组织工程化同种异体骨移植修复骨缺损

目的解决骨缺损修复时自体骨移植存在修复材料来源有限,异体骨移植又为爬行替代,存在愈合慢、假关节率高的问题。方法以兔骨膜成骨细胞为种子细胞,经分离、体外培养、传代,再粘附于冷冻干燥表面脱钙同种异体骨,共同复合培养,制作兔胫骨缺损,分异体骨移植组(对照组)、组织工程化异体骨移植组,术后2、4、6周各处死2只兔子,大体观测骨痂大小及硬度;苏木精-伊红染色,光镜观察细胞在材料上的生长情况,了解其愈合快慢及质量。结果与对照组比较,实验组炎性明显较轻,细胞生长活跃,缺损愈合快。结论组织工程化同种异体骨移植能解决骨缺损修复时自体植骨材料来源有限,特别是在小儿及骨缺损大时修复材料的来源问题;同时,植入的异体骨又具有支架及自体成骨细胞活性,使植入的异体骨愈合加快,克服其愈合慢、假关节率高的问题。     

以生物衍生材料为支架的组织工程骨移植早期兔外周血T淋巴细胞亚群的变化

目的检测体外构建的组织工程骨移植后兔外周血T细胞亚群的变化，对移植组织进行组织学观察，探讨以生物衍生材料作为骨组织工程支架材料的可行性。方法组织工程骨以兔骨膜来源的成骨细胞为种子细胞，经抗原自消化、部分脱钙、冻干后的异体骨为支架材料于体外构建。将健康新西兰白兔48只制成1cm长桡骨缺损模型后，随机分成A～D4组，每组12只，分别用部分脱钙冻干骨（partial demineralized freeze—dried bone，PDFDB）、组织工程骨、自体骨、同种异体骨植入兔桡骨节段性缺损。术后1、2、4周取材，用流式细胞仪检测4种材料移植早期兔外周血T淋巴细胞亚群的变化；通过常规组织学检测观察2、4、8、12周时4种材料的成骨作用。结果B组术后2周材料孔隙内有成骨细胞和成软骨细胞，可见骨、软骨混合性新生物形成，周边分布有破骨细胞，部分网架呈蚕食状被破坏吸收。术后4周，形成的新生骨过渡为编织骨。A、B组材料植入后1、2周外周血CD4^＋和CD8^＋T细胞较术前明显升高（P〈0．05）；术后4周CD4^＋T细胞较术前轻度偏高，但无统计学差异（P〉0．05）。C组术后CD4^＋和CD8^＋T细胞升高不明显（P〉0．05）。D组术后1、2、4周外周血CD4^＋和CD8^＋T细胞较术前及其他各组同期均明显增高（P〈.．05）。结论PDFDB为支架材料构建的细胞一材料复合物移植后外周血T淋巴细胞增高，但不影响其良好的修复骨缺损能力，生物衍生骨可作为支架材料应用于骨组织工程研究。     

预构骨肌皮瓣修复下颌骨和皮肤复合缺损的实验研究

目的 探讨BMP-2与胶原复合材料在骨骼肌中异位成骨预构骨肌皮瓣,修复自体下颌骨和皮肤复合缺损的可行性. 方法 4～6周龄新西兰白兔24只,体重2.0～2.5 kg,雌雄不拘,随机分成3组,即实验组、对照组和空白组(n=8).将BMP-2与胶原复合,植入兔背阔肌,预构异位新生骨组织,2、4、6周后行X线片、ALP、Von Kossa、CD31免疫组织化学血管标记及组织学观察.6周后,实验组动物于同侧下颌骨体部制备2 cm × 3 cm皮肤缺损,并形成直径8 mm洞穿性骨缺损;以同侧胸背动脉体表投影为皮瓣纵轴,设计含预制新骨组织的背阔肌肌皮瓣,带蒂移位修复下颌骨及皮肤复合缺损.对照组和空白组实验动物下颌骨体部均造成直径8 mm的洞穿性骨缺损,对照组将复合组织瓣中的骨性部分游离移植修复缺损;空白组缺损不予修复.术后6周,各组取材行四环素荧光染色、X线摄片、组织学观察以及新骨计量等,观察骨和皮肤复合缺损修复效果. 结果 BMP-2与胶原复合材料在兔背阔肌中4～6周成骨,胶原材料于植入后3～5周降解,成骨过程以软骨成骨为主,新骨形态为编织骨,可见明显的微血管分布.修复自体下颌骨缺损6周后,实验组皮肤及骨缺损均愈合良好,对照组缺损修复区基本骨化,空白组尚残留大块骨缺损实验组、对照组及空白组新骨计量分别为(1.594 ±0.674)、(0.801 ±0.036)和(0.079±0.010)mm2,组间两两比较,差异均有统计学意义(P＜0.05). 结论 预构的骨肌皮瓣带血管蒂移位修复兔自体下颌骨和皮肤复合缺损具有可行性和明显优势,有望成为一种血管化骨移植的供区预构形式.     

