Evaluation of a Fiber Reinforced Drillable Bone Cement for Screw Augmentation in a Sheep Model—Mechanical Testing

We evaluated the mechanical properties of a novel fiber reinforced calcium phosphate at time zero and after 12 weeks in vivo using a sheep long bone osteotomy model. Time zero data were obtained and compared by pullout testing of 4.5 mm bone screws from bone proper and overdrilled defects of 4.5 and 8 mm diameter. Defects were augmented with: polymethylmethacrylate (PMMA), calcium phosphate, and fiber reinforced calcium phosphate using cadaveric sheep tibiae. Twelve‐week data were obtained from explanted tibiae of sheep that underwent unilateral tibial osteotomy surgery repaired with a locking compression plate. The most distal hole was overdrilled to 4.5 or 8 mm diameter, filled with fiber reinforced cement, drilled, tapped and a 4.5 mm screw was placed. Screw holding strength at t= 0 was significantly higher for reinforced when compared to nonreinforced cement, but not different from bone or PMMA in 4.5 mm defects. There was no difference in pullout strength for the 8 mm defect data. After 12 weeks fiber reinforced pullout strength increased by 45% and 8.9% for 4.5 and 8 mm defects, respectively, when compared to t= 0 testing. Fiber reinforced calcium phosphate bone cement can be drilled and tapped to support orthopedic hardware for trauma applications. Clin Trans Sci 2010; Volume 3: 112–115     

骨形态发生蛋白复合材料修复兔皮质骨缺损

目的通过磷酸钙骨水泥(CPC)复合同种异体脱钙骨基质颗粒(DBM)及骨形态发生蛋白(bBMP)修复皮质骨缺损,探讨其对骨缺损的修复情况。方法在兔前肢桡骨制作长1cm的骨缺损,填充CPC与复合bBMP异体同种的DBM的复合物,应用大体标本观察、X线摄片、组织学观测、印度墨汁灌注等方法观察其对骨缺损的修复情况,对侧以单纯的CPC做对照。结果第2周开始复合材料组有血管长入,第4周X线片上显示可见、骨痂形成,12周后,复合材料与两端的骨质愈合良好,局部板层骨致密,哈夫氏系统排列整齐。结论磷酸钙骨水泥复合bBMP及同种异体脱钙骨颗粒修复、皮质骨缺损有较好的效果。     

磷酸钙人工骨联合雷洛昔芬修复兔下颌骨缺损

背景：雷洛昔芬是第3代选择性雌激素受体调节剂,可减少骨量的丢失,增加骨组织中的矿物质含量,降低骨折风险。目的：观察雷洛昔芬结合自固化磷酸钙人工骨修复兔下颌骨缺损的效果。方法：在36只新西兰大白兔左侧下颌骨制作8 mm×4 mm×3 mm的缺损模型,随机分组,实验组12只植入自固化磷酸钙人工骨,并给予雷洛昔芬7.5 mg/（kg·d）;药物组12只给予雷洛昔芬7.5 mg/（kg·d）;人工骨组12只植入自固化磷酸钙人工骨。分别于治疗4,8,12周取下颌骨标本,免疫组织化学法观察骨形态发生蛋白2的表达,激光共聚焦显微镜观察转化生长因子β的表达。结果与结论：实验组治疗后4,8周时的骨形态发生蛋白2免疫组织化学染色阳性细胞数明显高于药物组与人工骨组,治疗后12周时实验组骨改建基本完成,骨形态发生蛋白2免疫组织化学染色阳性细胞数目低于其他两组。实验组转化生长因子β免疫荧光染色表达为逐步升高,到第8周时达到峰值,而药物组和人工骨组的转化生长因子β免疫荧光表达从4-12周一直呈上升状态,趋近于最高峰。说明雷洛昔芬能够促进自固化磷酸钙人工骨在骨缺损过程中骨形态发生蛋白的早期表达及早期骨痂的形成,加快骨缺损修复。     

A new bioactive bone cement: its histological and mechanical characterization.

