中文摘要：

目的评价硫酸钙（CS）对骨质疏松绵羊腰椎微观结构和生物力学性能的强化效果。方法健康成年雌性绵羊8只,经双侧卵巢切除术和注射甲泼尼龙建立骨质疏松模型。建模成功后,每只绵羊的腰椎（L1-L4）均随机分为两组,CS组经椎弓根向椎体内注射CS,空白组椎体不进行任何强化。3个月后处死动物并收集腰椎（L_1-L_4）。采用microCT扫描、组织学观察和生物力学实验评价椎体的微观结构和生物力学性能。结果建模后绵羊腰椎的平均骨密度较前显著下降（下降幅度〉25%,P〈0.05）,骨质疏松模型建立成功。注射后3个月CS完全降解,未有任何残留。CS组椎体的骨质条件（骨小梁数量和密度）显著优于空白组（P〈0.05）,椎体的生物力学性能也显著高于空白组（P〈0.05）。结论局部注射CS可显著改善骨质疏松椎体的微观结构和生物力学性能,降低潜在的骨折风险。

英文摘要：

Objective To investigate the effect of calcium sulfate （CS） on improvement of microstructure and biomechanical performance of osteoporotic lumbar vertebrae in sheep. Methods Osteoporosis model was reproduced in 8 female sheep by bilateral ovariectomy and methylprednisolone administration. Then the lumbar vertebrae （L_1-L_4） in each sheep were randomly divided into CS group and blank group （2 vertebrae in each sheep）. CS was injected into the vertebral bodies through the pedicle in CS group, and no treatment was given in blank group. All of the animals were sacrificed 3 months later, and vertebrae L_1- L_4 were harvested. The microstructure and biomechanical performance of vertebral bodies were assessed by micro-CT scanning, histological observation and biomechanical test. Results After ovariectomy and methylprednisolone administration, the mean bone mineral density of the lumbar vertebrae in the sheep was significantly decreased （〉25%） compared with that before induction （P〈0.05）, demonstrating a successful reproduction of osteoporosis model. Three months after injection, it was shown that CS was completely degraded without any remnant in the bone tissue. The quality of the bone tissue （trabecular number and tissue mineral density） in CS group was significantly better than that in blank group （P〈0.05）, and the biomechanical performance in CS group was significantly superior to that in blank group （P〈0.05）. Conclusions Local injection of CS could significantly improve the microstructure and biomechanical performance of osteoporotic vertebrae, and it may decrease the risk of fracture of patients with osteoporosis.