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 μm 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). This finding supports the suggestion that the strength of whole vertebrae (structure) could also have been increased following treatment as a result of a rise in bone mass, possibly from an increased number of trabeculae. Taken together the results support the possibility that intermittent slow‐release sodium fluoride treatment in combination with calcium citrate can enhance the strength of whole bone (spine) by improving the microscopic or material property of bone, as well as by increasing bone mass.
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Orthopedics and Sports Medicine