可注射硫酸钙/羟基磷灰石复合物作为经皮椎体成形术填充物的实验研究

目的探讨椎体成形术的有效填充材料。方法采用PVP技术将40%可注射硫酸钙/羟基磷灰石(CSH/HA)复合物注入实验兔L6椎体内,L5椎体作为对照,于术后2、4、6、8、10、12周行影像学、组织学观察及骨组织计量学测定。结果影像学显示:术后4周实验椎体填充区密度明显高于周围松质骨密度,术后10～12周实验椎体填充区密度与周围松质骨一致。不脱钙骨组织学检查显示:术后4周复合物降解不明显,已出现成骨效应,6周实验椎体填充区内材料明显降解及出现新生骨小梁,8周实验椎体缺损边缘和中心部分的骨小梁逐渐成熟,10～12周椎体缺损已完全修复,为成熟的骨小梁组织所填充。骨组织计量学测定显示:术后10～12周实验椎体填充区骨小梁百分比及厚度与周围松质骨无显著差异。结论40%CSH/HA复合物在实验动物椎体内降解时间合适,成骨效应良好,新骨形成质量好,能有效修复椎体缺损,因而可能是一种理想的PVP填充物。     

绝经后骨质疏松症模型体视学测量和机理初探

目的:观测去势术后大鼠骨组织体视学的改变,复制绝经后骨质疏松症的动物模型,初步探讨骨质疏松症的发病机制。方法:将31只3月龄雌性SD大鼠随机分为卵巢切除术组(OVX)和假手术组(sham),术后28d和56d分别处死。测量子宫湿重,骨矿物密度(BMD)和骨组织形态计量参数,分析骨组织微结构的变化。结果:OVX组术后28d和56d大鼠子宫湿重和股骨远端1/3处骨密度均显著少于sham组(P＜0.05);OVX组股骨远端和胫骨近端的干骺端骨小梁面积百分率显著少于sham组(P＜0.01)。结论:卵巢切除术后大鼠股骨远端骨矿物密度和骨组织形态计量学参数稳步下降,胫骨近端骨矿物密度和骨组织形态计量学参数迅速下降而且不稳定;雌激素减少导致的骨质疏松主要发生在长骨的干骺端,骨骺受影响较少;骨组织形态计量参数中骨小梁面积百分比敏感性和稳定性较高。     

强骨康疏胶囊对去卵巢骨质疏松大鼠骨细微结构及骨代谢的影响

目的:观察强骨康疏胶囊对去卵巢骨质疏松大鼠的骨密度、OPG及RANKL蛋白表达、骨组织形态计量学参数及骨组织细微结构的影响。方法:制备去卵巢骨质疏松大鼠模型后,分组:正常对照组、模型空白组、中药低剂量预防组、中药高剂量预防组、雌激素预防组。给药1月后,检测各组股骨骨密度值,显微镜下观察股骨骨小梁的结构变化,并检测骨组织形态计量学参数。采用免疫组织化学染色法检测大鼠股骨OPG及RANKL蛋白表达。结果:模型空白组大鼠股骨骨密度减少,骨小梁厚度、面积、面积百分数均减少,骨小梁间距增大,股骨OPG蛋白平均光密度值显著降低,RANKL蛋白平均光密度值明显增高;雌激素预防组、中药低剂量组、中药高剂量组对上述指标均有明显改善。结论:强骨康疏胶囊能有效提高骨量,维持骨小梁立体空间结构,改善大鼠股骨远端松质骨的显微结构,能够提高骨OPG蛋白表达及抑制RANKL蛋白表达。     

注射型可吸收聚氨基酸/硫酸钙复合材料动物体内降解吸收及促成骨作用*

背景：注射型人工骨可经皮穿刺注射植入体内,对机体创伤较小,同时该型材料可以任意塑形,能较好地充填骨缺损,但目前临床上尚无在体内能完全降解吸收且具有较好促成骨作用的注射型人工骨产品。 目的：评估注射型可吸收聚氨基酸/硫酸钙复合材料(硫酸钙含量70%)动物体内的降解吸收及促成骨作用,观察其修复骨缺损的能力。 方法：取48只新西兰大白兔,在股骨外髁处制备直径为5 mm、深10 mm的骨缺损模型,以随机数字表法分为实验组和对照组,实验组将注射型可吸收聚氨基酸/硫酸钙复合材料植入骨缺损处,对照组未予干预。 结果与结论：X射线平片示：实验组骨缺损逐渐被骨痂填充,术后16周,骨缺损处恢复正常松质骨密度,塑形完成;对照组骨缺损处修复不明显。组织学检查(苏木精-伊红、MASSON染色)示：术后4周,材料开始降解,新生原始骨小梁长入材料内;术后12周,编织骨开始转化为板层骨;术后16周,材料完全被降解吸收,新生骨组织完全修复骨缺损。结果显示注射型聚氨基酸/硫酸钙复合材料在动物内能够完全降解、吸收,具备一定的成骨活性,可望用作骨修复材料。     

