牵张成骨术在延长下颌骨中新骨生成方式的研究

目的　探讨山羊下颌骨牵张成骨过程中新骨生成方式及其影响因素。方法　用口外牵张器 ,按1mm/天的牵张速率将 12只成年山羊的双侧下颌骨延长 10 m m,牵张结束后固定至第 2、4和 8周分别处死 4只动物 ,拍摄下颌骨 X线片后取牵张区新生骨痂作组织学观察。结果　牵张间隙内新骨组织沿牵张方向向心性生长 ,成骨方式主要是膜内成骨 ,在牵张器松动的标本早期仍可观察到散在的软骨岛。结论　牵张延长下颌骨过程中新骨生成方式主要为膜内成骨 ,软骨化骨只是在牵张器固定不良时发生。     

关节－干骺端软骨细胞移植修复兔桡骨缺损

目的研究组织工程软骨移植于成年兔桡骨缺损后的生长、分化与转归特点,以及引导性骨再生和骨缺损的修复机制。方法取自一日龄新生兔关节－干骺端复合物的软骨细胞在几丁质纤维网中增殖21d后装入硅胶管内,套接在成年兔桡骨干1cm的缺损处（实验组12只）;对照组10只在缺损处套接空硅胶管,2只仅填入裸几丁质纤维。术后4周两组各处死3只动物取材,其余在术后16周取材。结果实验组术后4周3只动物的工程软骨组织在骨缺损内形成软骨样组织,术后16周9只动物中有2只动物的缺损愈合。对照组术后4周已开始骨愈合,术后16周9只动物的骨缺损全部愈合。结论新生兔关节－干骺端复合物的软骨细胞在成年兔桡骨缺损区（套管内）未肥大钙化,未再现软骨内化骨过程。缺损内的工程软骨可能因占据空间、阻碍成骨成分进入而中断了骨缺损修复过程。引导性骨再生的机制可能是人工膜管加强了骨膜的天然引导作用而促进了骨愈合。     

培养软骨对胫骨生长影响的实验研究

目的 :探讨培养软骨植入胫骨干骺端缺损后的组织学改变 ,以及对胫骨生长的影响。方法 :自 3周龄兔关节面分离软骨细胞 ,经离心管培养 2周形成软骨。于 1 6只 1 2周龄新西兰兔右侧胫骨近端生长板下方 1 .5mm处造成边缘性缺损 ,移植培养软骨。左侧胫骨未作手术为正常对照。分别于术后 6、1 2周进行X线摄片和组织学检查。结果 :6周时胫骨近端生长板变窄 ,其下方 6mm处形成薄层软骨或不规则软骨块 ,缺乏生长板柱状细胞排列结构。大量新骨形成和植入区皮质骨增厚。 1 2周时生长板基本闭合 ,干骺端结构正常 ,无软骨。双下肢X线摄片显示双侧胫骨生长无差异 (P >0 .0 5)。结论 :培养软骨植入干骺端可以维持组织性质 ,但不具有生长板结构和生长能力     

骨质疏松性骨折膜内成骨和软骨内成骨特点的定量研究

目的通过去势大鼠骨折模型,探讨骨质疏松性骨折愈合过程中膜内成骨和软骨内成骨的特点。方法57只6月龄雌性SD大鼠,随机分为卵巢切除组(OVX)和对照组(SHAM),术后3个月pQCT随访观察到OVX组的骨密度(BMD)显著下降。随后OVX组和SHAM组均构建闭合性股骨骨折模型,每周摄X线片随访骨折愈合情况并行骨痂定量分析。第2、4、8周取材,行显微CT(micro-CT)三维骨痂定量分析和组织学分析,并于第8周采集标本进行生物力学测试。结果SHAM组膜内成骨的新生骨量在骨折愈合早期显著高于OVX组(P=0.031),骨折区域的软骨形成也较OVX组活跃,但未构成显著性差异。随着软骨内骨化的进行,SHAM组软骨内成骨区域的新生骨量显著高于OVX组(P=0.023)。骨折后8周时,SHAM组骨折愈合率高于OVX组,生物力学强度也明显优于OVX组(P=0.044)。结论骨质疏松对骨折愈合中膜内成骨和软骨内成骨的过程均产生负性作用,其分子生物学机制有待进一步探讨。     

