[Histological observations of hydroxyapatite thermal decomposition product injected into the femur of ovariectomized rats].
Hydroxyapatite thermal decomposition product is a mixture of alpha-tricalcium phosphate and tetracalcium phosphate, which is hardened by mixing with water in vitro. This decomposition product mixed with water solution (HAp cement) was injected into the femur of 24 Wistar strain rats at 36 weeks after ovariectomy at 8 weeks of age. Age-matched rats were used as a control. The diaphysis of the femur was observed histologically at 4, 8 and 12 weeks after injection. At 4 weeks after the injection, new bone formation was seen only around the HAp cement in the control group, while new bone formation was observed in direct contact with the HAp cement in both the ovariectomized and the control groups after 8 weeks. In histomorphometrical analysis, the area of new bone bonded to the HAp cement and the ratio of the length of the HAp cement-bone interface to the circumference of the HAp cement increased with time in both groups. However the area and the ratio were significantly smaller in the ovariectomized group than in the control group.
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Department of Orthopedic Surgery, Yokohama City University School of Medicine, Kanagawa.
D000818:Animals; D001672:Biocompatible Materials; D001843:Bone Cements; D001846:Bone Development / Q000502:physiology*; D002130:Calcium Phosphates; D004195:Disease Models, Animal; D017886:Durapatite; D005260:Female; D005269:Femur; D006358:Hot Temperature; D006801:Humans; D015663:Osteoporosis, Postmenopausal / Q000503:physiopathology; D010052:Ovariectomy; D051381:Rats; D017208:Rats, Wistar
D001672:Biocompatible Materials; D001843:Bone Cements; D002130:Calcium Phosphates; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C485838:calcium phosphate, monobasic, anhydrous; D017886:Durapatite; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous