Vertebral Fracture Definition from Population-Based Data: Preliminary Results from the Canadian Multicenter Osteoporosis Study (CaMos)

Abstract

The Canadian Multicenter Osteoporosis Study is a large population-based prospective study of osteoporosis in the Canadian population. The study involves 9424 subjects, both male and female, from nine centers and seven regions of Canada. Each subject completed an extensive interview to obtain medical, demographic and lifestyle information, and was examined by dual-energy X-ray absorptiometry of the spine and hip, ultrasound of the heel and, for subjects over 50 years of age, lateral spine radiographs. Spinal morphometry of the initial radiographs was performed to determine the prevalence of vertebral deformity. A method is utilized to extract reference norms for vertebral shape from a subset of the population data, which is then used to categorize any deformity within the whole data set. Using 3 standard deviations (SD) as a limit of normality', the male prevalence of 21.5% was similar to the female prevalence of 23.5%. Using 4 SD this reduced to 7.3% and 9.3% respectively. The younger men (50-59 years) showed a higher prevalence of deformity than the women and a lower increase of prevalence with age. In the older age group (over 80 years) the female prevalence of 45% compared with 36% for the men using 3 SD (grade 1) to define the limit of normality. The female group presented with more severe deformities on average than the male group. This continuing study will provide longitudinal information regarding the development of osteoporosis and associated risk factors which will eventually be of use to develop public health policies.

Observer agreement in pediatric semiquantitative vertebral fracture diagnosis

“…Normal height ratios have been extensively assessed in adults and there is a very low likelihood of any of them exceeding the 20% height ratio reduction threshold used to define fracture [35,36]. The one anatomical area where there is a low rate of vertebrae exceeding this ratio is the mid-thoracic spine, where some anterior wedging is normally present that produces the natural thoracic kyphosis, leading to some false positives in this region of the spine using the GSQ method [31,35,36]. The rate of false positives is sufficiently low that the GSQ threshold of 20% is applied throughout the spine, including the mid-thoracic region, in clinical practice recommendations [13][14][15].…”

Geographic variation of bone mineral density and selected risk factors for prediction of incident fracture among Canadians 50 and older

“…Participants underwent a baseline clinical assessment that included measurement of height, weight, bone mineral density (BMD), and for those older that 50, a lateral lumbar and thoracic spine X-rays. Vertebral deformities were assessed from X-rays by a trained technologist using vertebral morphometry [13]. Follow-up of participants was done irrespective of any information gathered at baseline.…”

Effectiveness of antiresorptives for the prevention of nonvertebral low-trauma fractures in a population-based cohort of women

“…Controls were members of the cohort, who at the given time had not had an incident lowtrauma nonvertebral fracture after cohort entry, and who were matched with regard to time in study, age in years, baseline clinical diagnosis of osteoporosis or BMD T-score less than or equal to −2.5, baseline prevalent vertebral deformity (at least grade 2), baseline prevalent low-trauma fracture, and availability of baseline BMD [14]. If available, up to three controls were randomly selected per case.…”