兔下颌骨牵拉成骨动物模型的建立及初步观察

目的　建立兔下颌骨牵拉成骨动物模型,研究了解颅面部牵拉骨生成的规律。方法　将12 只新西兰大白兔右侧下颌骨第一磨牙前完全截骨后用牵拉器固定,左侧不做手术为对照侧。1周后以每天一次0.9 m m 的速度逐步牵拉,连续10 天。牵拉完成后1 天,2、4 和8 周每组处死3只兔,取下完整下颌骨进行大体测量,X线摄片,新骨组织学观察。结果　12只兔右侧下颌骨平均延长8.3 m m ,与对照侧比较有显著性差异(P< 0.01),无骨不连及畸形愈合。X线摄片发现,延长完成后2周牵拉间隙已被骨痂桥接,8 周时,X线片上很难分辨新骨和正常骨。组织学观察牵拉早期即有胶原束形成,随后钙化成骨,未发现软骨中介体。结论　运用牵拉成骨技术可成功地延长兔下颌骨,无骨不连和畸形愈合等并发症,新骨以膜内成骨方式生成     

胫骨远近端骨膜外截骨延长修复胫骨缺损的临床X线研究

目的 探讨应用环形外固定架对胫骨远近干骺端进行骨膜外截骨延长成骨的临床影像学研究.方法 收集临床治疗的44例患者并分为两组,A组经胫骨近干骺端骨膜外截骨延长,B组经胫骨远干骺端骨膜外截骨延长,术后第7天开始延长外固定架,分别于不同时段拍摄X线片观察延长区成骨,比较两组间的差异.运用Enneking系统对两组下肢功能进行评分比较,比较两组间的差异.结果 术后随访6个月～2年,在X线片上观察胫骨近干骺端截骨延长较远干骺端截骨延长早期有更为明显的成骨现象,随着时间推移,牵张间隙新生骨密度影像也由低向高增加,两组差异性逐渐减小.下肢功能两组无统计学差异.结论 环形外固定架胫骨近干骺端骨膜外截骨延长有利于早期活跃性成骨作用.     

家兔自体骨髓移植对骨痂中钙镁铜含量的影响

目的 探讨新骨的形成在骨髓移植术后2周尤为显著现象的机制。方法 用34只家兔剥除双侧桡骨骨膜3cm，截除剥离骨膜后的桡骨中段1cm，1小时后去除骨缺损区血肿，从股骨大转子处抽取1ml骨髓，随机注入一侧桡骨缺损区作为实侧，另一侧注入等量生理盐水作为对照侧，术后2、4、6、8周分批做放射学、组织学和骨痂中钙、镁、铜含量的检查。结果 骨髓移植有肯定的成骨效果，术后2周实验侧骨痂中镁、铜及术后4周镁含量高于对照侧（P＜0．01）。结论 铜和镁在骨髓移植促进骨缺损愈合早期可能具有重要作用，移植术后的2周内补充铜和镁有可能提高骨髓移植的成骨能力。     

局部应用重组人碱性成纤维细胞生长因子对牵开骨痂影响的研究

目的评价在骨延长区坚实化期局部应用重组人碱性成纤维细胞生长因子（rh-bFGF）对牵开骨痂的影响。方法对30只成年犬单侧胫骨中段横断截骨后，应用Ilizarov环形外固定架以1mm／d的速度，每天延长1次的频率延长，建立14mm的牵开间隙。在延长期末通过手术切开的方式于延长区域中央植入不同的材料。根据植入物的不同将动物等分成三组，A组（空白对照组）：进行假手术；B组（阴性对照组）：植入不含生长因子的胶原海绵；C组（实验组）：植入含rh-bFGF 400μg的胶原海绵。于第二次手术后即刻、2周、4周和8周时分别摄普通X线片，测量骨密度和行不脱钙组织学检查。结果x线片上A组至8周时仍未出现连续的骨痂，B组和c组分别在8周和4周时有骨痂连接截骨断端。重复测量的方差分析表明延长区分组因素差异有统计学意义，而其它区域无差异。单因素方差分析表明延长区在术后即刻组间无差异，第2、4、8周时A组和B组间任何时刻差异无统计学意义，C组分别是A组的1．62、1．60和1．5l倍，差异有统计学意义（P值分别为0．005、0．006和0．004）。在第2,4周时c组分别是B组的1．38和1．44倍，差异有统计学意义（P值分别为0．03和0．02）。组织学上牵开间隙内同时存在膜内化骨和软骨内化骨的过程，实验组愈合和塑形均比对照组提前。结论在成年犬骨延长模型局部应用rh-bFGF能够促进牵开区骨组织的再生、钙化和塑形，缩短坚实化的时间。     

