续断对大鼠骨质疏松性骨折愈合影响的生物力学实验研究

目的:观察续断对大鼠去卵巢骨质疏松性骨折模型骨折愈合中生物力学性能的影响。材料与方法:选取30只4月龄大鼠,分为假手术骨折对照组、去卵巢骨折对照组、去卵巢骨折中药处理组。后两组去卵巢3月造成绝经后骨质疏松模型,之后三组均造成桡骨远端骨折,灌药1月后检测桡骨骨痂生物力学强度。结果:中药处理组最大剪切力17.76±1.25N,剪切应力1.12±0.13N/mm2,生物力学性能与基础骨折对照组相接近,明显优于去卵巢骨折对照组(P<0.01)。结论:续断能改善骨质疏松性骨折愈合骨痂的生物力学性能,具有一定的促进骨折愈合的作用。     

骨质疏松性骨折愈合中骨改建的动态参数及骨密度变化

背景：当骨质疏松骨强度下降时,遭受轻微创伤或其他各种风险因素均易发生骨折。 目的：观察骨质疏松性骨折愈合过程中骨小梁组织学变化,骨密度及骨矿化沉积率的改变。 方法：SD大鼠随机分为骨质疏松组与对照组,骨质疏松组大鼠切除双侧卵巢,术后3个月,建立骨折模型。骨折后4,8,12,16 周,荧光显微镜下观察骨改建的动态参数,双能X线骨密度仪下测定骨痂组织的骨密度;骨折后1,2,4,6,8,12,16 周,应用自动图像系统测量骨组织形态。 结果与结论：骨质疏松组大鼠成熟小梁骨占骨痂面积比对照组小,且小梁骨厚度变薄、小梁骨间距较宽,骨质疏松组骨小梁表面荧光标记百分比及骨痂组织骨密度低于对照组;而骨矿化沉积率高于后者对照组。说明在骨质疏松性骨折愈合过程中,骨痂组织的组织学的异常改变导致骨折愈合质量的降低。     

仙灵骨葆对骨质疏松性骨折骨痂血管形成的影响

背景：骨质疏松对骨折愈合早期的影响尚存争议,仙灵骨葆对骨质疏松性骨折愈合的影响及其机制尚有待深入研究。 目的：观察骨质疏松对大鼠股骨干骨折愈合的影响,以及仙灵骨葆对骨质疏松性骨折愈合的作用。 方法：将50只雌性12周龄Sprague-Dawley大鼠随机分成5组：假手术组、骨折组、去卵巢组、去卵巢+骨折组及治疗组,后3组切除大鼠双侧卵巢制备去卵巢模型,骨折模型于去卵巢后4周制备,为股骨干中段横行骨折。治疗组在去卵巢及骨折基础上灌胃给予仙灵骨葆250 mg/(kg•d)。给药3周,取去卵巢+骨折组、骨折组和治疗组大鼠骨折侧标本行X射线摄像仪摄片后,测量其骨密度,苏木精-伊红染色观察骨痂组织的病理学改变并计数血管,免疫组织化学染色检测骨痂组织骨形态发生蛋白2的表达。 结果与结论：去卵巢处理后大鼠的骨密度、计算机X射线摄像仪摄片评分显著降低(P < 0.05),仙灵骨葆可在一定程度上提高去卵巢后骨折大鼠的骨密度及X射线摄像仪摄片评分,但差异无显著性意义(P > 0.05);仙灵骨葆可提高去卵巢后骨折大鼠骨痂组织的血管数量(P < 0.05),但对骨形态发生蛋白2的表达无影响。提示,去卵巢后大鼠骨折早期愈合过程延迟,仙灵骨葆可促进骨质疏松大鼠骨折愈合早期血管的形成。     

