首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
外源性TGF-β和BMP对兔尺骨骨折愈合作用的研究   总被引:4,自引:0,他引:4  
目的:探讨外源性TGF—β和BMP对骨折愈合的作用。方法:用兔尺骨骨折模型,在骨折局部单独或联合应用TGF-β和BMP,通过X线片观察、生物力学、骨几何参数和骨痂钙含量测定对骨折愈合进行评估。结果:各骨生长因子治疗组的骨痂量、骨痂钙含量、骨愈合情况和骨折愈合后的力学强度明显优于对照组,TGF—β和BMP联合应用优于单用一种生长因子,单用TGF—β好于BMP。结论:在兔骨折周围局部应用外源性TGF-β和BMP,可促进骨折愈合,单用TGF—β的作用强于BMP,它们联合应用时,这种作用进一步增强,在促进骨折愈合方面具有协同作用。  相似文献   

2.
[目的]探讨外源性TGF-β2和BMP2复合同种异体骨对骨缺损愈合的作用。[方法]用兔桡骨骨缺损模型,在骨缺损局部单独或联合应用TGF-β2和BMP2与同种异体骨复合,A组:同种异体骨与BMP2复合;B组(对照组):自体骨;C组:同种异体骨与TGF-β2复合;D组:同种异体骨与TGF-β2、BMP2复合;通过不同时间X线片、生物力学、骨密度和骨痂钙含量的检测对骨缺损愈合情况进行评估。[结果]B组的骨痂钙含量、骨缺损愈合情况和愈合后的力学强度明显优于A、C、D组(P<0.01),D组优于A、C组(P<0.05),C组优于A组(P<0.01)。[结论]TGF-β2和BMP2在骨缺损愈合过程中均发挥了重要的作用。在兔骨缺损周围局部应用外源性TGF-β2和BMP2与同种异体骨复合,可明显促进骨缺损愈合,使骨痂量增加,增强骨折愈合后的力学强度。并且在骨折愈合时间上接近自体骨移植骨折愈合的时间,从而在临床上缩短了需要大段植骨患者治疗时间,减轻了患者痛苦。单用TGF-β2的作用强于BMP2。它们联合应用时,这种作用进一步增强,在促进骨缺损愈合方面具有协同作用。同时也为异体骨复合何种因子及因子的剂量提供可靠的参考指标。  相似文献   

3.
转化生长因子β不同给药方式对骨折愈合的影响   总被引:2,自引:1,他引:1  
目的:探讨不同给药方式给予外源性TGF-β对骨折愈合的促进作用。方法:采用兔右尺骨骨折模型。不同给药方式下在骨折区给予TGF-β,观察骨折愈合后生物力学,骨痂面积,皮质骨厚度和哈佛氏管直径的变化。结果:给予TGF-β各组的骨痂面积和最大抗弯强度明显增加,以缓释系统给予法治疗后的作用最强,对极限应力,刚度,极限负荷时能量吸收,皮质骨厚度和哈佛氏管直径则没有影响。结论:外源性TGF-β对骨折愈合有一定促进作用,不同给药方式给予TGF-β,对骨折愈合作用的效果不同,以缓释系统法给予TGF-β的效果较强。  相似文献   

4.
BMP和TGF-β对兔尺骨骨缺损修复作用的研究   总被引:2,自引:1,他引:1       下载免费PDF全文
目的 探讨外源性BMP和TGF - β对骨缺损的修复作用。 方法 采用兔尺骨干 1 5cm缺损模型 ,在骨缺损局部单独或联合应用TGF - β和BMP ,在 4、8、1 2周三个时相点进行大体形态观察、组织学、X线片观察和在 1 2周时进行生物力学测试 ,对骨缺损修复效果进行评估。结果 BMP和 /或TGF - β治疗组骨缺损均已修复 ,对照组骨缺损未修复 ,联合应用TGF - β和BMP的修复效果明显优于单用TGF - β或BMP ,而BMP又优于TGF - β ;在生物力学方面 ,TGF - β和BMP复合应用的力学强度与正常骨接近 ,单独应用时明显弱于正常骨 ,TGF - β弱于BMP。 结论 BMP和TGF - β对骨缺损均具有一定的修复作用 ,BMP的作用强于TGF - β ,复合应用时 ,二者作用进一步增强 ,在修复骨缺损方面具有协同作用  相似文献   