同种异体脂肪干细胞复合脱钙骨修复大鼠尺骨缺损

目的探讨同种异体脂肪干细胞修复管状骨缺损的可行性。方法获取SD大鼠的腹股沟处脂肪,分离培养脂肪干细胞（Adipose-Derived Stem Cells,ADSCs）;鼠第3代ADSCs与脱钙骨复合,24 h后进行成骨诱导培养。检测细胞在材料表面的生长及成骨分化能力。建立鼠两侧尺骨缺损模型,分别植入鼠ADSCs-脱钙骨复合物（实验侧）和单纯脱钙骨材料（对照侧）;8周、24周后取样,行DR和组织学检测,观察成骨情况。结果 ADSCs能在脱钙骨上很好地黏附和生长,并维持成骨分化能力。细胞-材料复合物植入24周后,DR显示实验侧有新生骨基质长成,对照侧未见骨组织生成。组织学检测显示,实验侧缺损区被典型的骨组织取代,可见新生骨小梁附着于脱钙骨表面;对照侧只有少量的骨组织和纤维组织充填。结论 ADSCs-脱钙骨材料复合物植入,能成功修复临界大小的管状骨缺损。     

骨髓基质成骨细胞-松质骨基质复合人工骨修复颅骨缺损的实验研究

目的 观察松质骨基质－骨髓基质成骨细胞复合工人骨在骨缺损区的成骨作用，探索该组织工程化人工骨修复颅骨缺损的可行性。方法 成年新西兰兔骨髓细胞体外培养、诱导后，接种于藻酸盐－松质骨基质中，形成松质骨基质－藻酸盐－骨髓基质成骨细胞复合人工骨，修复自体颅骨缺损。分别植入松质骨基质和骨髓基质成骨细胞作为对照。植入4周和8周后行X线摄片和组织学检查，观察骨形成情况。结果 复合人工成骨量优于单纯植入松质骨基持或骨髓基质成骨细胞组，并明显优于空白对照。结论 松质骨基质－骨髓基质成骨细胞复合人工骨髓修复颅骨缺损效果良好，可以作为临床大型骨缺损修复的途径之一。     

Repair of bone defect with vascularized tissue engineered bone graft seeded with mesenchymal stem cells in rabbits

This study evaluated the results of repair of the radius defect with a vascularized tissue engineered bone graft composed by implanting mesenchymal stem cells (MSCs) and a vascular bundle into the xenogeneic deproteinized cancellous bone (XDCB) scaffold in a rabbit model. Sixty-four rabbits were used in the study. Among them, four rabbits were used as the MSCs donor. Other 57 rabbits were divided into five groups. In group one (n = 9), a 1.5 cm bone defect was created with no repair. In group two (n = 12), the bone defect was repaired by a XDCB graft alone. In group three (n = 12), the defect was repaired by a XDCB graft that included a vascular bundle. In group four (n = 12), the defect was repaired by a XDCB graft seeded with MSCs. In group five (n = 12), the defect was repaired by a XDCB graft including a vascular bundle and MSCs implantation. The rest three rabbits were used as the normal control for the biomechanical test. The results of X-ray and histology at postoperative intervals (4, 8, and 12 weeks) and biomechanical examinations at 12 weeks showed that combining MSCs and a vascular bundle implantation resulted in promoting vascularization and osteogenesis in the XDCB graft, and improving new bone formation and mechanical property in repair of radius defect with this tissue engineered bone graft. These findings suggested that the vascularized tissue engineered bone graft may be a valuable alternative for repair of large bone defect and deserves further investigations.     