辛伐他汀涂层内固定对大鼠骨质疏松骨折愈合晚期的影响

背景：降脂类药物辛伐他汀具有一定的促进骨形成作用潜能,局部应用效果更佳。先前研究对骨质疏松大鼠骨折愈合中期的观察证实辛伐他汀涂层内固定可促进骨质疏松大鼠骨折愈合,但其对骨折愈合晚期的影响未见报道。 目的：观察局部应用辛伐他汀涂层内固定对骨质疏松大鼠骨折愈合晚期进程的影响。 方法：将雌性SD大鼠分为单纯骨折组、骨质疏松性骨折组及辛伐他汀干预组。单纯骨折组仅暴露腹腔卵巢不予切除,其余2组采用双侧卵巢切除法建立骨质疏松模型。卵巢切除后6周,所有大鼠建立股骨中段开放性骨折模型,单纯骨折组、骨质疏松性骨折组及辛伐他汀干预组分别采用无涂层、聚乳酸涂层和辛伐他汀复合聚乳酸涂层克氏针内固定。骨折造模后12周分析骨折侧股骨骨密度,X射线摄片和苏木精-伊红染色分析骨折愈合情况,免疫组织化学分析骨形态发生蛋白2在骨折局部的表达。 结果与结论：骨密度检测结果提示股骨全长及中段骨密度骨质疏松性骨折组、辛伐他汀干预组显著低于单纯骨折组,辛伐他汀干预组骨折部位骨密度显著高于骨质疏松性骨折组。X射线摄片结果提示,单纯骨折组骨折两端对位、对线良好,骨痂与骨皮质密度接近相同并相互连接,塑形基本完成;骨质疏松性骨折组愈合质量差,骨痂密度浅淡,部分标本仍见模糊的骨折线;辛伐他汀干预组骨折线消失,骨痂填满骨缺损,骨膜反应深,单纯骨折组、辛伐他汀干预组X射线评分显著高于骨质疏松性骨折组(P < 0.05)。苏木精-伊红染色提示,骨质疏松性骨折组骨折愈合进程较单纯骨折组延迟,辛伐他汀干预组骨小梁较骨质疏松性骨折组更规则有序。免疫组化结果提示各组大鼠骨形态发生蛋白2的表达水平差异无显著性意义。提示辛伐他汀局部应用可有效促进骨质疏松大鼠骨折愈合。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

植物雌激素对去卵巢大鼠骨质疏松性骨折愈合的影响

目的观察植物雌激素对卵巢去势大鼠骨折愈合过程中骨痂骨密度的影响。方法复制卵巢去势大鼠骨质疏松模型并制造股骨中段闭合性骨折,然后进行克氏针髓腔内固定,观察大鼠骨折内固定后骨痂与近骨痂段股骨骨密度的变化。结果异黄酮组、雌二醇组和假手术组骨痂的骨密度高于无用药组,差异具有统计学意义(P<0.05);而异黄酮组、雌二醇组和假手术组之间没有显著差别。结论植物雌激素能够显著提高骨质疏松大鼠骨痂及近骨痂段骨组织的骨密度、促进骨折愈合,与雌二醇组作用相近。     

仙灵骨葆对大鼠骨质疏松性骨折愈合的影响

背景：骨质疏松可延迟骨折愈合,仙灵骨葆对骨质疏松性骨折愈合的影响及其机制尚有待研究。 目的：观察骨质疏松对大鼠股骨干骨折愈合的影响以及仙灵骨葆的干预效果及其作用机制。 方法：50只3月龄雌性SD大鼠随机分成5组：正常对照组、骨质疏松组、正常骨折组、骨质疏松性骨折组、治疗组,前2组每组6只,后3组每组12只。去除大鼠双侧卵巢制备骨质疏松模型,8周后制备右侧股骨干中段横行骨折模型。治疗组给予仙灵骨葆灌胃250 mg/(kg•d),正常骨折组、骨质疏松性骨折组灌胃等量生理盐水,灌胃6周。 结果与结论：去卵巢后8周骨质疏松组的骨密度显著低于正常对照组(P < 0.05),说明骨质疏松模型制作成功;灌胃6周,骨质疏松性骨折组骨密度、X射线摄片评分、最大载荷均显著低于正常骨折组和治疗组(P < 0.05),但给予仙灵骨葆的治疗组仍显著低于正常骨折组(P < 0.05)。以上结果提示骨质疏松大鼠骨折愈合过程延迟,仙灵骨葆对骨质疏松大鼠骨折愈合具有积极促进作用。     