5.
转化生长因子β不同给药方式对骨折愈合的影响   总被引:2,自引:1,他引:1  
目的探讨不同给药方式给予外源性TGF-β对骨折愈合的促进作用.方法采用兔右尺骨骨折模型,不同给药方式下在骨折区给予TGF-β,观察骨折愈合后生物力学、骨痂面积、皮质骨厚度和哈佛氏管直径的变化.结果给予TGF-β各组的骨痂面积和最大抗弯强度明显增加,以缓释系统给予法治疗后的作用最强,对极限应力、刚度、极限负荷时能量吸收、皮质骨厚度和哈佛氏管直径则没有影响.结论外源性TGF-β对骨折愈合有一定促进作用,不同给药方式给予TGF-β,对骨折愈合作用的效果不同,以缓释系统法给予TGF-β的效果较强.  相似文献   

6.
[目的]观察补肾密骨片结合经皮自体骨髓移植对骨折延迟愈合治疗后的骨密度和生物力学性能影响。[方法]预制新西兰大耳白兔骨延迟愈合模型,将75只兔随机分为四组:A组20只,饲料中加入补肾密骨片,骨延迟愈合区注入自体红骨髓2ml;B组20只,饲料中加入补肾密骨片,骨延迟愈合区不注入自体红骨髓;C组20只,饲料中不加补肾密骨片,骨延迟愈合区注入自体红骨髓;D组15只,造成骨延迟愈合模型后,饲料中不加补肾密骨片,骨延迟愈合区不注人自体红骨髓。治疗后12周处死动物取材,行骨密度及生物力学测试。[结果]骨密度及生物力学测试均显示A组骨愈合优于B、C、D组。[结论]补肾密骨片结合经皮自体骨髓移植治疗骨折延迟愈合的骨组织的骨密度及生物力学强度优于单一骨髓移植或中药治疗。  相似文献   

7.
骨形态发生蛋白的临床应用方法研究进展   总被引:6,自引:0,他引:6  
骨形态发生蛋白(BMP)是转化生长因子(TGF-β)大家族中的一员,其在骨发生、骨诱导、骨修复和骨量保持方面发挥着重要而关键的作用。BMP表达水平的高低直接影响间充质骨祖细胞分化和骨量产生水平。研究发现内源性与外源性BMP均能发挥促进成骨作用,所以BMP被很快引入修复骨缺损、促进骨折愈合、椎体融合、假体固定等领域,并已有成熟产品问世。本文就目前BMP临床应用的主要手段(包括局部植入BMP缓释载体、闭合局部注入及体内导入BMP基因治疗)与临床研究现状进行了综述。  相似文献   

8.
一氧化氮调节骨折愈合的实验研究   总被引:3,自引:0,他引:3  
迟大明  朱悦  范广宇 《中国矫形外科杂志》2005,13(20):1577-1578,1590
[目的] 探讨一氧化氮在骨折愈合中的可能作用。[方法] Wistar大鼠60只随机分为实验组和对照组。两组动物的饮用水分别含L-硝基-精氨酸甲基脂(L-NAME)和D-硝基-精氨酸甲基脂(D-NAME),建立股骨开放骨折模型,骨折后第3d、1、2和4周,取每组6只大鼠骨折处骨痂行HE染色观察。另6只大鼠于骨折后4周行骨痂的面积、骨密度和骨折的生物力学评价。[结果] 骨折后两组大鼠体重增加无差别。HE染色光镜下见骨折后不同时期L-NAME组骨折处骨痂生成少,骨痂塑形慢,未成熟细胞比例较对照组多(P〈0.05),加入L-NAME后使骨折愈合反应减小,实验组骨痂的大小、骨密度和愈合强度均明显低于对照组,有明显的统计学意义。[结论] 在骨折愈合过程中加入L-NAME会使骨折愈合减慢,一氧化氮可能促进骨折的愈合过程。  相似文献   