局部注射辛伐他汀对骨质疏松大鼠股骨髁骨小梁的改建效应

背景：局部注射具有成骨作用的辛伐他汀,可显著增加骨质疏松大鼠股骨颈及股骨髁部的骨密度及力学强度,分析局部注射辛伐他汀对股骨髁骨小梁的影响。 目的：进一步研究骨质疏松大鼠股骨内局部注射辛伐他汀对股骨髁骨小梁的影响。为将辛伐他汀应用于临床骨质疏松局部治疗提供实验基础。 方法：18只雌性SD大鼠双侧卵巢切除后3个月,制备大鼠骨质疏松模型。实验大鼠随机数字表法均分为3组,分别在实验大鼠的右侧股骨髓腔内单次注射辛伐他汀溶液5 mg、10 mg,对照组单纯注射空白载体。分别在注射后1个月处死大鼠并取材。Micro-CT扫描并定量分析骨组织形态变化。 结果与结论：给药后1个月,Micro-CT扫描结果显示,辛伐他汀治疗组的骨微结构参数如骨皮质厚度、骨小梁密度及连接率明显优于对照组。说明疏松骨骼单次注射小剂量辛伐他汀可显著促进股骨髁部骨小梁改建,改善骨骼微结构,可为强化局部、防治骨质疏松骨折的新选择进一步提供实验基础。     

去卵巢大鼠骨组织的变化

目的:观察去卵巢对大鼠骨组织的改变,以建立妇女绝经后骨质疏松的动物模型。方法:选用3月龄SD雌性大鼠16只,随机分为对照组和去卵巢组。去卵巢组大鼠的双侧卵巢被切除,对照组做假手术,持续90天。用骨矿测定仪测量大鼠股骨的骨密度及在半自动图像分析仪观测胫骨近端骨小梁的静、动态指标,并在扫描电镜下观察大鼠股骨松质骨结构的改变。结果:与对照正常组比较,去卵巢组大鼠股骨的远端的骨密度降低(P<0.05)。胫骨骨小梁的面积减少,骨小梁间隙增大。股骨的骨小梁变少,变细,断裂,连接不紧密,表面常见骨吸收形成的陷窝。结论:用切除卵巢的方法造成雌激素缺乏,导致骨质疏松,作为研究因绝经引起的原发性骨质疏松的可靠动物模型。     

大鼠胫骨骨折固定术后同侧股骨骨密度和生物力学性能的变化

目的探讨胫骨骨折后大鼠股骨骨密度及股骨生物力学性能变化及其与胫骨骨折愈合状况的关系。方法将40只3月龄雌性SD大鼠随机分为2组:手术组和对照组,每组20只。手术组实行右侧胫骨中段骨折内固定术。手术前和实行手术后第2、4、6、8、10、12周测量右侧股骨骨密度,第6周和第12周分别处死10只手术组和10只对照组大鼠,进行右侧胫骨和股骨生物力学性能的测量。结果术后6周,胫骨骨折的放射学愈合率为50%,机械愈合率为70%;术后12周胫骨骨折的放射学和机械愈合率均为100%。手术组股骨骨密度与对照组相比,术后2、4、6、8周降低(P<0.05),术后10、12周时与对照组差异无统计学意义。术后6周右侧胫骨和股骨的生物力学性能明显低于术后12周(P<0.05)。相关分析显示胫骨愈合情况与力学性能高度相关(P<0.01),胫骨力学性能与股骨骨密度和股骨力学性能高度相关(P<0.001)。结论胫骨骨折早期同侧股骨骨密度及生物力学性能下降,发生了废用性骨质疏松;但晚期随胫骨骨折愈合,股骨的骨密度和生物力学性能恢复正常。     

