应用体外分离培养破骨细胞的技术评价人工骨

本文介绍如何应用分离培养破骨细胞的技术评价人工骨。家兔48只,随机分成A、B、C、D四组,每组12只,人工造成家兔同侧桡骨10mm缺损。分别植入不同材料的骨移植物,A组为珊瑚羟基磷灰石,B组为人工合成羟基磷灰石,C组为人工多聚体,D组为自体骨。移植术后6、8、12、16周,分期处死动物,取出植入动物体内骨移植物并制成骨磨片,与体外分离的破骨细胞共同培育1周,扫描电镜发现,破骨细胞能够在植入动物体内的人工骨片上产生骨吸收。实验比较表明各组植骨材料的成骨能力依次为:自体骨>珊瑚羟基磷灰石>人工合成羟基磷灰石>人工多聚体(P<0.01或P<0.05),珊瑚羟基磷灰石的成骨能力优于其它两种人工骨,但逊于自体骨。     

HA、RBM、BMP及FS复合物修复骨缺损的实验研究

目的探讨羟基磷灰石HA、自体红骨髓RBM、骨形态发生蛋白(BMP)及纤维蛋白(FS)复合物修复骨缺损的能力及其作为人工骨移植替代材料的可行性。方法在新西兰大白兔双侧桡骨制备骨缺损模型,将HA-RBM-BMP-FS复合物植入骨缺损动物模型处,以自体骨移植及空白组(不植入任何物质)作为对照,在2、4、8、12周四个时间点分别进行大体标本观查、组织病理学、X线片观察及生物力学测试,比较三者修复骨缺损的能力。结果大体标本观查、组织病理学、X线片显示,在12周,HA-RBM-BMP-FS复合物与自体骨移植组骨缺损均已完全修复,HA无明显吸收,而空白对照组骨缺损未修复;生物力学测试显示自体骨移植组与HA-RBM-BMP-FS复合物组差异无显著性意义。结论HA-RBM-BMP-FS复合物具有较强的成骨能力,可修复骨缺损,并能作为自体骨移植的一种替代物。     

纳米陶瓷人工骨修复骨缺损的实验研究

目的通过动物实验探讨纳米陶瓷人工骨的骨缺损修复作用及相关问题,为其应用于骨缺损的修复提供依据。方法青紫兰兔45只在单侧桡骨制备骨缺损动物模型,随机分成3组(每组15只),然后用纳米陶瓷人工骨材料植入骨缺损处进行修复作为实验组,以植入陶瓷人工骨为对照组,空白组不植入任何材料;术后4、8、12周分别行大体标本观察、组织学、X线检查、扫描电镜(SEM)测试,比较三组间骨缺损区的成骨情况。结果纳米陶瓷人工骨成骨作用明显优于陶瓷人工骨组和空白对照组,差异有显著性意义(P<0．05)。结论纳米陶瓷人工骨具有良好的成骨能力、生物相容性和一定的降解率,是一种替代自体骨修复骨缺损较理想的材料。     

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。     

胎骨移植成骨特性实验观察

胎骨的化学组成和组织结构与成年骨均有不同。成年骨移植的成骨过程可能与胎骨不同,胎骨移植可能具有特殊的成骨过程。本实验的目的是对上述推论加以证实,明确胎骨移植是否优于成年骨。1 材料和方法1.1 实验动物及分组 成年雄性大耳白家兔29只,体重2kg～2.5kg,随机分为A、B、C3组,每组9只,各组分别移植胎骨,同种异体骨和自体骨。术后3周、6周、9周进行X线及组织学观察。另设2只空白对照。     

牛脱蛋白松质骨、胶原、BMP、RBM复合物修复骨缺损的实验研究

目的探讨牛脱蛋白松质骨、胶原、骨形态发生蛋白(BMP)、自体红骨髓(RBM)复合物修复骨缺损的能力及其作为自体骨移植替代材料的合理性、可行性.方法在42只家兔双侧桡骨中段制备骨缺损模型,分为4组牛脱蛋白松质骨、胶原、BMP、RBM复合物植入组(A1组20侧)、单纯牛脱蛋白松质骨植入组(A2组20侧)、自体骨植入组(B1组20侧)、空白对照(B2组20侧).在2、4、8、12周分别进行大体标本观察、X线检查、病理组织学检查及生物力学测试.结果 12周时,A1组、B1组骨缺损均已完全修复,而A2组、B2组骨缺损未修复;生物力学测试术后4周A1组的最大扭矩和抗扭刚度均高于B1组,而术后8周后则无显著性差异.结论牛脱蛋白松质骨、胶原、BMP、RBM复合物具有较强的成骨能力,可修复骨缺损,并能作为自体骨移植的一种替代材料.     