脱蛋白骨复合骨形态发生蛋白对前交叉韧带重建术后腱-骨愈合的影响

目的 探讨兔异体脱蛋白松质骨(DPB)复合骨形态发生蛋白(BMP)对前交叉韧带(ACL)重建术后腱-骨愈合的影响. 方法取96只成年新西兰大白兔,分为四组,每组24只:DPB+BMP组、DPB组、BMP组及空白对照组,分别用自体半腱肌腱进行膝关节ACL重建,DPB+BMP组在股骨隧道内植入DPB-BMP复合体,DPB组和BMP组分别在股骨隧道内植入DPB、BMP,空白对照组的骨隧道内不植入其他材料.于术后2、4、6、8周时分别处死各组中的6只动物,切取骨隧道内标本,通过大体观察及组织学观察分析腱-骨愈合进程. 结果术后2周时BMP+DBP组的骨隧道内新骨生成活跃,肌腱周围出现较多纤维软骨组织;4周时骨隧道内出现钙化的纤维软骨,肌腱末端与钙化软骨融合为一体,并见Sharpey's纤维形成;6周时隧道内出现了更多的钙化软骨,肌腱与骨的结合区出现潮线,具有正常ACL止点的结构特点;8周时肌腱与骨的连接更加成熟,钙化软骨增多.其他三组的腱-骨愈合过程均迟于DPB+BMP组.结论 DPB复合BMP能促进ACL重建术后的腱-骨愈合.     

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。     

体外冲击波对兔长骨牵伸骨痂形成的早期作用

目的观察体外冲击波对兔长骨牵伸骨痂形成的早期作用,探讨其作用机制。方法30只成年新西兰大白兔胫骨中段截断,5d后开始延长,每天延长1mm,10d后停止延长,待骨痂形成10d;随机分成实验组和对照组,实验组于牵伸骨痂中心区进行体外冲击波(ESW)处理,冲击波能量密度0.54mJ/mm2,脉冲1000次;对照组不予任何处理。两组于截骨后45、60、75d取材,采用X线片、骨密度检测对牵伸骨痂形成进行观察,并行统计学分析,组织学观察比较。结果术后45d和60d,X线片及骨密度检测显示实验组牵伸骨痂形成量及骨密度值明显高于对照组(P<0.05),75d两组比较差异无显著意义;组织学观察发现45d实验组成熟软骨和类骨组织形成量均较对照组多,实验组新生骨痂内毛细血管数量较多,60d实验组可见大量新生骨组织,有丰富的骨髓腔和原始骨髓,对照组以类骨组织为主,原始骨髓少,75d两组间组织学形态趋于一致。结论在兔胫骨牵伸骨形成过程中,ESW可加速骨痂的早期形成、矿化和改建。     

Temporal and spatial expression of bone morphogenetic protein-2, -4, and -7 during distraction osteogenesis in rabbits