去卵巢大鼠骨组织的变化

目的：观察去卵巢对大鼠骨组织的改变，以建立妇女绝经后骨质疏松的动物模型。方法：选用３月龄ＳＤ雌性大鼠１６只，随机分为对照组和去卵巢组。去卵巢组的大鼠的双侧卵巢被切除，对照组做假手术，持续９０天。用骨矿测定仪测量大鼠股骨的骨密度及在半自动图像分析仪观测胫骨近端骨小梁的静、动态指标，并在扫描电镜下观察大鼠股骨松质骨结构的改变。结果：与对照组比较，去卵巢组大鼠股骨远端的骨密度明显降低。胫骨骨小梁的面积减     

去卵巢大鼠骨组织的变化

目的:观察去卵巢对大鼠骨组织的改变,以建立妇女绝经后骨质疏松的动物模型。方法:选用3月龄SD雌性大鼠16只,随机分为对照组和去卵巢组。去卵巢组的大鼠的双侧卵巢被切除,对照组做假手术,持续90天。用骨矿测定仪测量大鼠股骨的骨密度及在半自动图像分析仪观测胫骨近端骨小梁的静、动态指标,并在扫描电镜下观察大鼠股骨松质骨结构的改变。结果:与对照组比较,去卵巢组大鼠股骨远端的骨密度明显降低。胫骨骨小梁的面积减少,骨小梁间隙增加。股骨的骨小梁减少,变细,断裂,连接不紧密,表面常见骨吸收形成的陷窝。结论:用切除卵巢的方法造成雌激素缺乏,导致骨质疏松,是研究因绝经引起原发性骨质疏松的可靠动物模型。     

含肝细胞生长因子水凝胶修复家兔股骨颈部缺损

背景:肝细胞生长因子可促进骨组织再生,在骨组织修复方面有着巨大的潜力,但是在体内较短的半衰期限制了其在临床的应用。目的:观察含有肝细胞生长因子的半合成细胞外基质样水凝胶体内促进股骨颈骨缺损修复的作用。方法:取12只兔制作双侧股骨颈骨缺损模型,采用自体配对对比,左侧为对照侧不对骨缺损做任何处置,右侧为实验侧植入含有肝细胞生长因子的半合成细胞外基质样水凝胶。结果与结论:苏木精-伊红染色见2周时实验侧缺损修复区血管分布较对照侧均匀;4周时实验侧缺损区均匀填充新生骨小梁,而对照侧由外向内骨小梁形成减少;8周时实验侧缺损区皮质骨形成,并且骨髓腔再通,有骨髓细胞填充,对照侧仍有粗大骨痂填充缺损区,堵塞髓腔。钼靶X射线观测到8周时,实验侧难以区分正常骨质与新生骨质交界线,而对照侧缺损区与周围骨质分界明显。证实含有肝细胞生长因子的半合成细胞外基质样水凝胶可以促进家兔股骨颈部骨缺损的骨组织修复。     

bBMP异位诱导成骨的Micro—CT评价

借助Micro—CT评价单纯牛骨形态发生蛋白（bovine bone morphogenetic protein,bBMP）异位诱导成骨的长期三维影像学及骨质变化。（20±2）g昆明小鼠21只,麻醉后于双侧股部肌肉中植入bBMP各2mg,分别于1、2、4、6、8、10、12周各处死3只,切取诱导分化组织,5％戊二醛固定,行Micro—CT扫描和三维重建,运用ABA专用骨骼分析软件测定组织矿含量（tissue mineral content,TMC）,组织骨密度（tissue mineral density,TUB）,骨体积分数（bone volume fraction,BVF）,结构模型指数（structure model index,SMI）,骨小梁厚度（trabecular thickness,Tb．Th）,骨小梁数量（trabecular number,Tb．N）及皮质骨骨密度（bone mineral density,BMD）等参数,运用SPSS10．0统计软件进行统计学分析。bBMP从植入2周开始逐渐形成一椭圆形骨组织块,2～4周,异位生成骨呈疏松的新生骨,4周时组织矿含量达第一个峰值,骨小梁数量最多;随着观察时间的延长（6-12周）,异位诱导生成的椭圆形骨组织内部骨小梁逐渐吸收,数量减少,12周时骨小梁数量最少;而外层骨组织逐渐塑形成为皮质骨,12周时骨矿含量值、骨小梁厚度、组织骨密度和皮质骨骨密度均达最大值。说明bBMP具有强大的异位骨诱导能力,血供不足时,骨质降解吸收;血供充足时,骨质逐渐成熟改建。     

Structural Adaptation of Trabecular Bone Revealed by Position Resolved Analysis of Proximal Femora of Different Primates

