成骨过程中微小RNAs调控作用的研究进展

目的 对微小RNAs(microRNAs,miRNAs)在成骨过程中的调控作用及作用机制的研究现状、存在的争议以及研究方向作一综述.方法 广泛查阅近年来有关成骨过程中miRNAs的调控作用及作用机制的文献,进行总结与分析.结果 miRNAs是近来成骨研究的热点,越来越多资料显示其在骨化过程中发挥重要作用,但确切机制尚未清楚.结论 通过应用miRNAs技术促进成骨细胞分化,具有巨大的应用前景,同时将可能获取成骨细胞分化中的miRNAs调控机制,也有利于建立成骨效果比较的研究模型.     

富血小板血浆在颌面部非血管化骨移植中的应用

目的对近年来国内外有关富血小板血浆（platelet—rich plasma，PRP）促进骨形成的作用和在颌面部非血管化骨移植中的应用进行综述。方法广泛查阅相关文献，对PRP促进骨形成作用机制进行综合分析。结果PRP应用于非血管化骨移植中有促进新骨形成的作用，其机制可能与血小板本身含有各类细胞因子相关。且已有学者将其应用于临床颌面部骨缺损修复，并取得较好效果。结论PRP存在可能的促新骨形成作用，但其具体作用机制、作用持续时间以及效应与浓度的关系仍有待进一步的研究。     

原位组织工程技术在骨与软骨修复领域的应用进展北大核心CSCD

目的总结原位组织工程技术在骨与软骨缺损修复领域的应用以及研究进展。方法查阅国内外近年来有关原位组织工程技术在骨与软骨缺损修复方面的相关文献,并进行综合分析。结果原位组织工程技术在骨与软骨缺损修复方面展现了一定的修复效果,但其生物学机制研究尚不足。目前研究主要以动物实验为主,临床修复效果有待进一步研究。结论随着原位组织工程技术的发展,运用该方法构建的修复材料具有广阔应用前景,但其相关细胞因子的生物学机制尚需进一步研究。     

富血小板血浆在骨组织修复中的应用现状

富血小板血浆(PRP)是自体血小板的浓缩体,含有丰富的血小板,是自体生长因子的来源,其应用已成为骨缺损修复研究领域近年来的热点课题.PRP对骨前体细胞增殖有明显的促进作用,并存在剂量效应,而在是否促进骨前体细胞分化上存在争议.在动物和临床骨缺损修复中,虽然大量实验依据支持PRP有明显的促进骨缺损修复作用,但仍有少数实验结果对之持有怀疑.在临床广泛开展PRP应用于骨缺损修复之前,需进一步研究PRP制备、应用标准、各因子间相互作用、促进成骨的机制、最佳血小板浓集程度、PRP应用的最佳比例,以及PRP在四肢骨缺损和大的骨缺损修复中的作用等.     

富血小板血浆与骨再生

富血小板血浆是自体血离心后的产物,其最初被作为一种生物凝胶和屏障膜应用于临床,主要作用为提高止血效果。近几年有研究发现富血小板血浆对骨再生有促进作用,这使其成为骨科领域又一热门的研究课题。本文简要综述了富血小板血浆在组成成分、临床应用、对骨再生的作用机制、最佳作用浓度等方面的研究进展,并讨论了其目前主要存在的问题。资料表明富血小板血浆含有多种高浓度的骨生长所需要的生长因子,它们在骨再生的各个不同阶段通过直接或者间接的作用促进着细胞的分化与增殖,从而促进新骨的生存,而这种促进骨再生的作用在血小板处于中等浓缩浓度时作用最强。目前在国外已有部分学者将富血小板血浆应用于临床,并取得了一定的疗效,这有可能使其成为促进骨缺损修复的又一有效方法,具有良好的应用前景。     

原位组织工程技术在骨与软骨修复领域的应用进展

目的总结原位组织工程技术在骨与软骨缺损修复领域的应用以及研究进展。方法查阅国内外近年来有关原位组织工程技术在骨与软骨缺损修复方面的相关文献,并进行综合分析。结果原位组织工程技术在骨与软骨缺损修复方面展现了一定的修复效果,但其生物学机制研究尚不足。目前研究主要以动物实验为主,临床修复效果有待进一步研究。结论随着原位组织工程技术的发展,运用该方法构建的修复材料具有广阔应用前景,但其相关细胞因子的生物学机制尚需进一步研究。     

骨髓干细胞治疗骨不连研究进展

近年随着对骨折愈合机制和骨髓间充质干细胞(BMSC)功能的研究深入,应用自体骨髓与BMSC治疗骨不连取得了可靠的理论与-临床应用疗效.研究证实,局部富集的BMSC可被精确诱导分化为成骨前体细胞,一定浓度的BMSC在一定条件下具有可靠的成骨效果.该文就BMSC与骨折愈合、骨不连治疗的体外动物实验研究和临床应用研究进展作一...     