自身骨泥成骨活性的实验研究

目的：观察长管状骨钻孔产生的骨泥的成骨活性。方法：选健康家兔２２只,桡骨中段连续钻孔采集骨泥,植入兔股四头肌。２周取５只兔做ＥＣＴ检查,１、２、３周分别做组织学检查、Ｅｌｉｖｉｓｉｏｎ二步法免疫组化染色及碱性磷酸酶测定。结果：自身骨泥具有良好的异位诱导成骨活性。植入区放射性浓聚程度明显高于对侧正常组织（Ｐ＜００５）。植入１周软骨生成,３周网织骨形成。组织碱性磷酸酶活性明显高于正常肌肉（Ｐ＜００１）,免疫组化发现细胞及组织ＢＭＰ强阳性。结论：长管状骨钻孔产生的自身骨泥具有诱导成骨作用,可做为需少量植骨的植骨材料。     

成人骨髓源成骨细胞体内异位成骨的实验研究

目的　观察成人骨髓源成骨细胞与珊瑚羟基磷灰石 (CHA)复合构建的组织工程化骨组织的体内异位成骨能力 ,探讨适宜的组织工程化骨组织的构建方式。　方法　抽取健康成人骨髓 ,采用全骨髓法培养 ,使成人骨髓基质干细胞 (hBMSCs)定向诱导分化为成骨细胞 ,然后种植于CHA上 ,复合培养 5d后植入裸鼠股部肌袋内 ,以未种植细胞的CHA作为对照。术后 4,8,12周取材作一般观察、X线摄片、组织学检查和源于成人的碱性磷酸酶 (ALP)及骨钙素 (OCN)的RT PCR检测。　结果　原代和传代培养的细胞具有活跃的增殖能力 ,成骨细胞与CHA复合生长良好。实验组术后 4、8、12周均有新骨形成 ,随着时间延长 ,新骨生成量增多 ;对照组则均无新骨形成。术后 4周实验组RT PCR检测源于人的ALP及OCN表达均为阳性 ,对照组阴性。　结论　成人骨髓源成骨细胞与CHA复合培养后构建的组织工程化骨组织 ,具有良好的异位成骨能力 ,可望应用于临床修复骨缺损。     

骨髓基质干细胞与生物衍生骨复合修复山羊胫骨缺损的影像学研究

目的探讨骨髓基质干细胞(MSCs)与生物衍生骨复合修复山羊胫骨的长段骨-骨膜缺损,以及修复负重骨缺损的可行性. 方法将18只12月龄健康杂种青山羊(雌雄不限),制备成双侧胫骨中段20 mm骨-骨膜缺损模型,常规钢板螺钉固定;MSCs与生物衍生骨于体外复合培养;对同一只山羊将复合物植入右侧胫骨缺损处作为实验组,以单纯材料植入左侧胫骨缺损处作为对照组,空白组不植入任何材料;在8、12、16和24周各时间点分别行标本的大体观察、X线片观察和骨密度测试,比较其修复骨缺损的能力. 结果大体观察、X线片和骨密度测试显示:实验组8周骨缺损部分修复,12、16周骨缺损完全修复,8、12和16周其骨密度较对照组高,差异有统计学意义(P＜0.05);24周实验组与对照组骨密度差异无统计学意义;空白组骨缺损未修复. 结论组织工程骨早期修复骨缺损能力较强,且较单纯材料成骨量大、迅速,能够对负重骨缺损进行有效的修复.     

珍珠层聚乳酸人工骨复合成骨细胞体内异位成骨研究

目的探讨珍珠层聚乳酸(nacre／polylactic acid，N／P)人工骨与同种异体成骨细胞复合，植入体内后异位成骨的作用机制，以及作为骨组织工程支架材料的可行性。方法成年雄性新西兰大白兔18只，按2、4和8周3个时间点随机分成3组，每组6只。将体外培养的同种异体新西兰大白兔成骨细胞，种植到N／P人工骨材料上，并植入每只兔左侧背部皮下为实验组；以不复合成骨细胞的N／P人工骨材料植入右侧背部皮下作对照，分别于植入后不同时间点取材，经大体观察、组织学检查和免疫组织化学方法检测。结果实验组2周时材料周围有少许炎性细胞聚集，4周时有类骨质形成，8周时有成熟骨组织形成，其中可见骨髓腔；对照组2、4周时仅见大量纤维组织长入材料内，8周时材料内纤维组织增多，但无成骨发生。结论N／P人工骨可作为理想的骨组织工程支架材料。     

