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.     

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。     

骨髓基质干细胞与生物衍生骨复合修复山羊胫骨缺损的研究

目的　探讨骨髓基质干细胞 (marrow stromal stem cells,MSCs)与生物衍生骨复合修复山羊胫骨的长段骨 -骨膜缺损的可行性。　方法　将 12月龄山羊 35只双侧胫骨制备成中段 2 0 mm的骨 -骨膜缺损 ,其中 33只 ,将MSCs与生物衍生骨于体外复合培养后 ,将其植入右侧缺损处 ,常规钢板螺钉内固定作为实验组 ,以单纯生物衍生骨植入左侧作为对照组 ,另 2只为空白组不植入任何材料 ,在 2、4、6、8、12、16及 2 4周各时间点分别行大体标本、组织学观察 ,以及生物力学测试 ,比较 3组骨缺损修复的能力。　结果　 4周时实验组支架材料部分吸收 ,植入物表面有纤维骨痂形成 ,对照组支架材料少量吸收 ,植入物表面有少量骨样组织形成 ;8周时 ,大体标本、组织学观察 ,实验组中的支架材料已完全降解 ,骨缺损部分修复 ,对照组中植入物两端少量新骨形成 ,材料中为纤维骨样组织 ,但 8周时 ,实验组与对照组的生物力学强度差异无统计学意义 (P>0 .0 5 ) ;12周时 ,实验组骨缺损完全修复 ,对照组植入物两端有新骨包绕 ,与骨端连接紧密。 12～ 2 4周实验组弯曲应力大于对照组有统计学意义 (P<0 .0 5 ) ;2 4周时空白组骨缺损未修复。　结论　所构建的组织工程骨修复能力较强 ,成骨迅速 ,且量大 ,同期新生骨组织的生物力学强度优于单纯     

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。     

Effect of IR laser photobiomodulation on the repair of bone defects grafted with organic bovine bone

A major problem on modern dentistry is the recovery of bone defects of different etiologies. Biomaterials are used to improve the repair of these defects. Previous studies have shown positive effects of Laser Photobiomodulation (LPBM) on the repair of both soft and bone tissues. This study assessed histologically the effect of LPBM on the repair of surgical defects on the femur of rats filled with lyophilized bovine bone. The animals were divided into three groups: group I (control); group II (graft); group III (graft + LPBM). The animals on the irradiated groups received 16 J/cm(2) per session divided into four points around the defect being the first irradiation immediately after surgery and repeated at every 48 h during 2 weeks. Animal death occurred 15, 21, and 30 days after surgery. The specimens were routinely processed and stained with H/E and Sirius red and analyzed by light microscopy. There was histological evidence of improved collagen fiber deposition at early stages of the healing; increased amount of well-organized bone trabeculae at the end of the experimental period on irradiated animals. It is concluded that LPBM has positive biomodulative effect on the healing process bone defects.     

Histological examination of bone regeneration achieved by combining grafting with hydroxyapatite and thermoplastic bioresorbable plates

In this study, we present a novel guided bone regeneration (GBR) concept that consists of combining Boneject, a bone substitute containing atelocollagen and bovine hydroxyapatite particles, with thermoplastic, bioresorbable plates (DeltaSystem) known to resist mechanical loading. In rat calvariae, standardized bone defects were filled with Boneject and covered with a convex DeltaSystem plate. Tissue from rats at 1, 2, 4, 8, and 12 weeks postoperation were fixed with an aldehyde solution, and the new bone formed at the defects was histologically assessed. At 1 week, alkaline phosphatase (ALP)-negative cells deriving from the bottom region of the defect could be found up to half the height of the cavity. Boneject particle surfaces in the bottom region revealed an intense osteopontin immunopositivity whereas those in the upper region did not. Tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts accumulated on the surfaces of osteopontin-coated particles. A newly formed, woven-like bone featuring ALP-positive osteoblasts extended from the native bone. At the second week, the newly formed woven bone had surrounded the Boneject particles. Cement lines, which indicate active bone remodeling, could be observed in the new bone despite its immaturity. Four weeks after surgery, the new bone had reached the height of the DeltaSystem plate, and just beneath it a periostin-positive fibrous layer covered the mix of new bone and Boneject particles. By then, despite having acceptable histological features, electron probe microanalyzer (EPMA) and transmission electron microscope (TEM) analyses revealed that the new bone could not be regarded as compact bone. At 8 and 12 weeks, the new bone showed compact bone-like features according to TEM and EPMA assessments. Summarizing, the combination of a bone substitute such as Boneject and a rigid, bioresorbable plate appears to be osteoconductive and to promote bone remodeling, leading to the genesis of a tissue similar to the one that is regarded as the “gold standard” for bone regeneration: the compact bone.     