We have developed a bioactive bone cement using CaO-SiO 2-P 2O 5-CaF 2 glass powders and ammonium phosphate solution, and investigated its histological and mechanical characteristics in vivo. A bone defect was drilled in proximal metaphysis of the rat tibia and filled with the bioactive bone cement in paste form or polymethylmethacrylate (PMMA) bone cement in the dough state. The cements were allowed to harden in situ. Histological examination demonstrated direct bonding between the new cement and bone by 4 weeks. The bioactive bone cement did not degrade up to 24 weeks postimplantation. The inflammatory reaction to the bioactive bone cement was less intense than the reaction induced by PMMA. Changes in the mechanical properties of the cement in vivo were studied by implanting hardened cylindrical specimens of both types of cement into the hindlimb muscles of rats for 12 weeks. The compressive strength of the bioactive cement increased significantly after implantation, and reached 68 MPa in 1 week and 73 MPa in 4 weeks. These values were comparable to those of PMMA, and were maintained up to 12 weeks after implantation. This bioactive bone cement hardens in situ within a few minutes with negligible rise of temperature and can be easily handled as a paste for filling bone cavities of different shapes. In addition, this cement has good osteoconductive and bone bonding potential and fairly high mechanical strength. Therefore, this new cement could be used both as a bioactive bone cement and bone defect filler.     

Octacalcium phosphate collagen composite facilitates bone regeneration of large mandibular bone defect in humans

Recently it was reported that the implantation of octacalcium phosphate (OCP) and collagen composite (OCP–collagen) was effective at promoting bone healing in small bone defects after cystectomy in humans. In addition, OCP–collagen promoted bone regeneration in a critical‐sized bone defect of a rodent or canine model. In this study, OCP–collagen was implanted into a human mandibular bone defect with a longer axis of approximately 40 mm, which was diagnosed as a residual cyst with apical periodontitis. The amount of OCP–collagen implanted was about five times greater than the amounts implanted in previous clinical cases. Postoperative wound healing was satisfactory and no infection or allergic reactions occurred. The OCP–collagen‐treated lesion was gradually filled with radio‐opaque figures, and the alveolar region occupied the whole of the bone defect 12 months after implantation. This study suggests that OCP–collagen could be a useful bone substitute material for repairing large bone defects in humans that might not heal spontaneously. Copyright © 2015 John Wiley & Sons, Ltd.     

A study of the bioactive bone cement--bone interface: quantitative and histological evaluation.

The interface between bone and a bioactive glass cement--a mixture of bioactive glass powder and ammonium phosphate solution, previously reported on by the authors--was evaluated quantitatively and histologically. The materials tested were (1) the original bioactive glass cement (BCI cement); (2) an improved type of bioactive glass cement (BCII cement); (3) polymethylmethacrylate (PMMA) bone cement; and (4) a bioactive, apatite-wollastonite-containing, glass ceramic (A-WGC). Hardened cylindrical specimens of each cement were inserted loosely into canine femora and the interfacial shear strengths were measured using a push-out test. The interfacial strength values of the bioactive glass cements increased with prolonged implantation time. At each postimplantation time studied (8, 12, and 24 weeks), the interfacial strength value of BCI cement did not differ significantly from that of A-WGC. BCII cement interfacial strength was greater than that of BCI cement, whereas the interfacial strength of PMMA bone cement remained at a very low level throughout the study. Histological examinations revealed that direct bonding of both bioactive glass cements to bone had occurred without pathologic degradation. After 24 weeks, the defects between the bone and the bioactive glass cements had been filled with mature lamellar bone. Because the bioactive glass cement system developed by the authors, especially BCII cement, shows excellent osteoconductivity and bonds to bone tightly, we consider it to be a promising material for fixing prostheses into bone.     

Bone regeneration in minipigs via calcium phosphate cement scaffold delivering autologous bone marrow mesenchymal stem cells and platelet‐rich plasma