9.
目的 研究转化生长因子β1(transforming growth factor β1,TGF—β1)与胰岛素样生长因子Ⅰ(insulinlike growth factor Ⅰ,IGF—Ⅰ)在低频微动引起骨折间接愈合过程中的表达与意义。方法 山东雌性高腿绵羊15只,行双侧胫骨中段横形截骨,形成2mm骨缺损,用带有微动装置的单边外固定支架固定。术后10d,随机选择一侧肢体为微动组,以频率1Hz,幅度0.25mm(30min/d)微动,4周结束;另一侧后肢不微动,为对照组。术后3、4和6周分别处死5只动物,应用免疫组织化学与RT—PCR检测骨痂组织中TGF—β1与IGF—Ⅰ的表达。结果免疫组织化学:术后3周,微动组TGF—β1在骨痂边缘的新生软骨细胞各区均有阳性表达,以增殖区最为显著;IGF—Ⅰ主要表达于软骨内骨化带边缘的成骨细胞,钙化并转化为新骨的软骨细胞与骨细胞中。对照组的相应区域,TGF—β1有少量表达,IGF—Ⅰ几乎无表达。4周,微动组新骨组织逐渐成熟,TGF—β1表达强度减弱,阳性信号主要位于细胞外基质与骨化带周围成骨细胞中;IGF—I的表达趋于高峰,主要集中在新骨表面的成骨细胞、趋于成熟的骨细胞及趋于钙化的类骨质。对照组TGF—β1与IGF—Ⅰ仅有少量表达。6周,微动组TGF—β1的表达显著衰退,IGF—Ⅰ仍有适量表达,主要在新生骨小梁骨细胞中。对照组TGF—β1与IGF—Ⅰ仅有微量表达。微动组术后3、4周TGF—β1,3、4、6周IGF—Ⅰ吸光度(A)值与对照组相比,差异有统计学意义(P〈0.05)。RT—PCR电泳示:术后3、4周,微动组骨痂中TGF—β1与IGF—Ⅰ的mRNA有较高的表达量;对照组骨痂中TGF—β1、IGF—Ⅰ的mRNA有轻度表达。术后6周,微动组TGF—β1、IGF—Ⅰ的mRNA表达量显著降低,但仍略高于对照组。微动组术后3、4周TGF—β1,3、4、6周IGF—Ⅰ A值与对照组相比,差异有统计学意义(P〈0.05)。结论低频微动在骨折愈合早期,可以促进TGF—β1与IGF—Ⅰ的表达。它们协同调节软骨内骨化的进程;后期主要由IGF—Ⅰ调节骨细胞的分化与类骨质的矿化,其可能更多的参与调节微动各个时期的细胞生物行为。  相似文献   

