thus, incident grades 1 and 2 morphologic fractures were 8 times more common than morphometric deformities alone. Each 10-year decrease of 0.01 g/cm2 in total hip BMD was associated with a 4.1% (95% CI: 0.7-7.3) higher odds of having an incident vertebral fracture. CONCLUSIONS: This analysis further suggests that morphometric deformities and morphologic fractures constitute distinct entities; morphologic fractures conform more closely to the expected epidemiology of OVF.

Radiographic osteoporotic vertebral fractures in elderly men: a brief review focusing on differences between the sexes.

Bone loss occurs in both sexes as a result of ageing but is exacerbated in women by the hormonal changes associated with menopause. Unlike in women, secondary osteoporosis occurs in almost half of men diagnosed with osteoporosis. Moreover, vertebral fractures (VFs) seen in elderly men may more likely be the result of high energy trauma. The osteoporotic vertebral fracture (OVF) radiograph diagnosis criteria for women may not be directly applicable for men. Particular attention should be paid to the mid-thoracic level where over-diagnosis commonly occurs. For wedge-shaped vertebral deformities (VDs) or VDs with anterior height reduction only, a diagnosis of OVF requires great caution, as they are poorly correlated to bone mineral density (BMD). For age-matched subjects, it is likely that elderly men's prevalent radiographic OVFs are approximately half of the elderly women's. This male-female ratio is very similar to other clinical fractures such as those occurring at the hip. Even so, the clinical relevance of OVF in elderly men may be less than that of elderly women. On the other hand, for elderly men with hip BMD-based osteoporosis, the OVF risk is as high as that of osteoporotic women. Elderly Chinese men have a lower OVF prevalence than age-matched Caucasian men.

Vertebral Fractures in Individuals With Type 2 Diabetes: More Than Skeletal Complications Alone.

OBJECTIVE: We aimed to assess whether individuals with type 2 diabetes (T2D) have increased risk of vertebral fractures (VFs) and to estimate nonvertebral fracture and mortality risk among individuals with both prevalent T2D and VFs. RESEARCH DESIGN AND METHODS: A systematic PubMed search was performed to identify studies that investigated the relationship between T2D and VFs. Cohorts providing individual participant data (IPD) were also included. Estimates from published summary data and IPD cohorts were pooled in a random-effects meta-analysis. Multivariate Cox regression models were used to estimate nonvertebral fracture and mortality risk among individuals with T2D and VFs. RESULTS: Across 15 studies comprising 852,705 men and women, individuals with T2D had lower risk of prevalent (odds ratio [OR] 0.84 [95% CI 0.74-0.95]; I 2 = 0.0%; P het = 0.54) but increased risk of incident VFs (OR 1.35 [95% CI 1.27-1.44]; I 2 = 0.6%; P het = 0.43). In the IPD cohorts (N = 19,820), risk of nonvertebral fractures was higher in those with both T2D and VFs compared with those without T2D or VFs (hazard ratio [HR] 2.42 [95% CI 1.86-3.15]) or with VFs (HR 1.73 [95% CI 1.32-2.27]) or T2D (HR 1.94 [95% CI 1.46-2.59]) alone. Individuals with both T2D and VFs had increased mortality compared with individuals without T2D and VFs (HR 2.11 [95% CI 1.72-2.59]) or with VFs alone (HR 1.84 [95% CI 1.49-2.28]) and borderline increased compared with individuals with T2D alone (HR 1.23 [95% CI 0.99-1.52]). CONCLUSIONS: Based on our findings, individuals with T2D should be systematically assessed for presence of VFs, and, as in individuals without T2D, their presence constitutes an indication to start osteoporosis treatment for the prevention of future fractures.

Comparative Analysis of the Radiology of Osteoporotic Vertebral Fractures in Women and Men: Cross-Sectional and Longitudinal Observations from the Canadian Multicentre Osteoporosis Study (CaMos).

We compared two methods for osteoporotic vertebral fracture (VF) assessment on lateral spine radiographs, the Genant semiquantitative (GSQ) technique and a modified algorithm-based qualitative (mABQ) approach. We evaluated 4465 women and 1771 men aged ≥50 years from the Canadian Multicentre Osteoporosis Study with available X-ray images at baseline. Observer agreement was lowest for grade 1 VFs determined by GSQ. Among physician readers, agreement was greater for VFs diagnosed by mABQ (ranging from 0.62 [95% confidence interval (CI) 0.00-1.00] to 0.88 [0.76-1.00]) than by GSQ (ranging from 0.38 [0.17-0.60] to 0.69 [0.54-0.85]). GSQ VF prevalence (16.4% [95% CI 15.4-17.4]) and incidence (10.2/1000 person-years [9.2; 11.2]) were higher than with the mABQ method (prevalence 6.7% [6.1-7.4] and incidence 6.3/1000 person-years [5.5-7.1]). Women had more prevalent and incident VFs relative to men as defined by mABQ but not as defined by GSQ. Prevalent GSQ VFs were predominantly found in the mid-thoracic spine, whereas prevalent mABQ and incident VFs by both methods co-localized to the junction of the thoracic and lumbar spine. Prevalent mABQ VFs compared with GSQ VFs were more highly associated with reduced adjusted L1 to L4 bone mineral density (BMD) (-0.065 g/cm2 [-0.087 to -0.042]), femoral neck BMD (-0.051 g/cm2 [-0.065 to -0.036]), and total hip BMD (-0.059 g/cm2 [-0.076 to -0.041]). Prevalent mABQ VFs compared with prevalent GSQ were also more highly associated with incident VF by GSQ (odds ratio [OR] = 3.3 [2.2-5.0]), incident VF by mABQ (9.0 [5.3-15.3]), and incident non-vertebral major osteoporotic fractures (1.9 [1.2-3.0]). Grade 1 mABQ VFs, but not grade 1 GSQ VFs, were associated with incident non-vertebral major osteoporotic fractures (OR = 3.0 [1.4-6.5]). We conclude that defining VF by mABQ is preferred to the use of GSQ for clinical assessments. © 2017 American Society for Bone and Mineral Research.