颗粒骨打压植骨结合非骨水泥臼固定在髋臼翻修中的应用

目的 探讨颗粒骨打压植骨结合非骨水泥臼在髋臼翻修中的临床应用.方法 应用颗粒骨打压植骨结合非骨水泥臼技术重建髋臼骨缺损10例,术中使用异体颗粒骨直径4～6 mm,髋臼假体均为生物型髋臼,上2或3枚螺钉固定,内衬均为高交联聚乙烯.结果 切口均一期愈合,无感染、脱位等并发症发生.随访9～28个月,平均19.5个月,X线片上髋臼骨床、颗粒骨及假体界面未见明显透亮带存在,原骨缺损区修复良好.Harris评分术前平均38.1分,术后平均85.5分.结论 颗粒骨打压植骨结合非骨水泥臼固定方法可有效修复髋关节翻修中髋臼AAOSⅡ、Ⅲ型骨缺损,恢复骨量,并能提供良好的早期稳定性.     

人工骨传导材料的研究进展

目的 综述人工骨传导材料基础与临床应用研究进展。方法 广泛查阅近年国内外相关文献进行回顾与综合分析。结果 人工骨传导材料的基础与临床应用研究已取得明显进展，并已成为骨组织工程研究的热点之一。部分人工骨传导材料已进入临床应用阶段，并取得良好临床效果。结论 人工骨传导材料在骨组织工程中具有广阔的应用前景，它为临床治疗骨缺损提供了新的方法。如何改善人工骨传导材料的微观结构、宏观形状、导入骨诱导机制以及加速新骨形成将是今后研究的重点，复合人工骨材料将是新的研究热点。     

异体冻干颗粒骨复合骨髓基质干细胞源性成骨细胞体外生物相容性研究

[目的]评价异体冻干颗粒骨体外生物相容性,为其作为骨组织工程支架材料的临床应用提供实验依据。[方法]4周龄SD大鼠,雌雄不限,采用全骨髓贴壁法体外培养骨髓基质干细胞(BMSCs),取生长状态良好的第3代BMSCs行成骨诱导培养并鉴定。制备异体冻干颗粒骨浸提液,将成骨诱导7d的BMSCs加入浸提液作为实验组,未加浸提液的为对照组,培养1、3、5d,采用MTT法检测异体冻干颗粒骨浸提液对细胞增殖的影响。成骨诱导7d的BMSCs按1×106/ml接种于异体冻干颗粒骨上,倒置相差显微镜、扫描电镜观察与其复合培养的细胞在材料上的生长情况;酶消化法消化复合于冻干颗粒骨上的成骨细胞,流式细胞仪检测细胞周期变化。[结果]BMSCs成骨诱导7d,ALP染色示胞浆内可见阳性蓝染颗粒,胞核呈红色。MTT法检测结果显示细胞在浸提液中生长与增殖状态良好,实验组与对照组差异无统计学意义(P0.05);倒置相差显微镜可见颗粒骨表面粘附多数成骨细胞;扫描电镜观察可见细胞在材料表面粘附、伸展并能增殖、分泌产生细胞外基质;流式细胞术检测显示,异体颗粒骨对细胞周期无影响,实验组细胞均为正常2倍体细胞。实验组与对照组差异无统计学意义(P0.05)。[结论]异体冻干颗粒骨无细胞毒性并具有良好的组织细胞相容性,为其临床应用提供了实验依据。     

Incomplete incorporation of morselized and impacted autologous bone graft: a histological study in 4 intracorporally grafted lumbar fractures

Morselized and impacted bone allografts are used successfully in hip and knee revisions, but experiments using bone chambers indicate that impaction actually can delay ingrowth of new bone into a graft. To understand the remodeling and incorporation process of morselized and impacted grafts, we studied the incorporation of morselized impacted autografts in lumbar fractures histologically. 4 patients were operated on for Th XII-LI fractures. The fractures were stabilized by VSP plates and transpedicular screws in the vertebrae above and below the fractured one. Autologous bone graft was packed into the fractured vertebral body through one of the pedicles. After 18-20 months, the plates were removed and biopsies were obtained from various locations in the fractured vertebra. All fractures were at this time clinically and radiographically healed. Histologically, in all cases, large areas of the autograft in the vertebral body were unvascularized and partially or entirely necrotic. As with morselized bone in hip revisions, evaluation of graft incorporation requires histological examination. Full osseous incorporation of a graft is not always necessary for a good clinical result.     