自体颅骨粉末修复颅骨缺损的实验研究

目的 建立兔自体颅骨粉末移植修复颅骨缺损的动物模型,进行相关基础问题的研究,以更好地指导自体颅骨粉末移植修复颅骨缺损的临床工作.方法 新西兰大白兔30只,每只大白兔的顶部人工形成3个直径为1 cm颅骨全层缺损孔A、B、C.孔A为对照组;孔B、C作为实验组移植人工形成缺损时收集的骨粉,其中孔B在移植的骨粉上下面放置生物膜.术后4、8、12周各处死10只动物并取材分析.结果 孔A大部分由纤维结缔组织修复.孔 B早期就能迅速地以松质骨完全修复整个缺损,但松质骨后期的生长、改建、成熟过程比较缓慢.孔C新生骨更成熟,骨性修复慢且不完全.移植的骨粉被逐步吸收.早期新骨形成区可见大量的毛细血管分布.同一缺损,术后12周与术后4、8周形成的新骨钙含量差异有统计学意义(P＜0.05),同一时期,术后8、12周孔C形成的新骨钙含量比孔B的高,差异有统计学意义(P＜0.05).结论 新生骨的形成与血管的增生在时间和空间上有着密切的关系.生物膜可以促进移植的骨粉早期迅速形成初级松质骨.     

An evaluation of human demineralized bone matrices in a rat femoral defect model

The osteoconductive and osteoinductive potential of two human allogeneic demineralized bone matrix putties were compared in a critical-sized athymic rat femoral defect model. Defects were treated with (1) a demineralized bone matrix in a hyaluronic acid carrier, (2) a demineralized bone matrix in a glycerol carrier, (3) a hyaluronic acid carrier alone, or (4) with no implant. Radiographic examinations and histologic analyses were done at 4, 8, and 16 weeks postoperatively. Eight of the 48 defects treated with a demineralized bone matrix and none of the 36 surgical controls showed complete radiographic healing by 16 weeks and no statistically significant difference between the radiographic scores for the two demineralized bone matrix preparations was found. On histologic review, both preparations of demineralized bone matrix had passive remineralization. The largest foci of endochondral ossification were seen in limbs treated with a demineralized bone matrix in a hyaluronic acid carrier. The 8-mm rat femoral defect allows for stringent assessment of the osteoinductive potential of bone graft substitutes. Hyaluronic acid and glycerol are viable carriers for demineralized bone matrices. As both de-mineralized bone matrices tested provided an adequate osteoconductive matrix and showed some, although limited, osteoinductive capacity, these materials should be used in clinical practice only as bone graft extenders or enhancers.     

异体软骨痂移植的初步结果

目的 通过观察异体软骨痂移植后的生物学过程判断其作为植骨材料的可行性。方法 将1只SD大鼠的双侧股骨干造成闭合骨折,1周时切开获取软骨痂,－196℃冻存2周后移植于5只SD大鼠的左侧胫骨干部分缺损区（此骨缺损模型的成骨活动只表现为膜内化骨的方式）,右侧植入异体松质骨作为对照组。将取材标本制成不脱钙切片,经亮绿和藏红T染色。结果 术后1周取材1例,缺损区实验侧和对照侧均未见有软骨组织和骨组织形成。术后2周处死其余4只大鼠,实验侧（3／4）可见有软骨组织和骨组织形成。骨组织内已有髓腔形成,骨组织周围是软骨组织,与宿主骨之间有纤维组织相隔。结论 异体软骨痂移植后未被吸收,可经软骨内化骨的方式产生骨组织,为软骨痂作为植骨材料的进一步研究和开发提供了初步依据。     

