Search

It has been suggested that fluoride therapy, while increasing bone mass, produces bone with inferior mechanical properties. In the present report this hypothesis was tested using a novel reflection ultrasound technique. Transiliac crest bone biopsies were obtained from 16 patients with osteoporosis and vertebral compression fractures (12 women and 4 men, mean age 56 years) before and after approximately 2 years of intermittent slow-release sodium fluoride therapy (25 mg twice a day) combined with continuous calcium citrate supplementation. Samples were analyzed by a reflection ultrasound method, which analyzes ultrasound velocity with a sample site resolution of 200 microns and thus provides a measure of the mechanical property of single trabeculae (material). For the group, mean fractional change in velocity increased 6.1 +/- 2.3% (SEM) from a mean value of 3303 +/- 80 to 3484 +/- 55 m/s (p = 0.028). A total of 13 patients (81%) demonstrated higher velocities after treatment. Thus reflection ultrasound analysis of bone appears to provide a sensitive means of assessing changes in the material property of bone. Furthermore, these results suggest that the treatment regimen utilized in these patients improves strength of bone at the material or trabecular level largely independently of change in bone mass. The combination therapy also increased spinal (L2-L4) bone density for the group as assessed by dual-photon absorptiometry (5.3 +/- 2.0%). There was no significant correlation between the change in ultrasound velocity and bone density (r = 0.0026, p = 0.996).(ABSTRACT TRUNCATED AT 250 WORDS)

Osteoporosis is a disease characterized by a reduction in bone density which predisposes to fracture after even minimal trauma. Fluoride, because it has consistently been shown to stimulate bone formation and increase trabecular bone density, has been widely studied for the treatment of osteoporosis. The article focuses on the dose response, duration of treatment, and skeletal sites of action of fluoride; we also include comments on the effect of fluoride on vertebral and appendicular fracture rates. The skeletal response to fluoride doses, ranging from 15 to 43 mg elemental fluoride per day, included a linear increase in spinal bone density at an average rate of 1.25 +/- 0.91 mg/cm3 per month. The rate of increase in spinal bone density was related to the dose of fluoride (r = 0.34, P less than 0.03). Spinal bone density had increased above the fracture threshold in 44% of patients treated with fluoride for 32 +/- 10 months. The time required to achieve this goal was, however, influenced by the pretreatment spinal bone density and interpatient variation in response to fluoride treatment. Patients whose spinal bone density remained below the fracture threshold had lower pretreatment bone densities and/or slower rates of increase in spinal bone density (P less than 0.001). The osteogenic effect of fluoride was not limited to the spine. After 2 years of fluoride therapy, we found bone density in the femoral condyle (measured by QCT) to have increased by 13 +/- 2.6 mg/cm3 (n = 38, P less than 0.001); bone density in the hip (measured by DPA) was increased by 0.0261 +/- 0.015 g/cm2 (n = 55, P less than 0.025).(ABSTRACT TRUNCATED AT 250 WORDS)

Measurements of the combined cortical thickness at the midshafts of the second metacarpal and the proximal radius, as well as their sums, were made from fine-grained radiographs in 107 normal premenopausal and 227 postmenopausal women and in 57 women with at least two spontaneous vertebral compressions. The -2 SD level of the premenopausal women was found to be an excellent vertebral fracture threshold for the radius measuring site and for the sums of metacarpal and radial measurements. Only 2 of 57 (4%) and 3 of 57 (5%), respectively, of values in the vertebral compression group fell at or above this level. At -3 SD a "secondary fracture threshold" was found for the sums in that only 7 of 57 (12%) of values in women with vertebral compressions were above this limit, but -3 SD was less satisfactory for the radius. We conclude that this method discriminates as well between nonfracture and fracture cases as other radiologic methods for measurement of bone mass or density. Because it is less costly it seems better suited for mass screening in selecting postmenopausal women for preventive therapy than the less widely available high-technology methods.

Estrogen cannot replace bone that has been lost nor...straighten curvature of the spine or restore lost height. Usually, however, it can arrest the disease's progression.

The aim of this study was to assess the performance of a new bone densitometry technique, X-ray absorptiometry, in vertebral osteoporosis with fracture(s). Vertebral and femoral (neck, Ward's triangle and trochanter) bone density was measured in 60 women with at least one vertebral compression fracture of osteoporotic origin (mean age: 61), 100 controls of the same age and in 40 young adults (mean age: 30). Osteoporosis patients had significantly (p less than 0.0005) low bone density values in comparison with the young adults: -40 to -50% (T-score -1.9 to -2.3) for the femur and with control subjects of the same age: -20 to -30% (Z-score -2.2 to -2.6) for the spine; -10 to -20 (Z-score -1.1 to -1.3) for the femur. Measurements using the spine and Ward's triangle had the best discriminant values assessed by the ROC (Receiver Operating Characteristics) technique (areas under the curve: 95% and 84% respectively). The fracture threshold was fixed at a vertebral bone density of 0.78 g/cm2, this value giving the best compromise between sensitivity (83%) and specificity (95%) with 91% of subjects appropriately classified. Reproducibility was assessed in the short term in 9 osteoporosis patients. The mean standard deviation of measurements was 0.017 g/cm2 (coefficient of variation: 2.6%) as compared with 0.010 g/cm2 (coefficient of variation: 0.8%) in the young adult. These results emphasise the true advance represented by X-ray absorptiometry in the area of bone densitometry, notably in the assessment and monitoring of demineralisation disorders.