The anisotropic arrangement of trabeculae in the proximal femur of humans and primates is seen as striking evidence for the functional adaptation of trabecular bone architecture. Quantitative evidence to demonstrate this adaptation for trabecular bone is still scarce, because experimental design of controlled load change is difficult. In this work, we use the natural variation of loading caused by a different main locomotor behavior of primates. Using high‐resolution computed tomography and advanced image analysis techniques, we analyze the heterogeneity of the architecture in four proximal femora of four primate species. Although the small sample number does not allow an interspecies comparison, the very differently loaded bones are well suited to search for common structural features as a result of adaptation. A cubic volume of interest of size (5 mm)³ was moved through the proximal femur and a morphometric analysis including local anisotropy was performed on 209 positions on average. The correlation of bone volume fraction (BV/TV) with trabecular number (Tb.N) and trabecular thickness (Tb.Th) leads to the suggestion of two different mechanisms of trabecular bone adaptation. Higher values of BV/TV in highly loaded regions of the proximal femur are due to a thickening of the trabeculae, whereas Tb.N does not change. In less loaded regions, however, lower values of BV/TV are found, caused by a reduction of the number of the trabeculae, whereas Tb.Th remains constant. This reduction in Tb.N goes along with an increase in the degree of anisotropy, indicating an adaptive selection of trabeculae. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.     

Single-trabecula building block for large-scale finite element models of cancellous bone

Recent development of high-resolution imaging of cancellous bone allows finite element (FE) analysis of bone tissue stresses and strains in individual trabeculae. However, specimen-specific stress/strain analyses can include effects of anatomical variations and local damage that can bias the interpretation of the results from individual specimens with respect to large populations. This study developed a standard (generic) ‘building-block’ of a trabecula for large-scale FE models. Being parametric and based on statistics of dimensions of ovine trabeculae, this building block can be scaled for trabecular thickness and length and be used in commercial or custom-made FE codes to construct generic, large-scale FE models of bone, using less computer power than that currently required to reproduce the accurate micro-architecture of trabecular bone. Orthogonal lattices constructed with this building block, after it was scaled to trabeculae of the human proximal femur, provided apparent elastic moduli of ∼ 150 MPa, in good agreement with experimental data for the stiffness of cancellous bone from this site. Likewise, lattices with thinner, osteoporotic-like trabeculae could predict a reduction of ∼30% in the apparent elastic modulus, as reported in experimental studies of osteoporotic femora. Based on these comparisons, it is concluded that the single-trabecula element developed in the present study is well-suited for representing cancellous bone in large-scale generic FE simulations.     

骨灵片对去势大鼠骨小梁三维结构／骨强度的干预研究

目的通过观察补肾中药骨灵片对骨质疏松大鼠腰椎松质骨二维平面和三维结构的改变以及对骨强度的影响．进一步探讨骨灵片抗骨质疏松的作用机制。方法选取3月龄SD雌性大鼠18只，随机分为假手术组。去卵巢组。骨灵片低、中、高3个剂量组（根据人鼠剂量换算标准），以雌激素为对照组。通过硬组织切片观测二维形态计量学．在其基础上利用连续切片摄像及图像数码处理技术重建腰椎骨小梁的空间结构，结合计算机3D-Doctor软件测量相关三维参数。结果去势后的模型组较之假手术组，骨小梁分离度明显升高，其余参数均显著下降（P〈0．01）；经骨灵片干预后的各组与去卵巢组比较可见，骨灵片各剂量组的骨小梁厚度显著增加．低剂量组对于骨小梁的面积百分数无明显增高，中、高剂量组在骨小梁数量、面积百分数、分离度上的改善较低剂量组显著。三维重建后的结果显示，高剂量组的骨小梁体积百分数和各剂量组的体元总数明显升高（P〈0．01）：骨灵片组与雌激素对照组相比，中剂量组在骨小梁厚度、体积百分数上的增加有显著差异（P〈0．05），高剂量组的体元总数显著升高（P〈0．01）；相关分析显示三维体元总数及骨小梁体积百分比与二维骨小梁面积百分数、骨小梁厚度、骨小梁数量呈显著正相关，与骨小梁分离度呈明显负相关。各组骨小梁体积百分数在三维重建前后无显著差异（P〉0．05）。结论构建的三维模型结合相关参数测量的结果反映出模型组在骨小梁结构上存在典型的骨质疏松改变；经骨灵片干预后的大鼠。骨小梁的结构较之模型组有明显改善，尤其是中、高剂量组在骨结构的厚度、紧密性以及体积百分数上有显著升高。结合骨灵片对骨密度以及骨力学的改善，提示该药可以通过增强骨小梁实际结构的方式，     