Macroporous calcium phosphate cement (CPC) with stem cell seeding is promising for bone regeneration. The objective of this study was to investigate the effects of co‐delivering autologous bone marrow mesenchymal stem cells (BMSCs) and autologous platelet‐rich plasma (PRP) in CPC scaffold for bone regeneration in minipigs for the first time. Twelve female adult Tibet minipigs (12–18 months old) were used. A cylindrical defect with 10 mm height and 8 mm diameter was prepared at the femoral condyle. Two bone defects were created in each minipig, one at each side of the femoral condyle. Three constructs were tested: (1) CPC scaffold (CPC control); (2) CPC seeded with BMSCs (CPC‐BMSC); (3) CPC seeded with BMSCs and PRP (CPC‐BMSC‐PRP). Two time points were tested: 6 and 12 weeks (n = 4). Good integration of implant with surrounding tissues was observed in all groups. At 12 weeks, the CPC‐BMSC‐PRP group had significantly less residual CPC remaining in the defect than the CPC‐BMSC group and the CPC control (p < 0.05). The residual CPC volume for the CPC‐BMSC‐PRP group was half that of the CPC control. New bone formation for CPC‐BMSC‐PRP was more than two‐fold that of the CPC control (p < 0.05). CPC‐BMSC‐PRP had new blood vessel density that was nearly two‐fold that of the CPC control (p < 0.05). In conclusion, CPC scaffold with autologous BMSC‐PRP doubled the new bone regeneration and blood vessel density in minipigs compared with the CPC control. In the present study, the new macroporous CPC system with co‐delivered BMSC‐PRP has been shown to promote scaffold resorption and bone regeneration in large defects. Copyright © 2017 John Wiley & Sons, Ltd.     

活性煅烧骨复合骨水泥修复骨缺损:修复后的血管化及结构变化

目的观察活性煅烧骨(TBC)复合骨水泥(BC)修复骨缺损后的血管化及结构变化。方法将活性TBC和BC复合后植入兔尺骨缺损部位,不同时间行印度墨汁动脉血管灌注及材料断面扫描电镜观察,观察血管生成情况及结构变化。结果墨汁灌注2周时见TBC周围血管形成密集,并向材料中长入,4、8和12周时新生血管逐渐增多,并深入材料中央。电镜观察4周时TBC周围及内部孔隙被胶原纤维束充填,部分胶原矿化。8～12周新生骨组织附于TBC颗粒及BC表面,原孔隙接近消失,TBC颗粒少量降解。结论活性TBC复合BC具有骨诱导作用,新生血管及新生骨组织生成良好,是理想的骨缺损修复材料。     

多孔碳酸化羟基磷灰石水泥修复双侧股骨髁骨缺损:同体随机对照16周组织学结果验证

背景:课题组采用发泡剂成孔技术,制成了有知识产权的新型骨修复材料多孔碳酸化羟基磷灰石,既保留了碳酸化羟基磷灰石骨水泥原位固化性能等所有的优点,同时又形成多孔结构.目的:通过动物实验进一步验证制备的新型骨修复材料多孔碳酸化羟基磷灰石水泥修复骨缺损的效果.设计、时间及地点:同体对比观察实验,于2000-01/2002 08在解放军总医院骨科研究所及医学动物实验中心完成.材料:以碳酸钙、磷酸氢钙等化学试剂为原材料,通过高温烧结合成碳酸化羟基磷灰石粉体,粉体与固化液相混合原位固化形成碳酸化羟基磷灰石;在碳酸化羟基磷灰石粉体中加入成孔剂,成孔剂在骨水泥固化过程中发生化学反应产生二氧化碳气体,由此形成多孔碳酸化羟基磷灰石.方法:采用10只新西兰大白兔在双侧股骨髁制备直径为5.5 mm、深12 mm的骨缺损动物模型,随机选择侧作为实验组,调和多孔碳酸化羟基磷化石,迅速将其置于特制的注射器中,注入骨缺损.另一侧为对照组,骨缺损直接填充碳酸化羟基磷化石.主要观察指标:分别于术后2,4,8,12,16周分批处死动物.通过X射线和组织学观察其修复效果.结果:实验组骨缺损逐渐被新生骨填充,骨组织逐渐改建,趋于成熟.对照组材料的边缘区有新骨生长,并随时间呈递增趋势,材料的中央区未见新骨组织.术后16周影像学检查,实验组材料与周围正常骨的密度相当,很难区分界线,对照组材料的可视面积明显减少.结论:多孔碳酸化羟基磷灰石水泥具有原位固化性能和良好的生物相容性,能作为自体骨移植的一种替代物修复骨缺损.     