10.
同种异体微小颗粒骨复合BMP胶原修复骨缺损的实验研究   总被引:12,自引:0,他引:12  
目的探讨以同种异体微小颗粒骨复合BMP胶原修复节段性骨缺损的效果.方法取34只新西兰白兔,于两侧桡骨干制成长1.5 cm骨膜骨缺损,左侧(A组)植入由200mg同种异体微小颗粒骨、10 mg BMP与0.2 ml胶原的复合物;右侧(B组)植入复合0.2 ml胶原的200mg同种异体微小颗粒骨.分别于术后2、4、8、12周进行影像学,组织学检查;术后8、12周行骨密度检测;术后12周行生物力学检查.另取8只仅加入0.2 ml胶原作为空白对照组(即C组).结果放射学以及组织学检查结果显示A,B两组骨缺损区均得到了比较彻底的修复,但A组在成骨速度、骨再生量、再生髓腔结构等方面均优于B组.8、12周骨密度测试结果显示A组的骨密度值高于B组.12周的生物力学实验结果显示三点弯曲实验结果表明A组极限强度值明显高于B组,而且A组的弯曲刚度也好于B组;轴向压缩实验结果说明A组的抗压刚度优于B组;扭转实验结果指出A组的抗扭转刚度和最大扭矩分别高于B组,差异均有显著性意义(P<0.05).骨密度测定和生物力学实验结果证实了两组成骨情况的差异,这与新生骨的成熟程度不同有关.复合了BMP的A组因髓腔再通时间早,骨改建塑形更完善,新生板层骨的成熟度亦较高,耐受应力情况也更好.C组则不能产生骨性愈合.结论同种异体微小颗粒骨修复节段性骨缺损的成骨作用令人满意,复合BMP后效果更佳.  相似文献   

11.
目的观察自行设计合成的具有成骨活性的小分子多肽对小鼠股骨骨折愈合生物力学性能的影响,评价其促进骨折愈合的能力。方法选择8周龄雌性C57BL/6J小鼠40只,随机分为对照组和多肽组两组,每组各20只。所有动物制备左侧股骨骨折模型,分组植入复合PBS或多肽的胶原材料。术后第3周行三点弯曲实验,观察各标本最大载荷、弹性载荷、最大挠度、弹性挠度、最大应力、弹性模量等生物力学指标的变化情况。结果多肽组各项生物力学指标均显著高于对照组(P<0.01)。结论合成的成骨活性多肽能明显增强小鼠股骨骨折愈合的生物力学性能。  相似文献   

12.
Effect of collagen denaturation on the toughness of bone   总被引:8,自引:0,他引:8  
The purpose of this study was to explore the relationship between the integrity of collagen and biomechanical properties of bone. In this study, age (range, 5-26 years old) and gender related changes in cortical bone samples from 33 baboon femurs (15 males and 18 females) were examined. The percentage of denatured collagen was determined using a selective digestion technique. The fracture toughness, elastic modulus, yield and ultimate strength, and energy to fracture of bone were determined in three-point bending configurations. The porosity and weight fractions of the mineral and organic phase also were measured. A two-way analysis of variance showed that age dependent changes were reflected primarily in the amount of denatured collagen, fracture toughness, energy to fracture, and elastic modulus, whereas gender had effects on the fracture toughness, elastic modulus, and porosity of bone. In addition, regression analyses indicated that the percentage of denatured collagen had an inverse correlation with the toughness of bone and a positive correlation with its elastic modulus, whereas mineral content had positive correlation with the strength and elastic modulus of bone. The results of this study suggest collagen influences the toughness of bone, whereas mineral content predominantly contributes to bone stiffness and strength.  相似文献   

13.
Platelet-rich plasma (PRP) is a common therapy for acceleration of maxillofacial and spinal fusion bone-graft healing. This study analyzes the therapeutic role of PRP during long-bone fracture healing evaluated Lewis rats. Following creation of unilateral open femur fractures, either 500 microL thrombin-activated PRP (PRP treated group) or 500 microL saline (control group) were applied once to the fracture site. Fracture healing was analyzed after 1 and 4 weeks. Following 4 weeks of fracture healing, radiographic analysis demonstrated higher callus to cortex width ratio (P < 0.05) in the PRP group (PRP: 1.65 +/- 0.06; control: 1.48 +/- 0.05). Three-point load bearing showed increased bone strength following PRP treatment (PRP: 60.85 +/- 6.06 Newton, control: 47.66 +/- 5.49 Newton). Fracture histology showed enhanced bone formation in the PRP group. Immunohistochemistry and Western-blotting demonstrated healing-associated changes in transforming growth factor (TGF)-beta1 and bone morphogenetic protein (BMP)-2. Our results suggest that PRP accelerates bone fracture healing of rat femurs via modulation of TGF-beta1 and BMP-2 growth factor expression.  相似文献   