血管内皮生长因子在卵巢切除大鼠骨折愈合骨痂中的表达

背景:血管内皮生长因子在骨折愈合过程中起着重要作用,研究发现去卵巢大鼠影响骨折愈合,但其作用机制尚未明确。目的:观察去卵巢大鼠股骨骨折愈合中骨痂组织学变化以及血管内皮生长因子的表达与分布,探讨骨质疏松对大鼠骨折修复的影响与血管内皮生长因子对其的作用。方法:取12周龄雌性Sprague-Dawley大鼠20只,随机分成假手术组和去卵巢组。制造股骨骨折模型,于术后4周处死,各组截取大鼠右侧股骨标本后行计算机X射线摄像仪摄片观察骨折愈合情况,并应用双能X射线骨密度仪测量右股骨骨密度,苏木精-伊红染色观察骨痂生长情况及其组织形态,免疫组织化学染色测定血管内皮生长因子表达。结果与结论:骨折后4周,去卵巢组形成的骨痂中含有的软骨骨痂比例高与假手术组。去卵巢组中表达血管内皮生长因子的成骨细胞数目少于假手术组。提示骨质疏松大鼠骨折愈合形成的骨痂质量较差,血管内皮生长因子在成骨细胞中的表达减少是骨质疏松骨折愈合质量下降的可能因素之一。     

骨质疏松性骨折骨痂软骨细胞CD44和纤连蛋白的表达

目的:探讨骨质疏松性骨折愈合过程中胞内信号因子CD44及其配体纤连蛋白(FN)在骨痂软骨细胞的表达情况。方法:建立SD大鼠骨质疏松性股骨骨折愈合模型作为实验组以及二期股骨骨折愈合模型作为对照组,分别于骨折后10、20、30d和40d取材,对骨痂进行H-E染色及CD44、FN免疫组织化学显色。结果:在骨痂组织中CD44和FN的表达及分布在时空上有一致性。在实验组中,随着骨折愈合进程的发展,软骨细胞CD44与FN的表达逐渐减少,而对照组中,CD44与FN共同表达于骨折愈合各阶段的各区软骨细胞中。结论:大鼠骨质疏松性骨折愈合过程中骨痂软骨细胞CD44、FN的表达明显弱于正常二期骨折愈合过程中的表达,提示CD44和FN在软骨细胞中表达的明显减少可能是造成骨质疏松性骨折骨痂软骨组织向骨组织演变缓慢的原因之一。     

阿仑膦酸钠可抑制骨质疏松性骨折的愈合

背景：阿仑膦酸钠作为治疗骨质疏松症的首选药物已被临床广泛应用。 目的：观察阿仑膦酸钠对骨质疏松性骨折大鼠股骨干骨折愈合的影响。 方法：将SD大鼠随机分成3组：假手术组,模型组和阿仑膦酸钠组。模型组及阿仑膦酸钠组于卵巢切除后4周进行右股骨干中段横行骨折,克氏针固定。阿仑膦酸钠组建模后皮下注射阿仑膦酸钠。 结果与结论：骨折造模后3及6周,阿仑膦酸钠组右股骨整体骨密度和远段骨密度高于模型组(P < 0.01),与模型组相比,阿仑膦酸钠组骨折端骨痂体积大、骨痂数量多,软骨性骨痂向骨性骨痂转换过程延迟,骨折愈合过程减慢,破骨细胞数量显著降低(P < 0.05)。结果证实,阿仑膦酸钠对大鼠骨质疏松性骨折愈合过程有抑制作用,其机制可能与阿仑膦酸钠抑制破骨细胞活性使骨痂钙化过程减慢有关。     