Recommendations for bone mineral density reporting in Canada: a shift to absolute fracture risk assessment.

In June 2005, new Canadian recommendations for bone mineral density (BMD) reporting in postmenopausal women and older men were published by Osteoporosis Canada (formerly the Osteoporosis Society of Canada) and the Canadian Association of Radiologists. The recommendations were developed by a multidisciplinary working group that included the Canadian Panel of the International Society for Clinical Densitometry and were reviewed and endorsed by multiple stakeholders. Previous Canadian osteoporosis guidelines advised intervention based on an individual's World Health Organization category (normal, osteopenia, or osteoporosis) as a marker of relative fracture risk. In the new approach, an individual's 10-yr absolute fracture risk, rather than BMD alone, is used for fracture risk categorization. Absolute fracture risk is determined using not only BMD results, but also age, sex, fragility fracture history, and glucocorticoid use. A procedure is presented for estimating absolute 10-yr fracture risk in untreated individuals, leading to assigning an individual to 1 of 3 absolute fracture risk categories: low risk (<10% 10-yr fracture risk), moderate risk (10-20%), and high risk (>20%). We propose that an individual's absolute fracture risk category should be the basis for deciding on treatment and frequency of BMD monitoring.

Precision assessment and radiation safety for dual-energy X-ray absorptiometry: position paper of the International Society for Clinical Densitometry.

Measurement of bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) is used to diagnose osteoporosis, assess the risk of fracture, and monitor changes in BMD over time. Because biological changes in BMD are usually small in proportion to the error inherent in the test itself, interpretation of serial BMD tests depends on knowledge of the smallest change in BMD that is beyond the range of error. This value, called the least significant change (LSC), varies according to the instrument used, the patient population being tested, the measurement site, the skill of the technologist at positioning the patient and analyzing the test, and the confidence interval used in the calculation. The precision and LSC values provided by the manufacturer cannot be applied to clinical bone densitometry centers because of the differences in the patients being tested and the technologist performing the test. Because harmful errors in clinical management may occur from incorrectly interpreting serial BMD tests, it is recommended that every DXA technologist conduct a precision assessment and calculate the LSC for each measurement site and DXA instrument used. Precision assessment provides direct benefit to patients by allowing clinicians to make clinical decisions based on genuine change or stability of BMD. The patient-care benefits of precision assessment outweigh the risk of exposure to trivial doses of ionizing radiation.

Ten-year incident osteoporosis-related fractures in the population-based Canadian Multicentre Osteoporosis Study - comparing site and age-specific risks in women and men.

BACKGROUND: Population-based incident fracture data aid fracture prevention and therapy decisions. Our purpose was to describe 10-year site-specific cumulative fracture incidence by sex, age at baseline, and degree of trauma with/without consideration of competing mortality in the Canadian Multicentre Osteoporosis Study adult cohort. METHODS: Incident fractures and mortality were identified by annual postal questionnaires to the participant or proxy respondent. Date, site and circumstance of fracture were gathered from structured interviews and medical records. Fracture analyses were stratified by sex and age at baseline and used both Kaplan-Meier and competing mortality methods. RESULTS: The baseline (1995-97) cohort included 6314 women and 2789 men (aged 25-84 years; mean±SD 62±12 and 59±14, respectively), with 4322 (68%) women and 1732 (62%) men followed to year-10. At least one incident fracture occurred for 930 women (14%) and 247 men (9%). Competing mortality exceeded fracture risk for men aged 65+years at baseline. Age was a strong predictor of incident fractures especially fragility fractures, with higher age gradients for women vs. men. Major osteoporotic fracture (MOF) (hip, clinical spine, forearm, humerus) accounted for 41-74% of fracture risk by sex/age strata; in women all MOF sites showed age-related increases but in men only hip was clearly age-related. The most common fractures were the forearm for women and the ribs for men. Hip fracture incidence was the highest for the 75-84 year baseline age-group with no significant difference between women 7.0% (95% CI 5.3, 8.9) and men 7.0% (95% CI 4.4, 10.3). INTERPRETATION: There are sex differences in the predominant sites and age-gradients of fracture. In older men, competing mortality exceeds cumulative fracture risk.