Development of the trabecular structure within the ulnar medial coronoid process of young dogs

This study describes the timing of development of the trabecular structure of the ulnar medial coronoid process (MCP) in the dog. The right MCPs of nine healthy golden retrievers, aged 4 to 24 weeks, without signs of secondary joint disease were dissected and scanned with microcomputed tomography (micro-CT) at a voxel size of 34 microm to determine histomorphometric parameters. Bone volume fraction and mean trabecular separation show a reciprocal pattern in time, reflecting an initial high bone density (and low trabecular separation), and then a sharp drop in density at 8-10 weeks, followed by a gradual increase to high values at 24 weeks. With a similar bone volume fraction as in young bone, the older bone shows thicker trabeculae and a more plate-like structure. This is reflected in the much smaller number of trabeculae and the lower surface/volume ratio at higher age. An anisotropic structure of the trabeculae with an orientation in the direction of the proximodistal axis of the ulna is already present at 6 weeks after birth. This primary alignment was perpendicular to the humeroulnar articular surface, matching the direction of the compressive forces applied to the MCP by the humeral trochlea. The secondary alignment appeared at 13 weeks after birth and was directed along the craniocaudal axis of the MCP, toward the attachment of the anular ligament. In comparison with data from long bones and vertebrae, the findings of a high bone volume fraction and a well-defined trabecular alignment at a very early age are remarkable. The high bone volume fraction is possibly a remnant of the fetal trabecular structure, as dogs are relatively immature at birth compared to other animals. Soon after the start of steady locomotion, the trabecular structure changes into a more mature-like structure. The early trabecular alignment is possibly a reflection of the early load-bearing function of the MCP in the elbow joint.     

A comparison of estrogen and two different doses of calcitonin in ovariectomized rats

The purpose of this study was to investigate the treatment efficacies of salmon calcitonin (SC) and estrogen in a type-I osteoporotic rat model. Sixty, 3-month-old, female Wistar rats were divided into six groups. The first group was used as the control, and the second a sham, the other four were surgically ovariectomized. 24 hours after the ovariectomy, they were either left untreated (OVX), or treated with an injection of either 17-beta estradiol (E2) 30 mcg/kg/24 hours, low-dose calcitonin (LDC) 10 IU/ kg/48 hours or high-dose calcitonin (HDC) 20 IU/kg/48 hours. 6 weeks later, the bone densities were measured by DEXA, the animals sacrificed and the femurs harvested for histomorphometric evaluation. The bone mineral densities (BMD) of the spine and proximal femur were lower in the OVX group, but only the values of the spine BMD were statistically significant. The BMD of the spine seemed to be preserved with all the treatments. The histomorphometric evaluation revealed that after the OVX the decrease in the trabecular volume was prevented by all the treatments. However, significant changes in the indices of bone formation were not shown. In conclusion, all the treatments prevented bone lost in the ovariectomized rats. Histopathological measurements of bone formation are unlikely to provide any evidence for the effects of these agents on the osteoblastic function. In the animal model of estrogen depletion, our results suggest that the calcitonin provides an important alternative therapy for postmenopausal osteoporosis.     

Establishing a rapid animal model of osteoporosis with ovariectomy plus low calcium diet in rats

The objective of this study was to rapidly develop osteoporotic model animals by combining ovariectomy with a low calcium diet in rats. Thirty, eight-week-old, female, Sprague-Dawley rats were either sham-operated (Sham) or ovariectomized (Ovx) and divided into three groups: Sham, Ovx, and Ovx + low calcium diet. Rats in the Sham and Ovx groups were fed a standard diet containing 1.1% w/w calcium while rats in the Ovx + low calcium diet group were fed a diet containing 0.1% w/w calcium. Serum osteocalcin and bone mineral density (BMD) of the lumbar vertebrae were measured 4 and 8 weeks after surgery. The rats were euthanized 12 weeks after surgery, and the BMD of the right femur and histomorphometry of the femoral neck were assessed at that time. The Ovx + low-calcium diet group had a significantly lower mean BMD of the lumbar vertebra and higher mean serum osteocalcin concentration than the Sham and Ovx groups. Twelve weeks after surgery, rats in the Ovx + low calcium diet group had a significantly lower BMD, smaller Tb.Th and Tb.N, and larger Tb.Sp of the right femoral neck than did rats in the Sham and Ovx groups. These data indicate that a low calcium diet can significantly accelerate bone loss in ovariectomized rats. Combining ovariectomy and a low calcium diet can save considerable time in the creation of osteoporotic model animals.