Studies on Mechanical Strength of Bone: II. Torsional Strength of Cortical Bone after Rigid Plate Fixation with and without Compression

Biomechanical properties of intact rabbit tibio-fibulae were investigated with torsional loading 1 day to 36 weeks alter fixation using 4-hole stainless steel ASIF/DCP plates with and without compression.

During the first 12 weeks energy absorption and torque moment increased slightly as a result of subperiosteal new bone formation following application of the plates. There was a concomitant increase in the yielding properties of the bone, reflecting progressive porotic transformation. Thereafter, up to 36 weeks postoperatively, the values for energy absorption, torque moment and angular deformation gradually declined in both groups of bones. The differences between normal control bones and plated bones at 36 weeks were 70.1, 53.0 and 26.3 per cent, respectively. The decay of torsional strength was the same whether or not compression was used in the plate fixation.

The results suggest that even in normal bone rigid plates induce a considerable loss of strength due to the cancellous transformation they are known to cause in cortical bone.     

微创植骨术与开放植骨术治疗骨缺损的对比研究

目的观察微创植骨术治疗骨缺损的疗效。方法建立兔双侧桡骨干骨缺损模型。将每只动物双侧前肢随机分入开放植骨术组(A组)和微创植骨术组(B组)。B组用自行研制的微创植骨器进行微创植骨。术后不同时间对骨缺损部位进行双能X线骨密度检查、光镜观察和电镜观察。结果术后不同时间两组骨缺损部位的骨密度随时间延长逐渐增高,但同一时间B组的骨密度均高于A组,两组差异有显著性(P<0.01);光镜观察B组骨小梁形成速度快于A组,骨小梁向板层骨塑形时间亦早于A组;电镜观察B组成纤维细胞和成骨细胞出现时间、两种细胞内细胞器活跃程度、细胞周围胶原纤维及钙盐的沉积数量均优于A组,新生骨塑形速度亦快于A组。结论用微创植骨器治疗骨缺损,在减小手术创伤的同时可加快骨缺损的修复速度,提高骨缺损的修复质量。     

Loading induces site-specific increases in mineral content assessed by microcomputed tomography of the mouse tibia

Adaptation to mechanical loading has been studied extensively in cortical, but not cancellous bone. However, corticocancellous sites are more relevant to osteoporosis and related fracture risk of the hip and spine. We tested the hypotheses that adaptation in a long bone would be greater at cancellous than cortical sites and would depend on the term of daily in vivo cyclic axial loading. We applied compressive loads to the adolescent, 10-week old, male C57BL/6 mouse tibia to examine the skeletal response immediately prior to attainment of peak bone mass. Adaptation was quantified at the completion of either 2-week (n = 8) or 6-week (n = 12) loading terms by directly comparing volumetric bone mineral content between loaded and contralateral limbs by microcomputed tomography. The increase in mineral content was site specific with a greater response found in the corticocancellous proximal metaphysis (14%) than the cortical mid-shaft (2%) after 6 weeks of loading. Furthermore, bone volume fraction and average trabecular thickness of cancellous bone in the proximal tibia increased after 6 weeks by 15% and 12% respectively. Diaphyseal response was only evident proximal to the mid-shaft as indicated by an 8% increase in maximum principal moment of inertia. Both loading terms produced similar results for mineral content, volume fraction, and moments of inertia. Our finding that non-invasive loading increases the bone volume and fraction at a corticocancellous site by as much as 15% motivates exploring the use of mechanical loading to attain greater peak bone mass and inhibit osteoporosis.     