Incomplete incorporation of morselized and impacted autologous bone graft: A histological study in 4 intracorporally grafted lumbar fractures

Morselized and impacted bone allografts are used successfully in hip and knee revisions, but experiments using bone chambers indicate that impaction actually can delay ingrowth of new bone into a graft. To understand the remodeling and incorporation process of morselized and impacted grafts, we studied the incorporation of morselized impacted autografts in lumbar fractures histologically.

4 patients were operated on for Th XII-LI fractures. The fractures were stabilized by VSP plates and transpedicular screws in the vertebrae above and below the fractured one. Autologous bone graft was packed into the fractured vertebral body through one of the pedicles. After 18-20 months, the plates were removed and biopsies were obtained from various locations in the fractured vertebra. All fractures were at this time clinically and radiographically healed. Histologically, in all cases, large areas of the autograft in the vertebral body were unvascularized and partially or entirely necrotic. As with morselized bone in hip revisions, evaluation of graft incorporation requires histological examination. Full osseous incorporation of a graft is not always necessary for a good clinical result.     

Morselized bone grafting of defects in revision total knee arthroplasty.

In a prospective, multicenter study evaluating one revision knee system, 33 of 409 patients underwent morselized bone grafting for tibial and femoral defects. Fifty-four percent of defects were bicondylar and the defect volumes averaged 36 cc3. There was no difference in preoperative or postoperative knee scores between patients undergoing morselized grafting and the entire group. Radiographic evaluation showed remodeling of the grafted areas consistent with viable incorporation of the graft. The incidence of radiolucent lines, at 2 years followup, was not different between the patients who received grafting and the patients who did not receive grafting. There have been no clinical failures or reoperations in the patients who received morselized bone grafting. Morselized bone grafting seems to offer a viable alternative in the reconstruction of osseous defects in patients undergoing revision total knee arthroplasty.     

The role of femoral stem extension in total knee arthroplasty

Although stemmed femoral components often are used in revision total knee arthroplasty, no quantitative comparison of the relative stability of a femoral component with and without a stem has been performed previously. A radiostereophotogrammetric analysis was performed to determine the influence of stem extension on mechanical stability in a laboratory experiment. In addition, the contribution of impacted morselized bone graft used for reconstruction of bone defects to stability was determined. Ten fresh frozen distal femoral specimens, of which the bone mineral density was measured, were prepared to fit a cemented femoral component with an uncemented stem. A cyclic axial load of 750 N was applied to the medial part of the femoral component. The loading test was repeated after creation of a standard, unicondylar, uncontained medial bone defect, after reconstruction of the defect with impacted morselized bone graft, after disconnecting the stem from the component, and after removal of the morselized bone graft. A significant difference was found in rotation and translation of the femoral component with the stem and after its functional removal. The femoral component rotated significantly into varus and internal rotation, and the tip of the stem translated significantly laterally after disconnection of the stem. A linear correlation between bone mineral density in the femoral neck and the radiostereophotogrammetric motion data was absent, but a bone mineral density threshold level of 0.55 g/cm2 was present, below which stability decreased considerably. Morselized bone graft provided only a minor contribution to stability compared with a stem.     

The evaluation of a biphasic calcium phosphate ceramic for use in grafting long-bone diaphyseal defects

The effectiveness of a sintered hydroxyapatite-tricalcium phosphate (HA-TCP) ceramic in bridging large diaphyseal defects in the canine ulna was studied. One-hundred percent morselized HA-TCP, a 50:50 mixture of morselized HA-TCP, and autogenous cancellous bone, and 100% autogenous cancellous bone were used to bridge 2.5-cm defects in the left ulnae of three groups of six dogs each. At 24 weeks the ulnae were explanted and studied by radiography, microradiography, mechanical testing, and histology. Pure HA/TCP was not osteoinductive, and four of six ulnae in this group progressed to a fibrous nonunion. The HA/TCP-cancellous bone mixture and pure cancellous bone were approximately equal in effect, leading to good callus formation at 4 weeks and strong bony union by 24 weeks, with no evidence of bioincompatibility. Morselized HA/TCP promises to be useful as a graft extender when mixed with autogenous cancellous bone.     