自体骨泥混以骨膜碎片治疗骨缺损的实验及临床应用研究

[目的]观察自体骨泥混以骨膜碎片修复骨缺损的效果,探索治疗骨缺损的新方法。[方法]新西兰白兔36只,分3组,每组12只,所有动物均建立双侧桡骨中段1.5×0.3cm的骨缺损。左侧为实验侧,用自体骨泥混以骨膜碎片修复,右侧为对照侧,第1组对照侧为空白对照;第2组对照侧单用自体骨膜修复;第3组对照侧单用自体骨泥修复。于术后2、4、6、8、10、12周分别摄X线片,每时点每组处死2只动物,骨缺损段分析天平称重,双侧对比,光镜和电镜下观察组织学情况。临床应用34例,治疗骨肿瘤18例,陈旧性骨折骨不连16例。[结果]术后3组的实验侧骨量均明显多于对照侧,愈合时间较对照侧明显缩短;光镜和电镜下可见实验侧成骨的质量优于对照侧。34例临床应用全部获得随访,随访时间为9~38个月,平均17个月,18例骨肿瘤随访期内所有病例无复发,16例陈旧性骨折骨不连已全部愈合。[结论]自体骨泥混以骨膜碎片后成骨愈合能力明显增强,为临床提供了一种新的植骨方法。     

异种牙本质修复兔颅骨缺损的实验研究

目的:观察异种牙本质修复兔颅骨骨缺损的疗效,探索其作为骨移植替代材料的有效性。方法:将因正畸原因拔除的人健康前磨牙,制成直径2~3mm的牙本质块。在1%氯己定中浸泡5min。使用12只雄性健康新西兰大白兔,在颅骨各建立4个临界骨缺损,将自体骨、人牙本质随机填入骨缺损区,术后4、8、12周随机处死4只兔子,取出颅骨,通过大体观察、Micro-CT及组织学观察颅骨缺损修复情况,使用Micro-CT分析每个时间点新骨形成面积占骨缺损总面积百分比。结果:所有实验动物伤口愈合良好,未见明显炎症反应。经影像学评估,自体骨比异种牙本质成骨量相似,且差异无统计学意义(P>0.05)。组织学染色示:围绕在移植材料周围,可见新骨形成。结论:异种牙本质能促进和加速骨缺损的修复,有望为促进骨缺损的修复提供一种新思路。     

自体骨软骨移植与含富集骨髓干细胞松质骨移植修复兔关节软骨缺损

目的:评价自体骨软骨移植与含富集骨髓干细胞松质骨镶嵌移植两种方法修复全层关节软骨缺损的生物学特征和效果。方法:采用新西兰大白兔制作左右后肢全层软骨缺损模型,分别进行自体骨软骨镶嵌移植、含富集骨髓干细胞松质骨镶嵌移植修复,对照组不作任何修复,每组12只。术后第4、8、12周处死动物取材,分别进行膝关节活动度测定、大体观察、光镜观察与电镜观察。结果:移植实验组在第12周时均能以类透明软骨组织修复缺损,对照组为纤维肉芽组织。形态学检查表明,两种方法均能以类透明软骨组织覆盖缺损,骨软骨移植组无明显免疫排斥现象,随着时间延长,修复高度逐渐增加。骨软骨移植组同含富集骨髓干细胞松质骨镶嵌移植组效果无显著差别。结论:骨软骨移植、含富集骨髓干细胞松质骨镶嵌移植两种方法均能以类透明软骨组织修复全层关节软骨缺损,含富集骨髓干细胞松质骨镶嵌移植更适用于较大面积软骨缺损的修复。     

骨形态发生蛋白-2基因活化纳米骨浆修复兔桡骨缺损的实验研究

目的观察骨形态发生蛋白-2（BMP-2）基因活化纳米骨浆在损伤部位的局部成骨基因表达和骨缺损重建修复效果。方法新西兰白兔54只，其中48只实验动物随机分成三组（每组16只32侧），制成双侧桡骨中段15mm骨缺损模型。A组：注入hBMP-2＋纳米骨浆；B组：注入空白质粒＋纳米骨浆；C组：注入纳米骨浆。另6只动物制作左桡骨中段骨缺损，不植入材料，作为空白对照。术后4、8和12周取材行影像学检查、组织学观察、分子生物学检测和生物力学检测。结果术后12周A、B和C组骨缺损均修复，A组骨缺损处有明显BMP-2的mRNA和蛋白质表达，在ALP水平、成骨速度、新生骨量及新生骨力学强度等方面均明显优于B、C两组（P〈0．05）。空白对照组骨缺损无愈合。结论纳米骨浆复合BMP-2质粒后，具有一定骨诱导作用，植入体内后成骨速度、质量及力学强度较单纯的纳米骨浆明显增强，能够有效修复骨缺损。     