The Ilizarov method of limb lengthening makes use of the fact that osteogenesis is induced at an osteotomy site when distraction is applied. It is unknown at present how the mechanical forces created by distraction are translated into biological signals. Because bone morphogenetic proteins (BMPs) are potent inducers of osteogenesis in many experimental systems, they are obvious candidates for playing a role in this process. In this study, we investigated the temporal and spatial expression of BMP-2, -4, and -7 proteins during distraction osteogenesis using immunohistochemistry. An osteotomy was performed on the right tibiae of white New Zealand rabbits. After a delay of 7 days, distraction was started at a rate of 0.25 mm/12 h for 3 weeks, followed by a 3 week consolidation phase. Each week after osteotomy one rabbit was killed for immunohistochemical studies. Staining for BMP-2, -4, and -7 was evident before distraction was applied and was mainly localized to mesenchymal cells and osteoblastic cells in the periosteal region. After distraction was started, the typical fibrous interzone developed between the osteotomy fragments, where both intramembranous and endochondral ossification were noted. In this area, cells resembling fibroblasts and chondrocytes, but not mature osteoblasts, showed intense staining for all three BMPs. This high level of expression was maintained during the entire distraction phase and then gradually disappeared during the consolidation phase. These results are compatible with the hypothesis that BMPs play an important role in the signaling pathways that link the mechanical forces created by distraction to biological responses.     

Temporal and spatial expression of bone morphogenetic protein-2, -4, and -7 during distraction osteogenesis in rabbits

The Ilizarov method of limb lengthening makes use of the fact that osteogenesis is induced at an osteotomy site when distraction is applied. It is unknown at present how the mechanical forces created by distraction are translated into biological signals. Because bone morphogenetic proteins (BMPs) are potent inducers of osteogenesis in many experimental systems, they are obvious candidates for playing a role in this process. In this study, we investigated the temporal and spatial expression of BMP-2, -4, and -7 proteins during distraction osteogenesis using immunohistochemistry. An osteotomy was performed on the right tibiae of white New Zealand rabbits. After a delay of 7 days, distraction was started at a rate of 0.25 mm/12 h for 3 weeks, followed by a 3 week consolidation phase. Each week after osteotomy one rabbit was killed for immunohistochemical studies. Staining for BMP-2, -4, and -7 was evident before distraction was applied and was mainly localized to mesenchymal cells and osteoblastic cells in the periosteal region. After distraction was started, the typical fibrous interzone developed between the osteotomy fragments, where both intramembranous and endochondral ossification were noted. In this area, cells resembling fibroblasts and chondrocytes, but not mature osteoblasts, showed intense staining for all three BMPs. This high level of expression was maintained during the entire distraction phase and then gradually disappeared during the consolidation phase. These results are compatible with the hypothesis that BMPs play an important role in the signaling pathways that link the mechanical forces created by distraction to biological responses.     

Novel approach to calvarial bone transport using a rabbit model

Calvarial defects sometimes require cranioplasty to protect the brain. Alloplastic materials, such as acrylic resin, hydroxyapatite ceramics, and titanium, involve various problems, such as vulnerability, infection, deformity resulting from growth, and high cost. We devised a new bone transport model in the rabbit based on the distraction osteogenesis theory of Ilizarov. Twelve Japan white rabbits with a mean body weight of 2.5 kg aged 12 weeks were used. Craniectomy (7 x 14 mm) was performed in 12 rabbits. Trapezoid bone osteotomy was performed anterior to the calvarial defect in 10 rabbits. The distraction device (Extension-plates) was fixed between the trapezoid bone island and the skull. Distraction was initiated 5 days postoperatively. The device was activated once every other day, with approximately 0.75 mm or 0.5 mm per activation. Bone distraction was continued until the rod could not be moved. The lengths of distraction were 4 mm in two cases, 5 mm in one case, 6 mm in one case, and 7 mm in two cases, with a mean of 5.5 +/- 0.56 mm. Both radiographic and histological findings showed osteogenesis by intramembranous ossification and trans-chondroid bone formation. Distraction osteogenesis has potential clinical applications in cranioplasty, especially in children because usage of autogenous bone is difficult if not impossible in most cases.     