Effects of substitute coated with hyaluronic acid or poly‐lactic acid on implant fixation: Experimental study in ovariectomized and glucocorticoid‐treated sheep

Investigated in healthy animal models, hyaluronic acid (HyA) and poly‐_D,L‐lactic acid (PDLLA) demonstrate osteoconductive properties when coated onto hydroxyapatite (HA) and β‐tricalcium phosphate (βTCP) scaffolds. In this study, we examined the efficacy of HA/βTCP granules coated with HyA or PDLLA on implant fixation when applied as graft materials in 2‐mm size defects created in the femur condyles of ovariectomized (OVX) glucocorticoid‐treated (GC) sheep. Titanium alloys were inserted into the femur condyles of OVX and GC‐treated sheep, and the concentric gaps were filled with either allograft obtained from a healthy donor sheep (control), pure HA/βTCP, HA/βTCP‐HyA or HA/βTCP‐PDLLA. After 12 weeks, the bone formation adjacent to the implant surface was evaluated by histology and histomorphometry, while the implant fixation was measured by a push‐out test. The investigation showed a bone formation in the HA/βTCP‐HyA and HA/βTCP‐PDLLA groups not significantly different from allograft (p  >  0.05), whereas the HA/βTCP group revealed a significantly reduced formation of bone compared with allograft (p  <  0.05). Bone–implant contact (BIC) and mechanical properties were similar comparing HA/βTCP‐HyA and HA/βTCP‐PDLLA with allograft (p  >  0.05). This study demonstrated that bone substitutes infiltrated with PDLLA and HyA possess osteoconductive properties comparable to allograft when tested in sheep with an OVX and GC‐induced bone loss. With no significant difference in implant fixation and bone formation, HyA and PDDLA are indeed considered valuable as new coating materials for composite ceramics when tested in a sheep model – even in bones of a compromised quality.     

复合同种异体颗粒骨修复兔桡骨缺损实验研究

目的观察复合磷酸钙骨水泥同种异体微小颗粒骨修复骨缺损的效果。方法建立兔双侧桡骨中段12mm骨缺损模型，40只兔随机分为A、B、C3组，A组植入复合磷酸钙骨水泥同种异体微小颗粒骨，B组植入同种异体微小颗粒骨，C组为空白对照组。术后4周和8周分别行X线摄片、组织学观察、骨缺损修复血管化观察和生物力学测定。结果A组的骨缺损修复效果、新生骨的组织学结构和生物力学测定均优于B组，C组无骨愈合迹象。结论同种异体微小颗粒骨能较好地修复骨缺损，但复合磷酸钙骨水泥同种异体微小颗粒骨修复骨缺损的效果更佳。     

Biosilicate® and low-level laser therapy improve bone repair in osteoporotic rats

The aim of this study was to investigate the effects of a novel bioactive material (Biosilicate^®) and low‐level laser therapy (LLLT) on bone fracture consolidation in osteoporotic rats. Forty female Wistar rats were submitted to ovariectomy (OVX) to induce osteopenia. Eight weeks after surgery, the animals were randomly divided into four groups of 10 animals each: a bone defect control group (CG); a bone defect filled with Biosilicate group (BG); a bone defect filled with Biosilicate and irradiated with LLLT at 60 J/cm² group (BG60); and a bone defect filled with Biosilicate and irradiated with LLLT at 120 J/cm² group (BG120). Bone defects were surgically performed on both tibias. The size of particle used for Biosilicate was 180–212 µm. Histopathological analysis showed that bone defects were predominantly filled with the biomaterial in specimens treated with Biosilicate. LLLT with either 60 or 120 J/cm² was able to increase collagen, Cbfa‐1, VGEF and COX‐2 expression in the circumjacent cells of the biomaterial. A morphometric analysis revealed that the Biosilicate + laser groups showed a higher amount of newly formed bone. Our results indicate that laser therapy improves bone repair process in contact with Biosilicate as a result of increasing bone formation, as well as COX‐2 and Cbfa‐1 immunoexpression, angiogenesis and collagen deposition in osteoporotic rats. Copyright © 2010 John Wiley & Sons, Ltd.     