Vascularized bone graft in carpal bone reconstruction

We report our experience of vascularized bone graft harvested from the volar aspect of the distal radius for carpal bone reconstruction. Thirty cadaveric dissections showed in all cases the volar carpal artery which born from the radial artery. Between 1994 to 2001, we treated 87 scaphoid non-unions with an average follow-up of 41 months (range 6 to 65 months). Union was obtained in 80 patients (92%) with an average delay of 8.6 weeks (range 6 to 24). Between 1994 to 2000 we treated 22 patients with a Kienbock's disease. A radius shortening was always added to the revascularization of lunate by this vascularized bone graft. Preoperative and postoperative MRI was systematically done. The average follow-up was 55 months (range 24 to 92 months). MRI showed healing with good revascularization in 16 cases (74%). Lesions of lunate were stabilized in five cases and we had one failure with secondary palliative procedure. This simple but meticulous technique needs only one approach and allows a sufficient revascularisation.     

Trabecular bone remodeling and bone balance in hyperthyroidism

In vivo tetracycline double-labeled iliac crest bone biopsies from 15 hyperthyroid patients were used for the reconstruction of curves describing the variation of resorption depth and formation thickness with time. The curves emerging were compared to curves reconstructed from 13 age- and sex-matched normal individuals (mean age 44 years). The median function period for resorptive cells in hyperthyroid patients (16 days) was about one-third the resorptive period in normals (51 days). No significant difference between the osteoclast-, mononuclear-, or preosteoblast-like cell resorption depths could be demonstrated between the two groups. Consequently, the median resorption rate in hyperthyroid patients (3.8 μm/day) was more than 3 times higher than the value in the control group (1.1 μm/day). Median Sigma_f, was shorter in the hyperthyroid group (109 days) than in the control group (151 days, P < 0.05), as was the median initial mineralization lag time (5 and 16 days, respectively, P < 0.01). No significant difference between the measured mean completed wall thickness (mcwT) values in the hyperthyroid groups and the control group could be demonstrated (58.1 and 60.5 μm respectively). Median initial mineralization rate in the hyperthyroid group (1.2 μm³/μm² per day) was not significantly higher than the value calculated in the control group (0.9 μm³/ μm² per day), but median initial matrix appositional rate in hyperthyroids (4.8 μm³/μm² per day) was 3 times higher than the value calculated for normals (1.6 μm³/μm² per day) (P < 0.01). Direct measurements of mean completed wall thickness in the hyperthyroid group gave results (58.1 μm) that were not in accordance with the mean completed wall thickness calculated from the growth curve (52.1 μm, P < 0.02). In normals no such discrepancy could be demonstrated. Using the mcwT value estimated from the growth curve, the bone formation period was calculated to 90 days for hyperthyroid patients. This maximal estimate for mcwT was also significantly lower than the mean resorption depth measured in the hyperthyroid group (61.7 μm, P < 0.05), which means that a net negative balance per remodeling cycle existed in the hyperthyroid group. Bone balance was preserved in the control group.     

Preservation of bone morphogenetic protein in heat-treated bone.

In operations of bone tumors, reimplantation of resected bone after boiling or autoclaving is a simple means of obtaining both tumor necrosis and skeletal reconstruction. However, such reimplants lose their osteogenesity. We investigated whether bone inductive ability could be maintained in heat-treated bone. Bone morphogenetic protein (BMP) extracted from rabbit bone after heating for various periods at different temperatures was implanted into the muscles of mice to evaluate osteogenetic activity. The maximum new bone formation was observed in specimens treated at 70 degrees C for 10 minutes, followed by those treated at 70 degrees C for 15 minutes. We then measured the temperature in the center of a cortical bone heated in 0.15 N NaCl solution at 50 degrees, 60 degrees, 70 degrees, 80 degrees, and 90 degrees C. Cortical bone center temperature reached that of the surrounding solution within 2.5 minutes. These results indicated that heating at 70 degrees for 10 to 15 minutes was suitable for heat treated-bone to maintain bone inductive ability.     