Bending and torsion stability of healed metatarsus osteotomy after plate osteosynthesis

72 transversal osteotomies on metatarsus of sheep were stabilized under contact or gap conditions with three different thicknesses of bone plates. After 16 weeks we measured bending or torsion break loading, moment of inertia of bone by transmission methode and calculated moments of bending and torsion strength. Results: ultimate bending strength on osteotomied bone 100.4 +/- 14.4 N/mm2 under contact, and 77.4 +/- 11.4 N/mm2 under gap condition, torsion bending strength 26.1 +/- 4.9 N/mm2 under contact, and under gap condition 21.5 +/- 4.3 N/mm2. The best results were given by the 2.8 mm plate with the same moment of inertia like the small ASIF plate.     

组织工程引导骨再生膜修复节段性骨缺损

目的　将组织工程技术和引导性骨再生技术相结合修复长骨节段性缺损。方法　兔 2 7只 ,动物模型均为桡骨 1 2cm节段性骨 骨膜缺损 ,分成 3组 ,A组 :利用体外构建的细胞 材料复合物膜修复 ;B组 :利用单纯的膜材料进行修复 ;C组 :断端不作任何处置作空白对照。分别观察 3、 6、 12周后进行X线观察和组织学观察。结果　A组的骨愈合优于B组 ,在 12周时已经完成骨缺损的修复 ,B组在术后 12周仍处于塑形改建之中 ;C组 12周形成典型的骨不连。结论　将组织工程的技术与引导性骨再生技术相结合 ,可以比单纯的引导性骨再生更好地修复长骨节段性缺损。     

Pause Insertions During Cyclic In Vivo Loading Affect Bone Healing

Fracture repair is influenced by the mechanical environment, particularly when cyclic loads are applied across the fracture site. However, the specific mechanical loading parameters that accelerate fracture healing are unknown. Intact bone adaptation studies show enhanced bone formation with pauses inserted between loading cycles. We hypothesized pause-inserted noninvasive external loading to mouse tibial fractures would lead to accelerated healing. Eighty mice underwent tibial osteotomies with intramedullary stabilization and were divided into four loading protocol groups: (1) repetitive loading (100 cycles, 1 Hz); (2) pause/time-equivalent (10 cycles, 0.1 Hz); (3) pause/cycle-equivalent (100 cycles, 0.1 Hz); and (4) no load control. Loading was applied daily for 2 weeks. Healing was assessed using histology, biomechanical bending tests, and microcomputed tomography. The pause-inserted, cycle-equivalent group had a greater percentage of osteoid present in the callus cross-sectional area compared with no-load controls, indicating more advanced early healing. The pause-inserted, cycle-equivalent group had a failure moment and stiffness that were 37% and 31% higher than the controls, respectively. All three loaded groups had smaller overall mineralized callus volumes than the control group, also indicating more advanced healing. At an early stage of fracture healing, pause-inserted loading led to more histologically advanced healing. One or more of the authors have received funding from the Orthopaedic Trauma Association (MJG), the Orthopaedic Research and Education Foundation (MJG), and NIH Musculoskeletal Core Center P30AR046121 (TMW, MCHvdM). Each author certifies that his or her institution has approved the animal protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research.     

异种脱蛋白骨复合物修复大段骨缺损的血管化观察

[目的]探讨异种脱蛋白骨(heterogeneous deprotein bone,HDPB)复合物修复胫骨大段骨缺损过程中的血管化实验研究,为异种脱蛋白骨的临床应用提供实验依据。[方法]山羊24只,在右侧胫骨中下段截除胫骨总长度20%形成节段性骨缺损,实验组18只,植入异种DPB 自体MSCs rhBMP2,用半环槽式外固定器固定。于术后每隔4周对3只进行股动脉墨汁灌注后处死,取新骨组织制成厚切片观察血管化情况,以另6只植入自体骨为对照。[结果]术后4~24周,实验组与对照组血管表现数目逐渐增多,排列渐趋规则,血管大小、分布区域趋向均匀。测量血管数目和面积,结果显示4~24周2组血管数目和面积统计学分析差异无显著性意义(P>0.05)。[结论]异种脱蛋白骨复合物修复大动物大块骨缺损过程中血管化程度与自体骨相当,可以作为组织工程支架材料,并对其免疫原性和成骨能力等性能进行进一步研究。     

Can rhBMP-2 Containing Collagen Sponges Enhance Bone Repair in Ovariectomized Rats?: A Preliminary Study