14.
目的研究生髓健骨胶囊对酒精性骨质疏松大鼠股骨生物力学的影响。方法按数字表法随机选取大鼠120只分为4组,每组30只,造模前对各组大鼠体质量进行比较,差异无统计学意义(P0.05)。模型组用酒精灌胃法造模,正常对照组用生理盐水灌胃,西药对照组用生理盐水、碳酸钙阿法D3灌胃,中药干预组用生理盐水、生髓健骨胶囊灌胃给药。干预后分别在8、12、16周后各处死10只取材,用游标卡尺测量股骨中段外径,算出截面面积。完毕后采用电子万能试验机进行股骨三点弯曲试验。指标为最大载荷、极限强度、弹性模量、最大挠度。采用SPSS 19.0软件进行统计分析(P0.05),进行t检验。结果模型组的最大载荷、极限强度、最大挠度、弹性模量与正常组比较均显著降低(P0.01),西药对照组和中药干预组均有不同程度改善。中药干预组最大载荷、极限强度、最大挠度均优于西药对照组,而弹性模量经比较差异无统计学意义(P0.05)。结论生髓健骨胶囊可明显改善大鼠股骨生物力学的性能,提高骨硬度和骨弹性,能够有效防治酒精性骨质疏松,改善大鼠股骨生物力学性能。  相似文献   

15.
This study investigated the effects of nicotine on bone mass and biomechanical properties in aged, estrogen-replete (sham-operated) and estrogen-deplete (ovariectomized) female rats. Eight month old, retired breeder, sham-operated and ovariectomized Sprague-Dawley rats were left untreated for 12 weeks to establish cancellous osteopenia in the ovariectomized group. The animals were then administered saline, low dose nicotine (6.0 mg/kg/day) or high dose nicotine (9.0 mg/kg/day) via osmotic minipumps for 12 weeks. Vertebrae and femora were collected at necropsy for determination of bone mass and strength. As expected, ovariectomy had a negative effect on most endpoints evaluated. Vertebral body bone mineral content (BMC) and density (BMD) and the structural (ultimate load and yield load) and material (ultimate stress, yield stress, and flexural modulus of elasticity) strength properties were lower in the OVX rats than in the sham-operated rats. Femoral diaphysis BMC, BMD, ultimate load, and flexural modulus were also lower in the OVX rats than in the sham-operated rats. The nicotine doses administered resulted in serum nicotine levels that averaged 1.5-4.5-fold greater than those observed in heavy smokers. Despite the high doses used, nicotine had no effect on vertebral BMC, BMD, or any of the structural and material strength properties in either the OVX or the Sham rats. In addition, nicotine had no effect on femoral diaphysis BMC, BMD, ultimate load, stiffness, ultimate stress, or flexural modulus. Femoral yield load and stress were lower in low dose nicotine-treated rats than in vehicle-treated rats. However, differences were not detected between the high dose nicotine- and vehicle-treated rats for either femoral yield load or stress. The results suggest that tobacco agents other than nicotine are responsible for the decreased bone density and increased fracture risk as observed in smokers.  相似文献   