川续断复合磷酸钙骨修复骨缺损

背景：复合磷酸钙骨植入材料的物理结构和无机成分与人体骨相似,具有良好的生物可吸收性和生物相容性。研究证实续断细粉能明显提高骨缺损修复速度。 目的：观察川续断复合磷酸钙骨复合植入材料修复骨缺损的效果。 方法：在新西兰大白兔双侧下颌骨体部制备长约1.0 cm、宽约0.5 cm、深约0.3 cm的骨缺损,右侧植入川续断复合磷酸钙材料作为实验组,左侧植入磷酸钙骨材料作为对照组。植入后4,8,12周取材,进行大体观察、CBCT检测、扫描电镜、组织学观察。 结果与结论：①大体观察：实验组成骨速度、材料降解率及硬度高于对照组。②CBCT 检测：实验组材料与周围组织结合紧密度强于对照组,且材料降解速度快于对照组。③扫描电镜：两组材料与周围正常骨组织间大多由纤维结缔组织充盈,实验组比对照组更为紧密,空隙更加微小,随着时间的增加,材料与周围正常骨组织的结合更为紧密。④组织学观察：实验组成骨速度及成骨活性优于对照组。表明川续断复合磷酸钙骨植入材料具有明显加速成骨的作用。     

Comparative study of the osteogenic ability of four different ceramic constructs in an ectopic large animal model

Tissue‐engineered constructs combining bone marrow mesenchymal stem cells with biodegradable osteoconductive scaffolds are very promising for repairing large segmental bone defects. Synchronizing and controlling the balance between scaffold‐material resorption and new bone tissue formation are crucial aspects for the success of bone tissue engineering. The purpose of the present study was to determine, and compare, the osteogenic potential of ceramic scaffolds with different resorbability. Four clinically relevant granular biomaterial scaffolds (specifically, Porites coral, Acropora coral, beta‐tricalcium phosphate and banked bone) with or without autologous bone marrow stromal cells were implanted in the ectopic, subcutaneous‐pouch sheep model. Scaffold material resorption and new bone formation were assessed eight weeks after implantation. New bone formation was only detected when the biomaterial constructs tested contained MSCs. New bone formation was higher in the Porites coral and Acropora coral than in either the beta‐tricalcium phosphate or the banked bone constructs; furthermore, there was a direct correlation between scaffold resorption and bone formation. The results of the present study provide evidence that, among the biomaterials tested, coral scaffolds containing MSCs promoted the best new bone formation in the present study. Copyright © 2013 John Wiley & Sons, Ltd.     

磷酸钙骨水泥对股骨颈骨折内固定辅强作用的组织学评价

背景:将磷酸钙骨水泥作为一种内固定辅强材料可提高骨折固定的稳定性,特别是对伴有骨质疏松、骨质较脆弱的骨折可发挥长期良好的固定作用。目的:从组织学方向分析磷酸钙骨水泥对股骨颈骨折内固定的辅强作用,并同非辅强及聚甲基丙烯酸甲酯辅强进行对比评估。设计:随机对照、重复观察、开放性实验。单位:吉林大学第一医院骨科与基本外科,吉林大学基础医学院病理室,日本爱知医科大学整形外科。材料:实验于1999-01/2004-01在吉林省洮南市医院、吉林大学、日本爱知医科大学完成。选用45只成熟中国绵羊,平均年龄12.5个月,随机分成3组:非辅强组、磷酸钙骨水泥辅强组、聚甲基丙烯酸甲酯辅强组,15只/组。分别于术后3,6,12周取材,每个时间点5只/组。磷酸钙骨水泥由粉剂和固化液组成(粉剂包括75%α-磷酸三钙、18%磷酸四钙、5%磷酸氢钙和2%Hydroxyapatite;固化液包括5%sodiumchondroitinsulphate、12%sodiumsuccinate和83%水),粉液比为3∶1。聚甲基丙烯酸甲酯骨水泥包括97.4%methylmethacrylate、2.6%Ndimethyl-para-toluidine和hydroquinone。方法:①将各组绵羊采用pentobarbitalsodium静脉麻醉后,进行截骨、钻孔、攻丝和固定。截骨部位均在右股骨颈基底部,用2枚直径4mm松质骨螺钉经大转子下固定。骨水泥则在螺钉拧入前填充。②磷酸钙骨水泥辅强组向孔中注射调配好粉剂和固化液比例的磷酸钙骨水泥,聚甲基丙烯酸甲酯辅强组向孔中注射聚甲基丙烯酸甲酯骨水泥,非辅强组不给予任何材料。③各组标本首先进行最大载荷测试,然后均在40%,70%,90%,100%乙醇中梯度脱水、染色、聚甲基丙烯酸甲酯包埋。最后用锯切片机沿股骨颈方向连续切片,厚度为150～200μm。硬组织切片在接触显微X线照相机上进行拍摄,分别于术后3,6,12周显微镜下观察各组标本骨水泥周围新骨形成情况及宿主骨的改变。主要观察指标:术后不同时间各组骨水泥周围新骨形成情况及宿主骨的变化。结果:实验选用45只成熟中国绵羊,全部进入结果分析。术后不同时间各组骨水泥周围新骨形成情况及宿主骨的变化:①非辅强组:术后3周在螺钉周围产生少量纤维组织,且宿主骨骨床有显微破坏,但显微破坏在术后6及12周时可见修复。②磷酸钙骨水泥辅强组:术后3,6,12周磷酸钙骨水泥充满于螺钉和宿主骨之间,而且磷酸钙骨水泥表面有新骨形成,在新骨和磷酸钙骨水泥之间没有纤维组织介入。在术后12周可见大量新骨形成,且见许多骨小管。③聚甲基丙烯酸甲酯辅强组:术后3周在骨床与聚甲基丙烯酸甲酯之间产生大量纤维组织,可见明显骨吸收,术后6及12周尤为明显。结论:由于磷酸钙骨水泥具有良好的组织相容性、骨传导性及自身改建能力,因此对股骨颈骨折提供了长期有益的辅强作用。     