With an aging population the frequency of postmenopausal fractures is increasing. Methods to enhance the repair of osteoporotic bone repair therefore become more important to reduce the society burden of care. We asked if absorbable collagen sponges containing recombinant human bone morphogenetic protein-2 (rhBMP-2) have the potential to enhance bone repair. We randomly assigned 40 rats into the ovariectomy and sham operation groups. A segmental defect was created in the right tibia 12 weeks after ovariectomy. rhBMP-2-containing absorbable collagen sponges were implanted into the defect in half of the animals in each group. We analyzed radiographs and histological sections and performed three-point bending tests to assess repair. Radiological scores in the rhBMP-2 applied rats were higher than those in controls at the end of 8 weeks after tibial osteotomy. The specimens failed under higher loads in the rhBMP-2-applied groups and histology revealed a higher fracture healing score, including callus formation, bone union, marrow changes, and cortex remodeling. We observed no adverse tissue responses such as fibrous connective tissue formation and inflammatory cellular infiltration. rhBMP-2 in absorbable collagen sponges enhanced bone repair in segmental tibial defects of ovariectomized rats. The sponges with rhBMP-2 appeared to enhance bone repair.     

bFGF/BMP/AACB复合物修复犬股骨头缺损坏死模型的实验研究

目的制备bFGF/BMP/AACB复合物,通过动物实验研究其对股骨头缺损坏死模型的修复作用及相关问题,探讨临床应用的可能性。方法制备异体脱抗原松质骨(AACB),并将其与碱性成纤维细胞生长因子(bFGF)及骨形态发生蛋白(BMP)复合制成bFGF/BMP/AACB复合物,植入通过液氮冷冻建立的犬股骨头缺损坏死模型,术后不同时间处死动物。通过大体解剖、X线片、组织学染色、图像分析、血管免疫组化染色、X线能谱分析、生物力学测定等手段观察缺损坏死模型的修复情况。结果术后各组动物均无毒性反应和炎症反应。A组(空白缺损组)术后12周缺损仍未愈合;B组(AACB组)虽然优于A组,但成骨作用不及C组(BMP/AACB组);而D组(bFGF/BMP/AACB组)成骨和成血管作用优于A、B、C组。早期(3、6周)甚至优于E组(自体骨组),后期(12周)的骨修复及骨改建效果与E组相当。结论bFGF/BMP/AACB复合物具有明显促进犬股骨头缺损坏死模型再血管化及新骨形成的作用,可望成为新型的股骨头缺血性坏死(ANFH)修复材料。     

Fractures of the Humerus from Muscular Violence

Biomechanical properties of intact rabbit tibio-fibulae were investigated with torsional loading 1 day to 36 weeks alter fixation using 4-hole stainless steel ASIF/DCP plates with and without compression.

During the first 12 weeks energy absorption and torque moment increased slightly as a result of subperiosteal new bone formation following application of the plates. There was a concomitant increase in the yielding properties of the bone, reflecting progressive porotic transformation. Thereafter, up to 36 weeks postoperatively, the values for energy absorption, torque moment and angular deformation gradually declined in both groups of bones. The differences between normal control bones and plated bones at 36 weeks were 70.1, 53.0 and 26.3 per cent, respectively. The decay of torsional strength was the same whether or not compression was used in the plate fixation.

The results suggest that even in normal bone rigid plates induce a considerable loss of strength due to the cancellous transformation they are known to cause in cortical bone.     

Evaluation of the effects of systemic treatment with a sclerostin neutralizing antibody on bone repair in a rat femoral defect model

Systemic administration of a sclerostin neutralizing antibody (Scl‐Ab) has been shown to enhance fracture callus density and strength in several animal models. In order to further evaluate the potential of Scl‐Ab to improve healing in a bone defect model, we evaluated Scl‐Ab in a 3 mm femoral defect in young male outbred rats. Scl‐Ab was given either continuously for 6 or 12 weeks after surgery or with 2 weeks of delay for 10 weeks. Bone formation was assessed by radiographs, µ‐CT, and histology. Complete bony union was achieved in only a few defects after 12 weeks of healing (Scl‐Ab treated 5/30, vehicle treated 1/15). µ‐CT evaluation demonstrated a significant increase in the BV/TV in the defect in the delayed treatment group (65%, p < 0.05), but a non‐significant increase in the continuous group (35%, p = 0.11) compared to control. However, both regimens induced an anabolic response in the bone proximal and distal to the defect and in the un‐operated femurs. We demonstrate that treatment with Scl‐Ab can enhance bone repair in a bone defect and in the surrounding host bone, but lacks the osteoinductive activity to heal it. This agent seems to be most effective in bone repair scenarios where there is cortical integrity. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:197–203, 2014.     