16.
OBJECTIVES: To evaluate the effect of both high-pressure pulsatile lavage and bulb syringe irrigation on the biomechanical parameters of fracture healing using an in vivo open noncontaminated diaphyseal femoral fracture model in rats. BACKGROUND: The utility of high-pressure pulsatile lavage irrigation on soft tissue debridement has been extrapolated to a similar perceived benefit in the debridement of bone. However, there have been several reports of a possible deleterious effect that high-pressure pulsatile lavage may have on bone architecture, intramedullary bacterial and contaminant seeding, and fracture healing. Although a previous in vivo histologic study suggests damage to bone architecture and impairment of early bone formation, it remains unclear whether these microscopic findings translate to a detectable decline in the biomechanical strength of the healing fracture. To our knowledge, there have been no reports of the in vivo effects high-pressure pulsatile lavage on fracture healing in open diaphyseal fractures. MATERIALS AND METHODS: Using sterile technique, standard open transverse mid-shaft femur fractures were created in thirty-six rats randomized into three groups: a control group underwent retrograde intramedullary pinning only; a bulb syringe irrigation group and a high-pressure pulsatile lavage group underwent identical procedures as the control group, except that the osteotomy site was irrigated with bulb syringe irrigation and high-pressure pulsatile lavage, respectively, before insertion of the intramedullary pin. Six rats from each group were killed at three weeks and six weeks, and the femora was mechanically tested in bending. RESULTS: Mechanical testing of the thirty-six femora revealed that the peak bending force (17.7 +/- 10.2 N) and stiffness (21.2 +/- 5.1 N/mm) of the healing fracture in the high-pressure irrigation group were significantly lower at three weeks when compared with the control (peak force, 28.1 +/- 5.9 N; stiffness, 31.4 +/- 5.8 N/mm) and the bulb syringe (peak force, 27.7 +/- 3.3 N; stiffness, 23.6 +/- 4.5 N/mm) irrigation groups (p < 0.05). The 37 percent lower peak bending force and 32 percent lower stiffness in the high-pressure pulsatile lavage group after three weeks of fracture healing were not present in the femora tested at six weeks. The high-pressure pulsatile lavage group did reveal a trend toward a lower peak bending force and stiffness after six weeks of fracture healing when compared with the control and bulb syringe irrigation groups, but the differences were not statistically significant at the 95 percent level. CONCLUSIONS: The use of high-pressure pulsatile lavage in open noncontaminated diaphyseal femur fractures in rats has a significant negative impact on the mechanical strength of the fracture callous during the early phases (three weeks) of fracture healing. However, it appears that the early deleterious effect of high-pressure pulsatile irrigation is not apparent in the late phases (six weeks) of fracture healing. Further study is required to evaluate the effect of high-pressure pulsatile lavage on fracture healing in the presence of wound contamination, fracture comminution, and soft tissue damage. CLINICAL SIGNIFICANCE: The findings of this study suggest that selective use of high-pressure irrigation in the management of open fractures appears warranted. In situations in which high-pressure lavage may be deleterious to bone healing, alternative strategies that optimize bacterial removal from soft tissues while preserving bone architecture will need to be investigated.  相似文献   

17.
In fracture treatment, biological bone union generally depends on the bone's natural fracture healing capacity, even in surgically treated cases. Hydroxyapatite/collagen composite (HAp/Col) has high osteoconductivity and stimulates osteogenic progenitors. Furthermore, it has the potent capacity to adsorb bone morphogenetic proteins (BMPs). In this study, we prepared an injectable HAp/Col paste and evaluated its augmentation of bone union. Furthermore, the effect of HAp/Col paste combined with BMP‐2 was also evaluated. We used a rat femur osteotomy model with a defect size of 1 mm. Male Wistar rats were assigned to one of the following four groups; a control group without any implant, a HAp/Col implant group, a group that received an absorbable collagen sponge (ACS) implant impregnated with BMP‐2 (1 μg), and a group that received a HAp/Col implant impregnated with BMP‐2 implant. Micro‐CT analysis, three‐point bending tests, and histological evaluation were performed. Bone union was achieved in two of eight cases in the HAp/Col group, five of eight cases in the ACS + BMP‐2 group, and all cases in the HAp/Col + BMP‐2 group at 8 weeks post‐surgery. The control group did not achieve bone union. In addition, in the HAp/Col + BMP‐2 group, the biomechanical strength of the fused femurs was comparable to that of the contralateral intact femur; the ratio of the mechanical load at the breaking point of the osteotomy side relative to that of the contralateral side was 1.00 ± 0.151 (SD). These results indicate that HAp/Col paste with or without BMP‐2 augments bone union. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:129–137, 2018.  相似文献   