复合材料修复骨缺损血管化及结构特征变化

ThelecturesaboutcarriermaterialsofBMP（bonemorphogeneticprotein）areveryusual．ThecompoundmaterialscombinedwithBMPshouldhavefinemoldingability，biomechanicsandboneinductivecapability．Bonecementhasbeenusedwidespreadinartificialjointsurgery．WeusethecompoundmaterialofDBM（decalcifiedbonematrix）particleswhichwascombinedwithrhBMP－２（recombinedhumanbonemorphogeneticprotein）impregnatedwithbonecementtorepairtherabbitbonedefectandstudythechangesofcirculationandconstructionofthecompoundmateri…     

医用硫酸钙与磷酸钙在创伤性骨缺损中的应用比较

背景：自体骨移植、异体骨移植、异种骨移植的来源缺乏,或存在免疫反应与感染和再骨折的可能。而作为人工骨替代物,硫酸钙和磷酸钙在临床上的使用比较广泛。目的：拟比较人工合成医用硫酸钙和磷酸钙在骨创伤中作为骨替代物的临床使用效果。设计、时间及地点：随机对照观察,于2004-10/2007-10在中国中医科学院西苑医院骨科完成。对象：选择50例骨创伤后存在不同程度的骨缺损并需要植骨的患者,在无自体骨混用的情况下,按随机数字表达分为2组,分别使用了不同类型的人工骨进行骨缺损填充,其中硫酸钙骨空腔填料组24例,磷酸钙生物陶瓷组26例。方法：治疗除采用内固定（钢针、钢板）和外固定（石膏、外固定架）外,分别结合使用硫酸钙骨空腔填料及磷酸钙生物陶瓷。植入的人工骨量以植骨术中判断为准,桡骨远端骨折和跟骨骨折一般植入3～5mL,最大植入量为10mL。植入人工骨要尽可能填满充实。主要观察指标：人工骨替代物使用量、吸收时间、骨折是否稳定以及骨痂出现的时间。结果：所有使用填充人工骨的病例,骨折均如期愈合,使用硫酸钙者未出现任何异常反应和并发症,使用磷酸钙者有2例浅表渗出,经换药愈合。平均随访6个月,硫酸钙组平均吸收时间较磷酸钙组短,硫酸钙组2个月内吸收80%,3个月内100%吸收;磷酸钙组4～6个月吸收70%,7～12个月吸收90%。结论：医用硫酸钙和磷酸钙人工骨均可作为骨替代物应用,在辅助固定下具有安全、方便、副作用小以及填充效果确实、骨折愈合良好等优点。硫酸钙骨粉固化后较磷酸钙坚固,具有较强的支撑作用,且降解速度较磷酸钙快。     

Unique and reliable rat model for the assessment of cell therapy: bone union in the rat mandibular symphysis using bone marrow stromal cells

