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目的 为探讨和评估外周定量CT(pQCT)在骨组织结构和力学特性测量中的价值。方法 将 5 0只 4月龄雌性未交配的健康Wistar大鼠 ,经适应性喂养 8周后 ,随机分成 6组 ,其中 1组处死作为基线组 (Base ,n =8) ,其余大鼠行去卵巢手术 (Ovariectomy ,OVX)或假手术 (Sham)。OVX组共16只 ,Sham组共 8只 ,雌激素干预组 (O +E)共 18只。处死时留取右侧胫骨和股骨分别进行骨组织形态计量学分析、pQCT测量、股骨远端凹入实验和股骨中段三点弯曲试验。结果 大鼠经OVX后胫骨近端骨小梁体积显著降低 (8 1%± 1 4 %比 19 5 %± 1 5 % ,OVX比Sham ,P <0 0 1)和pQCT检查股骨远段的小梁骨骨矿含量 (1 7± 0 3比 3 2± 0 5mg/mm ,OVX比Sham ,P <0 0 1) ,骨矿盐密度(TrabBMD ,15 8± 32比 32 0± 39mg/mm3 ,OVX比ShamP <0 0 1)显著减少 ,同时松质骨的力学特性下降 ,最大载荷和刚度均显著低于假手术组。经雌激素干预后以上各指标均得以改善。皮质骨骨量和结构主要表现为增龄性的改变 ,OVX和雌激素干预对其影响不明显 ,相关分析表明pQCT测得的股骨远端骨密度和组织计量学指标骨小梁的体积和数目呈显著正相关 (r分别为 0 88和 0 73,P <0 0 1) ,股骨松质骨骨量和骨密度与凹入实验的最大载荷和刚度也呈显著正相关 (r为 0
Objective To investigate and evaluate the value of peripheral quantitative CT (pQCT) in the measurement of bone structure and mechanical properties. Methods Fifty healthy 4-month-old unwed female Wistar rats were randomly divided into 6 groups after adaptive feeding for 8 weeks. One group was sacrificed as baseline group (Base, n = 8) Ovariectomy (OVX) or sham. 16 in OVX group, 8 in Sham group and 18 in O + E group. At the time of sacrifice, the right tibia and femur were taken for bone histomorphometry, pQCT measurement, distal femur intima and three-point bending test of femur. Results The volume of trabecular bone in the proximal tibia decreased significantly after OVX in rats (8 1% ± 14% vs 19 5% ± 15%, OVX vs Sham, P 0 01) and pQCT Bone mineral content (17 ± 0 3 vs 32 ± 0 5 mg / mm, OVX vs Sham, P 0 01), bone mineral density (Trab BMD, 15 8 ± 32 vs 32 0 ± 39 mg / mm 3, OVX was significantly lower than that of ShamP <0 01). At the same time, the mechanical properties of cancellous bone decreased and the maximum load and stiffness were significantly lower than those of sham operation group. After estrogen intervention, the above indexes are all improved. Cortical bone mass and structure mainly for age-related changes, OVX and estrogen intervention had no significant effect on it, the correlation analysis showed that pQCT measured distal femur bone mineral density and histomorphometry trabecular volume and number (R = 0 88 and 0 73 respectively, P <0.01). The femoral cancellous bone mass and bone mineral density also showed a significant positive correlation with the maximum load and stiffness of the concave test (r = 0