基因修饰的组织工程骨联合带血管蒂骨膜移植修复长段骨缺损的研究

目的评价骨形态发生蛋白2（bone morphogenetic protein2,BMP-2）基因修饰的组织工程骨联合带血管蒂骨膜移植修复长段骨缺损的效果。方法分离培养兔骨髓基质干细胞,经BMP-2基因转染后复合异种骨支架体外构建基因修饰的组织工程骨（gene modified tissue engineering bone,GMB）。建立兔双侧桡骨缺损（长2.5cm）模型,采用5种方法修复。A组：GMB＋带血管蒂骨膜移植;B组：GMB＋血管束植入;C组：GMB＋游离骨膜移植;D组：GMB;E组：单纯支架。于术后第4、8、12周行X线、组织学、生物力学测定和微血管墨汁灌注等观察血管形成及成骨情况。结果①A组血运建立快,第8周时即可修复骨缺损,其修复机制包括膜内成骨和软骨成骨两种机制;②B组血管束发出分支向移植骨内长入,但中心区成骨缓慢,第12周时骨缺损得到完全修复;③C组第4周时游离骨膜成活并发出微小血管,第8周时形成薄层外骨痂,第12周时骨缺损基本修复;④D组在BMP-2基因诱导下成骨速度和质量优于E组,可在第12周时使骨缺损部分修复,但中心区呈＂空心＂现象;而E组第12周时形成骨不连,缺损区内被纤维组织填充。结论带血管蒂骨膜与BMP-2基因修饰的组织工程骨联合移植,既提供了血运又提供了骨膜成骨细胞,同时具有良好的骨生成、骨诱导和骨引导作用,是治疗节段性骨缺损较为理想的方法。     

Osteogenetic activity in composite grafts of demineralized compact bone and marrow

The effects of a composite graft of autologous marrow and demineralized autologous compact bone on the healing of a surgically created bone defect were observed in adult rabbits. A segment of the radius was bilaterally resected, demineralized, and replaced. On one side the bone graft was supplemented with autologous marrow. The new bone formation was measured 14 and 28 days after operation by roentgenography, including planimetry with scintigraphy and autoradiography using 99mTc-labelled MDP. The composite graft, i.e., demineralized compact bone and marrow, had a significantly higher (p less than 0.01) bone formation rate 14 days after operation compared with the graft with demineralized compact bone in the opposite radius. At 28 days, however, there were no differences between the sides. Viable autologous marrow cells and demineralized autologous compact bone graft accelerate the rate of osteogenesis, but only at the beginning of the healing process.     

Demineralized bone implants

There are three mechanisms of bone formation that underlie the use of the different types of implants. In osteogenesis, viable osteoblasts and preosteoblasts are transplanted from one part of the body to the site where new bone is needed; cancellous marrow grafts are an example of such osteogenic engraftment. In osteoconduction, the implant does not provide many viable cells but rather acts as a scaffolding for the ingrowth of new bone from the margins of the defect with the concurrent resorption of the implant; cortical bone grafts or banked bone segments are examples of this "creeping substitution." In osteoinduction, the implant stimulates the transformation of connective tissue to produce endochondral bone, even in extraskeletal sites; demineralized bone implants promote bone formation by osteoinduction. The physiology, cell biology, biochemistry, and endocrinologic regulation of induced osteogenesis are areas of active investigation. Fresh autogenous cancellous bone grafts are preferred for non-stress-bearing defects, but are often of limited availability for extensive procedures, especially in infants. Demineralized bone implants have been used successfully in certain types of craniomaxillofacial, orthopedic, periodontal, and hand reconstruction. Tissue transformation may become as important to reconstructive surgery as is tissue transplantation.     

Reconstruction of caprine mandibular segmental defect by tissue engineered bone reinforced by titanium reticulum

Objective: To investigate the feasibility of using natural poritos as scaffolds in bone tissue engineering (TE) and repair of caprine mandibular segmental defect with titanium reticulum reinforced. Methods: Natural poritos with a pore of 190-230 μn in size and porosity of about 50% -65% was molded into the shape of granules 5 mm×5 mm×5 mm in size. Expanded autologous caprine marrow mesenchymal stem cells were induced by recombinant human morphogenetic protein-2 ( rhBMP2 ) to improve osteoblastic phenotype. Then marrow derived osteoblasts were seeded into poritos in density of 4×107/ml and incubated in vitro for 48 hours prior to implantation. Then osteoblastic cells/poritos complexes were implanted into mandibular defect and the defect was reinforced by titanium reticulum. Implantation of poritos alone acted as the control. Bone regeneration was assessed 4, 8, 16 weeks after implantation using roentgenographic analysis and histological observation was done after 16 weeks. Results: New bone could be observed histologically on the surface and in the pores of natural coral in all specimens in the cell-seeding group, whereas in the control group there was no evidence of osteogenesis process in the center of the construction. The results showed that new bone grafts were successfully restored 16 weeks after implantation. Conclusions: This study suggests the feasibility of using porous coral as scaffold material transplanted with marrow derived osteoblasts by TE method. By means of titanium reticulum reinforcement, mandibular defect could be successfully restored. It shows the potentiality of using this method for the reconstruction of bone defect in clinic.     

