Automated opportunistic osteoporotic fracture risk assessment using computed tomography scans to aid in FRAX underutilization

The purpose of this study was to evaluate the utility of lumbar spine attenuation measurement for bone mineral density (BMD) assessment at screening computed tomographic colonography (CTC) using central dual-energy X-ray absorptiometry (DXA) as the reference standard. Two-hundred and fifty-two adults (240 women and 12 men; mean age 58.9 years) underwent CTC screening and central DXA BMD measurement within 2 months (mean interval 25.0 days). The lowest DXA T-score between the spine and hip served as the reference standard, with low BMD defined per World Health Organization as osteoporosis (DXA T-score ≤ -2.5) or osteopenia (DXA T-score between -1.0 and -2.4). Both phantomless quantitative computed tomography (QCT) and simple nonangled region-of-interest (ROI) multi-detector CT (MDCT) attenuation measurements were applied to the T(12) -L(5) levels. The ability to predict osteoporosis and low BMD (osteoporosis or osteopenia) by DXA was assessed. A BMD cut-off of 90 mg/mL at phantomless QCT yielded 100% sensitivity for osteoporosis (29 of 29) and a specificity of 63.8% (143 of 224); 87.2% (96 of 110) below this threshold had low BMD and 49.6% (69 of 139) above this threshold had normal BMD at DXA. At L(1) , a trabecular ROI attenuation cut-off of 160 HU was 100% sensitive for osteoporosis (29 of 29), with a specificity of 46.4% (104 of 224); 83.9% (125 of 149) below this threshold had low BMD and 57.5% (59/103) above had normal BMD at DXA. ROI performance was similar at all individual T(12) -L(5) levels. At ROC analysis, AUC for osteoporosis was 0.888 for phantomless QCT [95% confidence interval (CI) 0.780-0.946] and ranged from 0.825 to 0.853 using trabecular ROIs at single lumbar levels (0.864; 95% CI 0.752-0.930 at multivariate analysis). Supine-prone reproducibility was better with the simple ROI method compared with QCT. It is concluded that both phantomless QCT and simple ROI attenuation measurements of the lumbar spine are effective for BMD screening at CTC with high sensitivity for osteoporosis, as defined by the DXA T-score. Copyright © 2011 American Society for Bone and Mineral Research.

A fracture liaison service model of care is widely recommended and applied, but data on its effectiveness are scarce. Therefore, the risk of subsequent nonvertebral fractures and mortality within two years after a nonvertebral fracture was analyzed in patients who presented to a hospital with a fracture liaison service and a hospital without a fracture liaison service. In 2005 to 2006, all consecutive patients with an age of fifty years or older presenting with a nonvertebral fracture were included. In the group that presented to a hospital without a fracture liaison service (the no-FLS group), only standard fracture care procedures were followed to address proper fracture-healing. In the group that presented to a hospital with a fracture liaison service (the FLS group), dual x-ray absorptiometry scans and laboratory testing were performed, and if applicable, patients were treated according to the Dutch guideline for osteoporosis. The risk for subsequent nonvertebral fracture and mortality were analyzed using multivariable Cox regression models with adjustments for age, sex, and baseline fracture location. In total, 1412 patients presented to the fracture liaison service (73.2% were women, and the mean age was 71.1 years), and 1910 underwent standard fracture care (69.8% were women, and the mean age was 69.5 years). After adjustment for age, sex, and baseline fracture location, patients who attended the fracture liaison service had a significantly lower mortality risk (hazard ratio: 0.65; 95% confidence interval [CI]: 0.53 to 0.79) over two years of follow-up. The subsequent nonvertebral fracture risk was also significantly lower in the patients in the FLS group, but this effect was time-dependent, with a hazard ratio of 0.84 (95% CI: 0.64 to 1.10) at twelve months and 0.44 (95% CI: 0.25 to 0.79) at twenty-four months. Patients seen at the fracture liaison service had a significantly lower mortality and subsequently a lower risk of nonvertebral fracture than those not seen at the fracture liaison service, with a reduction of 35% and 56%, respectively, over two years of follow-up. A fracture liaison service appears to be a successful approach to reduce the number of subsequent fractures and premature mortality in this cohort of patients.