18.
Mechanical properties of fractured and intact femora have been studied in young and adult, male rats. A standardized, closed, mid-diaphyseal fracture was produced in the left femur, the right femur serving as control. The fracture was left to heal without immobilization. At various intervals, both fractured and intact femora were loaded in torsion until failure.

The fractured femora regained the mechanical properties of the contralateral, intact bones after about 4 weeks in young and after about 12 weeks in adult rats. For intact bones, both the ultimate torsional moment (strength) and the torsional stiffness increased with age of the animals, whereas the ultimate torsional angle remained unchanged. For bone as a material, however, the ultimate torsional stress (strength) and the modulus of rigidity (stiffness) increased with age only in young rats, being almost constant in the adult animals.

The various biomechanical parameters of the healing fractures did not reach those of the contralateral, intact bones simultaneously. The torsional moment required to twist a healing femoral fracture 20 degrees (0.35 radians), a deformation close to what an intact femur can resist, proved to be a functional and simple measure of the degree of fracture repair in rats.  相似文献   

19.
Demographic data reveal that due to the increasing aging of the population, complications with the musculoskeletal system will increase in the next years. One major problem in orthopedic and trauma surgery are the delayed healing or non-unions of long bone fractures. The exogenous application of growth factors can stimulate the bone healing to reduce these complications. Beside the choice of the optimal growth factor the application system is important. Therefore, we developed a new bioactive coating method for implants, which is based on a biodegradable poly(D,L-lactide) (coating thickness: 10 mum).This coating allows the incorporation of growth factors and the controlled release of these factors during the healing process without the need for further devices. The effect of different growth factors (IGF-I, TGF-beta1, and BMP-2) locally released from coated intramedullary implants on fracture healing was investigated with biomechanical and histological analysis in rats. All investigated growth factors stimulated the fracture healing as assessed with biomechanical tests and histological analysis. The local application of combined IGF-I and TGF-beta1 had the most stimulating effect on fracture healing, followed by the effect of BMP-2, IGF-I, and TGF-beta1 alone. Bioactive coating of biomechanical well-established implants can on the one hand stabilize the fracture and on the other hand stimulate healing processes to increase healing and to reduce the rate of complications.  相似文献   

20.
Inexpensive, commercially produced devices that directly measure bone strength in vivo are not currently available. Mechanical response tissue analysis (MRTA), a unique prototype device, is an in vivo vibrational test that measures transverse bending stiffness (a measure of whole bone strength expressed as the product of estimated Young's modulus of elasticity and cross-sectional moment of inertia, EI, Nm2) at ulna midshaft. We compared speed of sound (SOS; [m/s]) in ulna cortical bone using a commercially available axial transmission quantitative ultrasound (QUS) device with EI using MRTA. Dual-energy X-ray absorptiometry (DXA) was used to provide an estimate of ulna size (cm2), bone mineral content (BMC; [g/cm]) and areal bone mineral density (BMD; [g/cm2]). The objective of the study was to determine if ulna SOS--alone or in combination with BMD from DXA--was correlated with ulna EI, thus becoming a surrogate measure of transverse bending stiffness, and thus whole bone strength. Data were collected from 138 female volunteers (18-86 yr). EI and SOS were significantly correlated, r = +0.218, p = 0.01, but r2 was very low, 4.8%. SOS and total ulna BMD were combined to estimate elastic modulus, which correlated with EI, r = +0.377, p < 0.0001; however, the correlation was not significantly better than with SOS alone. We conclude that axial transmission QUS is not a strong surrogate in vivo technique for estimating transverse bending stiffness.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号