Standards and guidelines for performing central dual-energy x-ray absorptiometry in premenopausal women, men, and children.

The Canadian Panel of the International Society for Clinical Densitometry has developed standards in order to establish the minimum level of acceptable performance for the practice of bone densitometry in Canada. Previously, this group addressed the performance of densitometry in postmenopausal women. This report addresses the use of densitometry in men, premenopausal women, and children with a focus on dual-energy X-ray absorptiometry.

Fracture risk prediction: importance of age, BMD and spine fracture status.

Our purpose was to identify factors for a parsimonious fracture risk assessment model considering morphometric spine fracture status, femoral neck bone mineral density (BMD) and the World Health Organization (WHO) clinical risk factors. Using data from 2761 subjects from the Canadian Multicentre Osteoporosis Study (CaMos), a prospective, longitudinal cohort study of randomly selected community-dwelling men and women aged ⩾50 years, we previously reported that a logistic regression model considering age, BMD and spine fracture status provided as much predictive information as a model considering these factors plus the remaining WHO clinical risk factors. The current analysis assesses morphometric vertebral fracture and/or nonvertebral fragility fracture at 5 years using data from an additional 1964 CaMos subjects who have now completed 5 years of follow-up (total N=4725). Vertebral fractures were identified from lateral spine radiographs assessed using quantititative morphometry at baseline and end point. Nonvertebral fragility fractures were determined by questionnaire and confirmed using radiographs or medical records; fragility fracture was defined as occurring with minimal or no trauma. In this analysis, a model including age, BMD and spine fracture status provided a gradient of risk per s.d. (GR/s.d.) of 1.88 and captured most of the predictive information of a model including morphometric spine fracture status, BMD and all WHO clinical risk factors (GR/s.d. 1.92). For comparison, this model provided more information than a model considering BMD and the WHO clinical risk factors (GR/s.d. 1.74). These findings confirm the value of age, BMD and spine fracture status for predicting fracture risk.

Recognizing and reporting vertebral fractures: reducing the risk of future osteoporotic fractures.

OBJECTIVE: Given the increasing evidence that vertebral fractures are underdiagnosed and not acted on, Osteoporosis Canada and the Canadian Association of Radiologists initiated a project to develop and publish a set of recommendations to promote and facilitate the diagnosis and reporting of vertebral fractures. OPTIONS: The identification of spinal fractures is not uniform. More than 65% of vertebral fractures cause no symptoms. It is also apparent that vertebral fractures are inadequately recognized when the opportunity for diagnosis arises fortuitously. It is to patients' benefit that radiologists report vertebral fractures evident on a chest or other radiograph, no matter how incidental to the immediate clinical indication for the examination. OUTCOMES: The present recommendations can help to close the gap in care in recognizing and treating vertebral fractures, to prevent future fractures and thus reduce the burden of osteoporosis-related morbidity and mortality, as well as fracture-related costs to the health care system. EVIDENCE: Several studies indicate that a gap exists in regard to the diagnosis of vertebral fractures and the clinical response following such diagnosis. All recommendations presented here are based on consensus. VALUES: These recommendations were developed by a multidisciplinary working group under the auspices of the Scientific Advisory Council of Osteoporosis Canada and the Canadian Association of Radiologists. BENEFITS, HARM, AND COSTS: Prevalent vertebral fractures have important clinical implications in terms of future fracture risk. Recognizing and reporting fractures incidental to radiologic examinations done for other reasons has the potential to reduce health care costs by initiating further steps in osteoporosis diagnosis and appropriate therapy. RECOMMENDATIONS: Physicians should be aware of the importance of vertebral fracture diagnosis in assessing future osteoporotic fracture risk. Vertebral fractures incidental to radiologic examinations done for other reasons should be identified and reported. Vertebral fractures should be assessed from lateral spinal or chest radiographs according to the semiquantitative method of Genant and colleagues. Grade II and Grade III fractures as classified by this method should be given the greatest emphasis. Semiquantitative fracture recognition should include the recognition of changes such as loss of vertebral end-plate parallelism, cortical interruptions, and quantitative changes in the anterior, midbody, and posterior heights of vertebral bodies. When spine radiographs are performed to assess the presence of vertebral fractures, anteroposterior examinations may assist in the initial evaluation. The standard follow-up need only consist of single lateral views of the thoracic and lumbar spine that include T4 to L4 vertebrae. The radiographic technique described in this paper, or a technique of comparable efficacy, should be used. Dual X-ray absorptiometry examinations that include lateral spinal morphological assessments (vertebral fracture assessment) may contribute to fracture recognition. Educational material about the clinical importance of vertebral fracture recognition as a potential indicator of future osteoporotic fracture risk with its associated morbidity and mortality should be directed to all physicians. VALIDATION: Recommendations were based on consensus opinion.