克氏针表面涂有辛伐他汀聚乳酸涂层对卵巢切除大鼠股骨骨折愈合的影响

背景：前期研究已经证实口服应用辛伐他汀可以显著提高骨折愈合质量,加快骨折愈合的速度。 目的：进一步验证克氏针表面涂有辛伐他汀聚乳酸涂层后对卵巢切除大鼠股骨骨折愈合的影响。 方法：3月龄雌性SD大鼠40只,随机分为单纯骨折组、去势骨折组、涂层对照组及涂层治疗组,后3组大鼠行双侧卵巢切除制作骨质疏松模型,4周后所有大鼠行闭合性股骨中段骨折克氏针内固定。涂层对照组所用克氏针表面涂以聚乳酸,涂层治疗组克氏针表面涂以混有辛伐他汀(50 μg/支)的聚乳酸,其余两组克氏针表面未经特殊处理。 结果与结论：与涂层对照组相比,涂层治疗组在骨折后6周,X射线表现骨折线模糊,骨痂填满骨缺损,骨膜反应较深,X射线评分显著增高(P < 0.05)。组织病理学显示涂层治疗组骨痂内新生骨小梁数量较多,排列致密均匀;免疫组织化学染色骨形态发生蛋白2阳性细胞表达强烈,积分吸光度值显著高于涂层对照组(P < 0.05),但血管内皮生长因子表达水平在骨折后6周时显著低于涂层对照组和模型组(P < 0.05)。提示混有辛伐他汀的聚乳酸涂层可以促进大鼠骨质疏松性股骨骨折的愈合。 关键词：辛伐他汀;聚乳酸;骨质疏松;骨折;卵巢切除;大鼠 doi:10.3969/j.issn.1673-8225.2012.12.004     

Effects of leptin on femoral fracture in rats

In this study, our objective was to evaluate effects of leptin on fracture healing in rats. Seventy two male SpragueDawley (SD) rats were randomized into 3 groups. Standardized femoral fractures were created in all the rats. Group A was treated with 1 mL normal saline (NS), group B with 0.3 μg/kg leptin in 1 mL NS, and group C with 0.5 μg/kg leptin in 1 mL NS for 2 weeks intraperitoneally. Each group was divided into three subgroups including 8 rats for evaluation at 2, 4 and 8 weeks. Radiological evaluation showed that callus formation of group B and C was all significantly higher than group A at 8 weeks (P = 0.04 and P = 0.013, respectively). There was no statistically significant difference in fracture healing between group B and group C at 8 weeks (P = 0.197). Histological evaluation revealed fracture healing of group B and C was better than group A at 4 weeks (P = 0.01 and P = 0.002, respectively) and 8 weeks (P = 0.008 and P = 0.003, respectively). Micro-computed tomography (Micro-CT) analysis demonstrated that greater amounts of bony callus and evidence of bone fusion were observed in group B and C at 4 weeks (P = 0.02 and P = 0.04, respectively) and 8 weeks (P = 0.005 and P = 0.001, respectively) compared to group A. Group C also had better fracture healing than group B at 8 weeks (P = 0.01). In conclusion, leptin has a positive effect on rat femoral fracture healing.     

Characterising neovascularisation in fracture healing with laser Doppler and micro-CT scanning

Vascularity of the soft tissues around a bone fracture is critical for successful healing, particularly when the vessels in the medullary canal are ruptured. The objective of this work was to use laser Doppler and micro-computer tomography (micro-CT) scanning to characterise neovascularisation of the soft tissues surrounding the fracture during healing. Thirty-two Sprague–Dawley rats underwent mid-shaft osteotomy of the left femur, stabilised with a custom-designed external fixator. Five animals were killed at each of 2, 4 days, 1, 2, 4 and 6 weeks post-operatively. Femoral blood perfusion in the fractured and intact contralateral limbs was measured using laser Doppler scanning pre- and post-operatively and throughout the healing period. At sacrifice, the common iliac artery was cannulated and infused with silicone contrast agent. Micro-CT scans of the femur and adjacent soft tissues revealed vessel characteristics and distribution in relation to the fracture zone. Blood perfusion dropped immediately after surgery and then recovered to greater than the pre-operative level by proliferation of small vessels around the fracture zone. Multi-modal imaging allowed both longitudinal functional and detailed structural analysis of the neovascularisation process.     