Many kinds of bone graft materials have been developed and reported to repair various bone defects. The defects are usually created by surgical resection of pre‐existing bone tissue. However, spontaneous healing of bone defects without implantation of materials could be seen, because bone tissue possesses inherent repairing property. The central portion of the lower jaw bone in many animals consists of fibrous tissue and is called the mandibular symphysis. It persists even in old animals and thus can be interpreted as a physiological bone gap or a non‐healing bone defect. We implanted calcium phosphate porous ceramics alone or composites of the ceramics and bone marrow stromal cells (BMSCs) into the bone defect (mandibular symphysis) to examine whether it could be filled with new bone tissue, resulting in bone union. Eight weeks after implantation, micro‐computed tomography (micro‐CT) and histological and biomechanical analyses demonstrated that bone union of the mandibles occurred in all rats with composites but in none of those with ceramics alone. These results showed that the rat mandibular symphysis is a unique bone defect site for the evaluation of bone graft materials. These analyses demonstrated that ceramics alone could not contribute to bone healing in the defect; however, supplementation with BMSCs drastically changed the properties of the ceramics (turning them into osteogenic ceramics), which completely healed the defect. As BMSCs can be culture‐expanded using small amounts of bone marrow, the use of the composites might have clinical significance for the reconstruction of various bone tissues, including facial bone. Copyright © 2012 John Wiley & Sons, Ltd.     

High‐intensity Nd:YAG laser accelerates bone regeneration in calvarial defect models

High‐power pulsed lasers have been recently regarded to be anabolic to bone, but in vivo evidence is still lacking. This study aimed to investigate the capacity of bone repair using a high‐power, Q‐switched, pulsed, neodymium‐doped yttrium aluminium garnet (Nd:YAG) laser, using bilateral calvarial defect models having non‐critical sized, 5 mm (rat) or 8 mm (rabbit) diameter. One of the bilateral defects, which were all filled with collagen sponge or left empty, was irradiated with a Nd:YAG laser once every 2 days for 2 weeks at a constant total fluence rate (344 J/cm²), output power (0.75 W), pulse repetition rate (15 pps) and wavelength (1064 nm) and examined for the laser effect. The same experimental scheme was designed using a rabbit calvarial defect model implanted with sponge, which was explored for the dose effect of output power at 0.75 and 3 W with the same quantities of the other parameters. New bone formation was evaluated by micro‐computed tomography‐based analysis and histological observation at 4 weeks after surgery. Laser irradiation significantly increased new bone formation by approximately 45%, not only in the sponge‐filled defects of rats but also when the defects were left empty, compared to the non‐irradiated group. Consistently, both doses of output power (0.75 and 3 W) enhanced new bone formation, but there was no significant difference between the two doses. This study is one of the first to demonstrate the beneficial effect of Nd:YAG lasers on the regeneration of bone defects which were left empty or filled with collagen sponge, suggesting its great potential in postoperative treatment targeting local bone healing. Copyright © 2013 John Wiley & Sons, Ltd.     

富血小板纤维蛋白联合自固化型磷酸钙人工骨修复颌骨缺损

背景:Choukroun富血小板纤维蛋白与自固化型磷酸钙人工骨都具有促进骨缺损修复的能力,但单独应用均有其不足,两种材料结合使用是否会达到理想效果?目的:观察Choukroun富血小板纤维蛋白联合自固化型磷酸钙人工骨在颌骨缺损修复中的作用。方法:将40例颌骨缺损患者随机分组:实验组缺损骨腔用Choukroun富血小板纤维蛋白联合自固化型磷酸钙人工骨充填,对照组缺损骨腔只充填自固化型磷酸钙人工骨。结果与结论:实验组治疗后1个月颌骨缺损区与周围颌骨有分界,有新骨开始形成;治疗后3个月,新骨与周围颌骨间的界限模糊不清,缺损区骨密度开始增加,有大量骨小梁形成;治疗后6个月缺损区与周围正常骨界限不清,开始出现正常骨质形态。对照组治疗后6个月新生骨与周围正常骨之间有明显界限,且缺损区骨腔内骨密度均低于同期实验组骨缺损区骨密度(P<0.05)。表明Choukroun富血小板纤维蛋白联合自固化型磷酸钙人工骨治疗颌骨缺损可明显促进骨组织生长。