Quantitative bone scan and bone metastases in prostatic cancer

Bone scan is an essential method of investigation for the detection of metastases; it is also used to follow the evolution of the disease and the response to treatment in prostatic cancer. The authors tried a bone scan quantification method to better evaluate the efficiency of hormonal treatment. 28 patients were followed up by this method. Taken as a whole, quantitative scans show results very similar to those of standard scans. However, there are some differences between the two methods of interpretation. The quantitative method seems to be more effective.     

Revascularization and new bone formation in heat-treated bone grafts

Human immunodeficiency virus (HIV) infection is one of the possible serious complications associated with bone allografts. In order to prevent infection, grafted bone is sterilized by various treatments. Heat treatment has attracted attention as a simple and practical method. We carried out a histological study of the influence of heat treatment on autogenic bone grafts. To eliminate the problem of antigenicity of grafted bone, we used autografts, not allografts. Three types of heat-treated autografts were employed: heat-treated at 60° C for 30 min, at 80° C for 10 min, and at 100° C for 5 min; as a control, fresh autografts were replaced in the rabbits’ ilium. One, 2, 4 and 8 weeks after grafting, we performed microangiography and prepared two types of samples: transparent and haematoxylin-eosin (H & E) stained. Then, using an image analyzer, we quantitatively measured revascularization and new bone formation in the grafted bone. The grafts heat-treated at 60° C showed early and good revascularization and new bone formation, from 1 to 8 weeks. The grafts heat-treated at 80° C showed relatively good revascularization and new bone formation. However, the grafts heat-treated at 100° C showed unsatisfactory revascularization and bone formation, less than 40% of control 8 weeks after grafting. Therefore, heat treatment at 60–80° C does not seriously affect revascularization and new bone formation. Received: 3 June 1997     

Mechanical consequences of bone loss in cancellous bone.

The skeleton is continuously being renewed in the bone remodeling process. This prevents accumulation of damage and adapts the architecture to external loads. A side effect is a gradual decrease of bone mass, strength, and stiffness with age. We investigated the effects of bone loss on the load distribution and mechanical properties of cancellous bone using three-dimensional (3D) computer models. Several bone loss scenarios were simulated. Bone matrix was removed at locations of high strain, of low strain, and random throughout the architecture. Furthermore, resorption cavities and thinning of trabeculae were simulated. Removal of 7% of the bone mass at highly strained locations had deleterious effects on the mechanical properties, while up to 50% of the bone volume could be removed at locations of low strain. Thus, if remodeling would be initiated only at highly strained locations, where repair is likely needed, cancellous bone would be continuously at risk of fracture. Thinning of trabeculae resulted in relatively small decreases in stiffness; the same bone loss caused by resorption cavities caused large decreases in stiffness and high strain peaks at the bottom of the cavities. This explains that a reduction in the number and size of resorption cavities in antiresorptive drug treatment can result in large reductions in fracture risk, with small increases in bone mass. Strains in trabeculae surrounding a cavity increased by up to 1,000 microstrains, which could lead to bone apposition. These results give insight in the mechanical effects of bone remodeling and resorption at trabecular level.     

Increase in bone volume fraction precedes architectural adaptation in growing bone

In mature trabecular bone, both density and trabecular orientation are adapted to external mechanical loads. Few quantitative data are available on the development of architecture and mechanical adaptation in juvenile trabecular bone. We studied the hypothesis that a time lag occurs between the adaptation of trabecular density and the adaptation of trabecular architecture during development. To investigate this hypothesis we used ten female pigs at 6, 23, 56, 104, and 230 weeks of age. Three-dimensional morphological and mechanical parameters of trabecular bone samples from the vertebra and proximal tibia were studied using microcomputed tomography and micro-finite element analysis. Both bone volume fraction and stiffness increased rapidly in the initial growth phase (from 6 weeks on), whereas the morphological anisotropy started increasing only after 23 weeks of age. In addition, the anisotropy reached its highest value much later in the development than did bone volume fraction. Hence, the alignment of trabeculae was still progressing at the time of peak bone mass. Therefore, our hypothesis was supported by the time lag between the increase in trabecular density and the adaptation of the trabecular architecture. The rapid increase of bone volume fraction in the initial growth phase can be explained by the enormous weight increase of the pigs. The trabeculae aligned at later stages when the increase in weight, and thus the loading, was slowed considerably compared with the early growth stage. Hence, the trabecular architecture was more efficient in later years. We conclude that density is adapted to external load from the early phase of growth, whereas the trabecular architecture is adapted later in the development.