Je. Zerwekh et al., REFLECTION ULTRASOUND VELOCITIES AND HISTOMORPHOMETRIC AND CONNECTIVITY ANALYSES - CORRELATIONS AND EFFECT OF SLOW-RELEASE SODIUM-FLUORIDE, Journal of bone and mineral research, 12(12), 1997, pp. 2068-2075
To better understand how structural and functional bone properties con
tribute to the changes in bone biomechanical properties revealed by ul
trasound critical angle reflectometry (UCR) analysis, we measured both
UCR velocities and histomorphometric properties in bone biopsy specim
ens from 33 osteoporotic patients before and following intermittent sl
ow-release sodium fluoride (SRNaF) and continuous calcium citrate admi
nistration, Mean skeletal fluoride exposure was 17 months, and mean sk
eletal fluoride content was 0.203 +/- 0.088 SD% bone ash, Intermittent
SRNaF and continuous calcium citrate promoted significant increases i
n trabecular thickness (122 +/- 18 SD mu m to 131 +/- 20, p = 0.020),
mineral apposition rate (0.79 +/- 0.26 to 1.05 +/- 0.40 mu m/day,p = 0
.014), and a significant decline in eroded surface (3.9 +/- 1.6 to 2.8
+/- 1.4%, p = 0.002). There were also significant increases in node n
umber (0.193 +/- 0.100 to 0.368 +/- 0.245, p < 0.01) and node-to-node
strut length (0.076 +/- 0.087 to 0.191 +/- 0.173, p < 0.01) relative t
o total cancellous area, Cortical UCR velocity did not change but canc
ellous velocity significantly increased by 97 m/s following therapy (p
= 0.0005), When compared against the significant changes in bone hist
omorphometry and connectivity, the sum of both cancellous and cortical
ultrasound velocities was significantly correlated with node number/a
rea (R-2 = 0.305, p < 0.0001) and node-to-node strut length/area (R-2
0.372, p < 0.0001) and to a lesser extent with mineral apposition rate
(R-2 = 0.106, p = 0.032), Multiple regression analysis demonstrated t
hat 40% of the variance in the sum of the UCR velocities can be accoun
ted for by the variability in these histomorphometric and connectivity
parameters, There were no significant correlations between the sum of
cortical and cancellous ultrasound velocities and cancellous bone vol
ume (R-2 = 0.014 p 0.533), trabecular thickness (R-2 = 0.012, p = 0.47
), or bone mineral density (R-2 = 0.003, p = 0.80). These observations
indicate that velocity measurements with the UCR methodology show an
improvement in bone elasticity associated, in part, with an improvemen
t in the rate of bone mineralization and an improvement in bone qualit
y at the structural level as shown by microarchitecture.