Title of article :
Effect of ovariectomy and calcium deficiency on the ultrasound velocity, mineral density and strength in the rat femur
Author/Authors :
S. M. Han، نويسنده , , T. E. Szarzanowicz، نويسنده , , I. Ziv، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 1998
Abstract :
Objective. Ultrasound transmission velocity (UTV) and bone mineral density (BMD) were examined as possible predictors of the bending strength of osteoporotic long bones in ovariectomized rats treated with calcium-depleted diet.
Background. Changes in cancellous bone quality due to osteoporosis have been well documented, but only a few studies described non-invasive assessment of the biomechanical quality of long bones.
Methods. Forty-three rats were divided into three groups: ovariectomized and calcium-depleted diet, ovariectomized and standard diet, and untreated controls. All femora were scanned by quantitative computed tomography (QCT) to measure BMD and cortical dimensions at the mid-diaphysis. Bending strength was determined from the maximum bending moment and the femoral cortical dimensions at the mid-diaphysis. The UTV of cortical bond at the mid-disphysis of the femur was measured in the proximal/distal direction.
Results. It was found that bending strength was significantly different among the groups (p < 0.0001). Despite the fact that bending strength of the osteoporotic rat femur significantly decreased, the osteoporotic effect did not produce a significant change in cortical thickness. UTV in the ovariectomized and calcium-depleted diet was lower than in the other groups; however, no significant differences were found betwene those on the standard diet and the untreated controls. The BMD in ovariectomized rats was also significantly lower than in the untreated controls (p < 0.05); however, the BMD in those fed with the calcium-depleted diet was not significantly different from those with the standard diet. Both cortical UTV and BMD as a single variable may not predict changes in bending strength of the cortical bone at the mid-diaphysis of the rat femur. However, the combined effect of UTV and BMD was significantly better than a single parameter in the assessment of strength.
Keywords :
Osteoporosis , ultrasound transmission velocity , Rat femur , ovariectomy , Bone strength , bone mineral density , calcium-depleted diet
Journal title :
Clinical Biomechanics
Journal title :
Clinical Biomechanics