ZHD─1型微冲击振动仪诱发骨折端微动对骨折愈合的影响

兔实验性股骨干骨折髓针内固定，术后随机分成振动组、对照组，振动组用ＺＨＤ─１型微振仪（冲击力大小４３克，频率０．５Ｈｚ）诱发骨折段微动，对照组仅作对照，结果证明，振动组骨折愈合快，肢体血流量、骨痂光密度、骨折段的扭距优于对照组。     

雌激素对骨质疏松性骨折愈合过程BMP-4基因表达的影响

目的：研究雌激素对骨质疏松性骨折愈合骨形态发生蛋白-4（bone morphogenetic protein-4,BMP-4）基因定位分布的影响。 方法： 选用健康SD大鼠，随机分为卵巢切除（OVX）组、假手术对照（sham）组和雌激素替代治疗组（OVXE）。制成胫骨骨折愈合模型并分别于骨折后不同时点处死大鼠取材。通过光镜、电镜观察形态学和超微结构变化；采用原位杂交方法观察雌激素对BMP-4基因表达影响。 结果： (1)OVX组在骨痂形态及成骨细胞和破骨细胞活性与OVXE组比较有明显差异，较sham组差异更大。（2）骨折后1-3 d BMP-4 mRNA表达强度:sham组相似文献   

The effects of alpha-tocopherol supplementation on fracture healing in a postmenopausal osteoporotic rat model

OBJECTIVE:

Osteoporosis increases the risk of bone fractures and may impair fracture healing. The aim of this study was to investigate whether alpha-tocopherol can improve the late-phase fracture healing of osteoporotic bones in ovariectomized rats.

METHOD:

In total, 24 female Sprague-Dawley rats were divided into three groups. The first group was sham-operated, and the other two groups were ovariectomized. After two months, the right femora of the rats were fractured under anesthesia and internally repaired with K-wires. The sham-operated and ovariectomized control rat groups were administered olive oil (a vehicle), whereas 60 mg/kg of alpha-tocopherol was administered via oral gavage to the alpha-tocopherol group for six days per week over the course of 8 weeks. The rats were sacrificed, and the femora were dissected out. Computed tomography scans and X-rays were performed to assess fracture healing and callus staging, followed by the assessment of callus strengths through the biomechanical testing of the bones.

RESULTS:

Significantly higher callus volume and callus staging were observed in the ovariectomized control group compared with the sham-operated and alpha-tocopherol groups. The ovariectomized control group also had significantly lower fracture healing scores than the sham-operated group. There were no differences between the alpha-tocopherol and sham-operated groups with respect to the above parameters. The healed femora of the ovariectomized control group demonstrated significantly lower load and strain parameters than the healed femora of the sham-operated group. Alpha-tocopherol supplementation was not able to restore these biomechanical properties.

CONCLUSION:

Alpha-tocopherol supplementation appeared to promote bone fracture healing in osteoporotic rats but failed to restore the strength of the fractured bone.     

卵巢切除股骨骨折大鼠骨愈合中降钙素的作用

背景：降钙素可活化腺苷酸环化酶蛋白激酶A通路及磷脂酶C通路,抑制破骨细胞的活性,可能治疗骨质疏松性骨折。 目的：观察降钙素对去卵巢大鼠股骨骨折愈合的作用。 方法：构建双侧卵巢切除骨质疏松右股骨骨折SD大鼠模型,然后分别皮下注射生理盐水和降钙素(16 IU/kg),隔日1次,于骨折后3周和6周测量右股骨行骨密度,苏木精-伊红及抗酒石酸酸性磷酸酶染色,骨形态发生蛋白2及血管内皮生长因子免疫组化染色。 结果与结论：骨折后给予降钙素治疗的大鼠抗酒石酸酸性磷酸酶染色阳性细胞积分吸光度值较生理盐水治疗的大鼠显著减少(P < 0.05)。骨折后3周,两组骨折线均较清晰,骨痂体积无明显差别,骨折愈合以软骨内化骨过程为主,骨密度无显著性差异(P > 0.05)。骨折后6周,两组骨折线较模糊,骨痂体积无差别,骨小梁排列较有序,用药组股骨骨密度较对照组升高(P < 0.05)。两组在骨折后3周和6周的骨形态发生蛋白2及血管内皮生长因子差异无显著性意义(P > 0.05)。证实降钙素可以抑制去卵巢大鼠骨折部位破骨细胞活性,但无明显促进大鼠股骨骨折愈合的作用。