钛板固定的BMSC/松质骨基质复合物修复兔股骨缺损

目的: 观察钛板加强固定的骨髓基质细胞 (BMSC) /松质骨基质复合物修复股骨缺损的能力。方法: 体外培养兔BMSC经扩增, 诱导分化后复合同种异体松质骨基质, 植入自体股骨缺损区, 修复骨缺损, 钛板固定和加强, 植入 6、12周后经大体观察, 组织学检查, 骨磨片观察骨形成情况。结果: BMSC/松质骨基质复合物有很强的成骨作用, 实验组X线观察有骨形成, 组织学染色证实有新骨形成, 骨磨片显示钛板和新骨获得良好的结合。结论: 钛板加强的BMSC/松质骨基质可诱导修复兔股骨缺损, 为组织工程方法修复骨缺损提供了新的思路。     

可塑形组织工程骨修复兔颅骨缺损的组织学及力学研究

目的探讨用藻酸钙凝胶、成骨细胞和骨粉复合构建可塑形组织工程骨修复兔颅骨缺损后,体内成骨的组织学及生物力学特征。方法28只日本大耳白兔,随机分为A组(16只)、B组(8只)和C组(4只)。制备兔颅骨左右两侧直径1cm的骨膜-颅骨全层缺损,左侧用藻酸钙凝胶-成骨细胞-骨粉填补修复为A1组(n=16);右侧用藻酸钙凝胶-骨粉填补修复为A2组(n=16);B组骨缺损不作处理,为空白对照组(n=16);C组为正常组。术后6周和12周时,行大体观察及组织学观察;12周时行生物力学测试。结果术后6、12周时,A1组:颅骨缺损基本被硬组织所修复,镜下见材料已大部分被骨组织替代,成骨面积为40.92%±19.36%;A2组:材料部分被骨组织替代,成骨面积为18.51%±6.01%;B组:颅骨缺损边缘可见硬组织形成,镜下见修复组织以致密纤维组织为主,成骨面积为12.72%±9.46%。术后12周,生物力学测试修复组织能耐受的最大压力载荷,A1组37.33±2.95N;A2组30.59±4.65N;B组29.5±2.05N;C组41.55±2.52N;A1组明显大于A2组和B组(P<0.05)。最大载荷时应变位移,A1组1.05±0.20mm;A2组1.35±0.44mm;B组1.57±0.31mm;C组0.95±0.17mm;A1组小于B组(P<0.05)。载荷/应变比值,A1组35.82±6.48N/mm;A2组24.95±12.40N/mm;B组19.90±5.47N/mm;C组47.57±11.22N/mm;A1组大于B组(P<     

The influence of different degrees of stiffness of fixation plates on experimental bone healing

In order to throw some light on the controversial issue of the optimal stiffness in fracture fixation, the effects on bone healing of rabbit tibial osteotomies fixed by plates with four different degrees of stiffness were studied. The least stiff plate was made of glass fiber-reinforced epoxy; the other three were made of stainless steel. The median bending stiffness in vitro of tibial osteotomies fixed with the various plates were 13%, 17%, 61%, and 74%, related to the stiffness of intact tibiae. Transverse midshaft unilateral tibial osteotomies were fixed by the various plates, and the animals were killed after 6 weeks. The amount of periosteal callus was inversely related to the stiffness of the plates. A marked trend toward decreased strength and stiffness occurred in tibiae where the most rigid plate was used, compared with the values of those with the less rigid plates. This indicates that the stress-protecting effect of very stiff plates begins early in the healing period and is pronounced even at 6 weeks and that a steel plate of lower stiffness is more appropriate for bone healing. However, too flexible plates involve increased risk of redislocation and mechanical failure.