In 1951, Ardran reported that metastatic bone lesions could be detectable on plain radiography with 30% to 50% of decalcification. Authors performed experimental study for minimum level of decalcification to detect the osteolytic bone metastasis of long bone with recent technique of radiographs.
One pair of fibula and humerus from two cadavers was cut into specimen 1 inch in length. Distal half of specimen was dipped into hydrochloride (HCl) with 15 min interval. All 16 specimens were checked by film-type radiography (FR), computed radiography (CR), digital radiography (DR). To exclude inter-observer's variance, 3 radiologists evaluated images. Calcium amount before and after decalcification was measured and expressed in percentage of decalcification.
Osteolytic changes were detectable with 11% to 16% of decalcification for fibula and 3% to 8% for humerus on plain radiography with FR, CR, and DR.
Our study showed that minimum of 3% and maximum of 16% of decalcification is necessary when osteolytic metastatic bone lesions of long bone could be detected on plain radiography.
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To retrospectively assess whether the response of subtrochanteric lateral cortex (STLC) is different according to the bisphosphonate agents in terms of bone mineral density (BMD) change.
A total of 149 subjects, who had 2- to 4-year interval follow-up of BMD using dual energy X-ray absorptiometry (DXA), were included in this retrospective study divided into following 3 groups: control group (no consumption of any anti-osteoporotic drugs, n=38), alendronate group (naïve alendronate users, n=48), risedronate group (naïve risedronate users, n=63). BMD was measured at the STLC and subtrochanteric medial cortex (STMC) in each patient by drawing rectangular ROIs at the bone cortices. The percent change of BMD at the STLC were compared between the aforementioned 3 groups by using analysis of covariance model to control five independent variables of age, body mass index, percent change of STMC, hip axis length, time interval between DXA examinations.
The least square mean values±standard deviation of the percent change of BMD in the control, alendronate, and risedronate groups were 1.46±1.50, 2.23±1.26, and 6.96±1.11, respectively. The risedronate group showed significantly higher change of BMD percentage compared with the control (adjusted
The percent change of BMD at the STLC in the risedronate user group was greater than the alendronate and control groups. The implication of these changes needs to be further verified.
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Bone mineral density (BMD) is an important index in diagnosis of osteoporosis and other metabolic bone diseases, prediction of fractures, and monitoring treatment. This study was to find a more feasible technique for prediction of osteoporotic fracture between dual energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT) and to reveal the actual change of bone strength when BMD was changed.
Ten of these 20 specimens were used as the demineralized group and the other 10 as the control. Each specimen was immersed in HCl solution at for a period of at least 10 minutes, up to 100 minutes, at an interval of 10 minutes for different levels of demineralization. BMD was measured using DXA and QCT. Uniaxial compression tests were conducted to measure biomechanical parameters. Pearson correlation analysis was used respectively between BMD and biomechanical parameters and between DXA and QCT.
Elastic modulus (r=0.87) and yield stress (r=0.84) showed a statistically significant correlation with DXA BMD. Through correlation analysis with QCT BMD and elastic modulus, correlation coefficient showed hemi-vertebra (r=0.80) and trabecular (r=0.68). In yield stress, there was a statistically significant correlation in hemi-vertebra (r=0.87) and trabecular bone (r=0.84).
DXA is a current standard technique not only for diagnosis of osteoporosis but also for prediction of fracture risk compared to QCT. Actual decrease of bone strength was much greater than that of BMD by both DXA and QCT.
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