自体微小颗粒骨复合骨形成蛋白修复兔桡骨缺损

目的探讨自体微小颗粒骨复合I型胶原以及骨形成蛋白(bone morphogenetic protein，BMP)移植修复节段性兔桡骨缺损的效果。方法新西兰大耳白兔56只，切取自体髂骨研磨成微小颗粒，分别与BMP及I型胶原复合，实验分成4组（n=16)。A组：自体微小颗粒骨复合BMP、I型胶原，B组：自体微小颗粒骨复合I型胶原，C组：自体微小颗粒骨，用于修复兔桡骨干1．5cm缺损的动物模型。D组：空白对照组(n=8)，双侧桡骨缺损不作处理。术后2、4、8和12周，行X线片、组织学观察，骨密度及生物力学检测，比较各移植物修复节段性骨缺损的疗效。结果X线片显示，A组术后8周即可使骨缺损完全修复，而B组术后12周使骨缺损完全修复。术后8、12周骨量测定A组成骨量最多，12周生物力学测定显示移植物修复后的骨缺损具有最佳生物力学表现，而C组则不能完全修复骨缺损。结论自体微小颗粒骨复合BMP、I型胶原及自体微小颗粒骨复合I型胶原均能有效修复节段性骨缺损，以复合BMP移植效果更理想。     

脱钙冻干骨修复种植周骨缺损的扫描电镜观察

目的比较脱钙冻干骨(DFDB)、脱钙冻干骨复合人重组骨形成蛋白-2(rhBMP-2)、脱钙冻干骨联合钛膜的骨修复能力。方法 3条犬股骨种植体周形成4 mm×3 mm×3 mm的骨缺损,分别植入上述3种不同材料。术后4、8、12周分期处死动物,取含种植体的骨段进行扫描电镜观察,观察新骨形成情况及其与种植体之间的缝隙。结果 DFDB可单独用于修复种植体周骨缺损,但成骨作用较慢;DFDB+rhBMP-2和DFDB+钛膜能较早诱导新骨形成,加速骨整合过程。结论DFDB是一种较理想的骨修复材料,复合rhBMP-2或与钛膜联用时效果更佳。     

三种生物骨衍生材料修复节段性骨缺损的实验研究

目的　评价 3种生物骨衍生材料修复节段性骨缺损的成骨作用。　方法　将 6 0只健康日本大耳白兔双侧桡骨中段制成 10 mm节段性骨缺损 ,并随机分为 A、B、C、D和 E组 ,每组 12只 ,其中 A组植入复合型完全脱蛋白骨 (composite fully deproteinised bone,CFDB)、B组植入部分脱蛋白骨 (partially deproteinised bone,PDPB)、C组植入部分脱钙骨 (partially decalcified bone,PDCB)修复兔桡骨节段性缺损 ,D组自体髂骨移植 ,E组以空白缺损为对照 ,于术后4、8、12及 2 4周取材 ,通过 X线摄片和不脱钙硬组织切片检测 ,评价 3种材料的成骨作用。　结果　 X线摄片观察 :A、B与 C组 4周时材料密度较高 ;8周时材料与宿主骨交界处模糊 ;12周时材料边缘部分区域密度接近宿主骨 ;2 4周时 B组髓腔再通 ,C组缺损区域密度大部分接近宿主骨 ,有少许高密度影 ,A组缺损区域有较多高密度影。 X线片评分 4周和8周时各材料组无统计学差异 (P>0 .0 5 ) ;12周时 B组和 C组高于 A组 (P<0 .0 5 ) ;2 4周时 D组 >B组 >C组 >A组(P<0 .0 5 )。经组织学形态观察可见 4周和 8周时新骨贴附材料生长 ;以后新骨增多 ;材料随着时间的推移逐渐降解吸收 ;2 4周时成骨量 D组 >B组 >C组 >A组 (P<0 .0 5 )。　结论　 PDPB修复节段性骨缺损的效果佳 ,