带血运骨膜管移植和骨充填物修复桡骨长段缺损的研究

目的：探讨联合应用带血运骨膜管移植和骨充填物治疗兔桡骨长段缺损的效果。方法：实验分两部分，分别选用幼兔和成年兔各40只，根据填充物的不同分为4组，将兔双侧桡骨干中段切除3cm制成骨长段缺损模型，保留切骨段骨膜，重新重原缝合后作带血运骨膜管移植模型，左侧分别用自体骨，同种异体脱钙骨，磷酸三钙陶瓷和羟基磷灰石进行填充，右侧不行任何填作为对照。观察3个月。通过X线片，髓强度，骨密度和组织学检查等方法，了解骨缺损的修复效果。结果：幼兔术后6周，所有实验组双侧的骨缺损均得到修复，术后12周，磷酸三钙陶瓷和羟基磷灰石组桡骨抗弯曲强度较差与自体骨组、同种异体脱钙骨组和对照侧比较具有统计学意义（P＜0．05）；骨愈合为膜内成骨和软骨成骨，以膜内成骨为主，成年兔；各组实验侧骨缺损修复率分别为：自体骨组50％；同种异体脱钙骨组40％；磷酸三钙陶瓷和羟基磷灰石组为30％。对照侧骨缺损修复率为42．5％，结论：幼兔单行单血运骨管移植或结合应用骨充填物均可有效修复骨长段缺损，但置换较慢的骨充填物不利于再生骨强度的恢复，成年兔带血运骨膜移植联合应用骨填充物不能有效修复骨长段缺损。     

Effect of distraction frequency on bone formation during bone lengtheningA study in chickens

We compared the effects of two distraction frequencies on bone formation during tibial lengthening by evaluating radiographs, bone mineral density, and histological findings. In 15 mature White Leghorn chickens, both tibiae were distracted at a rate of 0.75 mm/day for 10 days. The distraction frequency was 2 steps (0.375 mm/12 hour) by hand on the right side and 120 steps (0.00625 mm/12 min) by autodistractor on the left. Serial radiographs showed faster bone formation on the 120-step side than on the 2-step side. Bone mineral density on the 120-step side was also higher than that on the 2-step side at all times. On the 2-step side, endochondral ossification was marked in the early stage of distraction; then intramembranous ossification became the main mechanism of bone formation. On the 120-step side, however, intramembranous bone formation predominated throughout the study. Our findings support the contention that, at least in skeletally mature chickens, an increase in the distraction frequency improves osteogenesis during bone lengthening.     

Osteogenic ability of free periosteal autografts in tibial fractures with severe soft tissue damage: an experimental study

OBJECTIVE: The present study was undertaken to assess whether free nonvascularized autologous periosteum transplants enhance bone healing in a rabbit fracture model designed to resemble a tibial fracture with severe soft tissue damage. DESIGN: Transplantation of free autologous periosteal grafts on the anteromedial site of the tibia (experimental group) was compared with nontransplantation on the contralateral tibia (control group). We produced a standardized transverse osteotomy of both tibial diaphyses in white male adult New Zealand rabbits. The endomedullary cavity was reamed and nailed, and then a one-centimeter segment of periosteum was excised from either side of the osteotomy. To prevent periosteal and extraosseous ingrowth at the osteotomy site, a silastic sheet was wrapped around two-thirds of the circumference of the tibia. In the first group, on the silastic-free bone window, we then spanned the osteotomy with a free, nonvascularized, longitudinally oriented autologous periosteum and sewed it to the adjacent periosteum both proximally and distally. In the second group, the periosteum was placed transversely, leaving a gap between it and the adjacent periosteum proximally and distally. Revascularization of the graft was determined with the colored microsphere technique. MAIN OUTCOME MEASUREMENTS: Histomorphometric analysis of the periosteal callus was done on a transparent grid superimposed on enlarged photographs of the histologic sections. RESULTS: Free, nonvascularized, longitudinally placed autologous periosteum in contact with intact periosteum produced significantly more periosteal callus than was seen in the control group, in which no periosteal graft was used. However, when transversely placed periosteal grafts were set in the silastic-free bone window and there was no contact with surrounding remnants of intact periosteum, no significant difference in callus production was noted when compared with the control. Revascularization of these grafts was seen within one week after transplantation. Bone healing occurred mainly through endochondral ossification. CONCLUSION: Our data suggest that orthotopically placed autologous nonvascularized periosteum retains its osteogenic potential in a poorly vascularized environment such as a tibial fracture with severe soft tissue damage. The effect is enhanced if the graft is in contact with intact periosteum. Histologically, callus formation after periosteal grafting resembles endochondral and intramembranous ossification.