颗粒骨经椎弓根椎体内外植骨融合内固定治疗胸腰椎骨折

目的探讨脊柱后路颗粒骨经椎弓根椎体内外植骨短节段椎弓根钉内固定治疗胸腰椎骨折可行性。方法将70例胸腰椎骨折随机分为两组:A组(n=20)采用颗粒骨经椎弓根椎体内植骨融合短节段椎弓根钉内固定;B组(n=50)采用单纯短节段椎弓根钉内固定。对后凸畸形角度及矫正角度、椎体前缘高度以及椎管矢状径进行测量,采用Frankel功能分级和Denis疼痛分级方法进行神经功能改变的评价。结果后凸畸形术后矫正度数较术前两组均很明显。随访中,A组矫正度数的丢失明显小于B组(P=0.0001)。术后伤椎前缘高度百分比增加值两组比较有显著差异(P<0.001)。术后随访中,A组伤椎椎体前缘高度无丢失(P<0.001),B组伤椎椎体前缘高度有丢失(P<0.05)。采用Denis疼痛分级,两组术后均有很好的改善。采用Frankel功能分级,术后神经功能变化,A组患者平均提高优于B组。结论脊柱后路颗粒骨经椎弓根椎体内外植骨结合内固定治疗胸腰椎骨折植骨融合率高,能有效恢复椎体高度和防止术后矫正度丢失。     

Incorporation of impacted morselized bone allografts in rabbits

Morselized bone allografts have been used for the treatment of bone stock loss in orthopedic revision surgery with encouraging results. However, several parameters can influence the graft incorporation including the processing treatments. This experimental work used a cavitary bone defect in 90 rabbits to evaluate the sequence of incorporation of three different kinds of morselized bone allografts: uncryopreserved cancellous bone, freeze-dried cancellous bone, and totally demineralized cortical bone each of which were prepared in accordance with our rigid protocol. Revascularization and remodeling of the transplanted bone grafts were evident upon histological evaluation. Bone apposition and bone resorption resulted in a mixture of graft and new bone. Mineralized cancellous grafts showed great osteoconductive capacity, whereas demineralized cortical grafts showed an intense osteoinductive capacity and a weak osteoconductive capacity. In a general evaluation, cryopreserved cancellous bone grafts showed superior biological efficacy for reconstruction of experimental bone defects, closely followed by freeze-dried cancellous bone grafts, and, finally, by demineralized cortical bone grafts. These results validate our protocol for the processing and preservation of these three kinds of bone grafts.     

Alternative materials to acrylic bone cement for delivery of depot antibiotics in orthopaedic infections

Acrylic bone cement has considerable laboratory and clinical data validating it as a delivery material for depot administration of antibiotics. However, an alternate material that does not require a secondary procedure for removal is desired. Many biodegradable materials have been evaluated as alternatives including protein-based materials (collagen, fibrin, thrombin, clotted blood), bone-graft, bone-graft substitutes and extenders (hydroxyapatite, beta-tricalcium phosphate, calcium sulfate, bioglass), and synthetic polymers (polyhanhydride, polylactide, polyglycolide, polyhydroxybutyrate-co-hydroxyvalerate, polyhydroxyalkanoate). Various forms and combinations of these materials have been investigated worldwide, characterizing their elution properties and performance in treating osteomyelitis in animal models. Many of these have had limited clinical evaluation. Outside the United States, some of these materials are used clinically. In the United States, none have been approved. None are commercially available for clinical use. Morselized cancellous bone and calcium sulfate are the two materials that have been used clinically in the United States on a physician-prescribed, hand-mixed, basis. Considering the limited clinical data that currently are available, the use of these materials still is experimental. Clinical application should be cautious, limiting the total antibiotic load. Until definitive data are available, a prudent dose would be no higher than one that would have acceptable toxicity risk if administered intravenously over 24 hours.     

Fibrous tissue armoring increases the mechanical strength of an impacted bone graft

Impacted, morselized bone allografts are used with good clinical results in revision of hip prostheses with loosening and osteolysis. The impacted bone graft appears radiographically to remodel, but histological analyses have shown a heterogeneous picture with a mixture of living and dead bone. Thus, complete remodeling of the graft may be neither a prerequisite nor a cause of the good clinical results. The present study concerns the mechanical effect of the mere armoring of the bone graft by ingrowing fibrous tissue. We compared the compression strength of freshly-impacted grafts to grafts that had been inserted into a bone chamber and thus were penetrated by fibrous tissue growing in between the graft trabeculae. The compressive strength was doubled after 4 weeks of fibrous ingrowth. We conclude that the mechanical properties of an impacted graft are enhanced by armoring with ingrowing fibrous tissue. Strengthening of the parts of the impacted grafts which have not yet remodeled, would be clinically relevant for the outcome of the operation, since these parts are at high stress during the whole remodeling period. Complete osseous remodeling may not be necessary to obtain a good clinical result with a morselized impacted graft.