柠檬酸钙在体外条件下对新鲜血液影响的实验研究

目的探讨柠檬酸钙在体外条件下对新鲜血液的影响。方法测量加入柠檬酸钙后新鲜血液中红细胞的溶血率;分别向2 m L血清中加入柠檬酸钙0 mg、1.0 mg、2.0 mg、3.0 mg、4.0 mg、5.0 mg、6.0 mg、7.0 mg、8.0mg、9.0 mg、10.0 mg和12.0 mg后测量血清中钙离子浓度,在此实验基础上,把实验分为四组,向5 m L新鲜血液中分别加入柠檬酸钙0 mg,1.0 mg,5.0 mg和9.0 mg后分别测量血液凝固前血清钙浓度、血液凝固后血清钙浓度、凝血块体积、凝血时间,测算单位体积凝血块中的钙浓度。结果柠檬酸钙具有良好的血液相容性,加入柠檬酸钙后新鲜血液中血清钙离子浓度增加,单位体积血凝块中的钙含量有统计学差异(0.01),新鲜血液凝血时间延长。结论柠檬酸钙具有良好的生物相容性,加入新鲜血液中能够为骨折愈合提供适宜的钙离子浓度,柠檬酸钙溶解的钙离子能储存在凝血块中,可为骨折愈合后期提供所需的钙离子,柠檬酸钙作为骨生物材料具有良好的应用前景。     

联合钙盐骨水泥及可降解网状微孔球囊椎体成形的体外实验

背景：椎体成形、椎体后凸成形治疗骨质疏松性椎体压缩性骨折中存在骨水泥外溢、伤椎及临近椎体继发骨折等风险。 目的：验证高分子可降解网状微孔球囊应用于骨质疏松性椎体压缩骨折的可行性。 方法：以聚乳酸-已内酯共聚物为原材料,采用静电纺丝技术制备可降解网状微孔球囊,同时制备涂层球囊,扫描电镜观察其形貌;向球囊内分别注入水和骨水泥,观察外渗情况;测试球囊的断裂强度和断裂伸长率。采用细胞染色法和CCK-8法测试小鼠胚胎成骨细胞在两种球囊上的增殖情况。观察两种球囊在模拟体液、猪胰脂肪酶溶液和新鲜的人血清中的降解。将球囊置入猪椎体后测试球囊的爆破压。将钙盐骨水泥注入球囊后密封,固化后置于6 atm压力的超纯水中,定期检测钙离子浓度。 结果与结论：网状微孔球囊具有良好的纤维形态,粗细分布均匀,存在孔隙;涂层球囊表面无具体形态结构及孔隙存在。与涂层球囊相比,网状微孔球囊具有更好的力学性能和液体渗透性及爆破压力,可防止骨水泥渗漏,促进成骨细胞的黏附与增殖,降解更均匀、稳定,可较好保持钙离子浓度,更利于新骨生长和骨折愈合。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

生物降解材料复合成骨因子在骨科应用研究中的进展

背景：生物可降解植入物不仅可重建骨缺损部位,而且随着材料的逐步降解,新生骨组织可完全替代移植材料,填充骨缺损处。目的：总结生物降解材料复合成骨因子在骨科的研究进展。方法：以“可降解材料,成骨因子,细胞活性因子,骨组织工程;Biodegradable materials,factors,cell active factor,bone tissue engineering”为检索词,应用计算机检索PubMed、万方、CNKI数据库2000至2015年的相关文献。结果与结论：生物可降解医用高分子材料可分为天然高分子材料和人工合成可降解材料。天然高分子材料具有良好的生物相容性,但其机械强度较差;人工合成可降解材料械强度较天然高分子材料高,但容易造成局部酸性物质堆积,产生局部炎症反应。将生物可降解医用高分子材料与成骨因子复合,可提高材料的力学强度与骨诱导能力,但将其作为骨修复材料应用于临床还有很多问题需要解决。  中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

可吸收缝线材料的可降解与临床应用

背景：由于可吸收缝合线具有良好的生物相容性及机械强度,在临床被广泛应用。 目的：探讨不同可吸收性缝线的体外降解性能,分析可吸收缝合线临床应用中的优势及其体外降解行为的影响因素。 方法：通过检索近年来文章内容与可吸收缝线材料降解性能和应用相关的文献,从可吸收缝线材料的性能及降解行为影响因素、可吸收与不可吸收缝合线临床应用比较等对可吸收缝线材料相关研究成果作回顾性分析,为临床提供理论依据。 结果与结论：可吸收缝合线体可被机体完全降解吸收,无不良反应,创口愈合后不留瘢痕,克服了不可吸收缝合线不能在体内分解的缺点,其降解产物的体内吸收主要有2个途径：一为体内巨细胞与吞噬细胞吞噬,另一途径为降解产物进入人的体液与血液,如乳酸通过体循环被吸收排泄。人体内有一个极其复杂的生理环境,存在着影响材料性能的各种因素。加之材料的种类不同,它们在体内的降解行为也不尽相同,因此需要在一定范围内设计合成和加工出具有特殊性能的可降解高分子材料满足临床需要。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

生物止血材料医用胶黏合儿童额面部开放性伤口创面的可行性

背景：生物止血材料医用胶在体液、血液作用下的扩散性好,可迅速发生聚合反应,产生较理想的止血、促进愈合等作用。 目的：观察医用胶作为止血材料在儿童额面部开放性伤口创面中的临床应用价值。 方法：选择以生物材料医用胶黏合额面部开放性伤口的1 218例儿童为观察组,以常规丝线缝合额面部开放性伤口的600例儿童为对照组,比较两组伤口愈合时间、术后伤口出血情况、缝线反应、色素沉着情况及瘢痕增生程度。 结果与结论：观察组手术时间、出血量及伤口愈合时间均少于对照组(P < 0.05),有效止血率高于对照组(P < 0.05);观察组中1 215例伤口Ⅰ期愈合,对照组中586例伤口Ⅰ期愈合。随访12个月,观察组瘢痕愈合平整,无线结瘢痕及针眼瘢痕,与临近皮肤肤色相近,美容效果良好;对照组瘢痕较明显,可见线结瘢痕及针眼瘢痕,大部分伤口周围出现红斑、硬结及瘢痕增生。使用生物止血材料医用胶黏合儿童额面部开放性伤口具有良好的生物相容性及美容效果,且使用安全、方便。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程      

两种不同材料外固定器修复胫骨骨折：新型PEEK复合材料外固定器更有优势

背景：胫骨骨折传统外固定存在明显应力遮挡,骨折延迟愈合不愈合,聚醚醚酮树脂(polyetheretherketone,PEEK)材料弹性模量接近骨质,将有可能解决这一临床难题。 目的：比较胫骨骨折采用新型PEEK复合材料外固定器和传统材料外固定器外固定治疗效果。 方法：回顾分析胫骨骨折86例,男64例,女22例;年龄24-78岁,平均56岁;闭合性骨折30例,开放性骨折56例;平诊手术32例,急诊手术54例。所有患者根据外固定方法不同分为2组,分别采用新型PEEK复合材料外固定器和传统材料外固定器治疗。固定后定期复查X射线片,末次随访时根据Johner-Wruhs胫骨干骨折疗效评价标准评定功能恢复情况。 结果与结论：所有患者固定后均获5-20个月随访。PEEK组平均8.7周拆除外固定器,4.2个月骨折愈合;传统材料外固定器平均10.6周拆除外固定器,6.1个月骨折愈合。末次随访时根据Johner-Wruhs胫骨干骨折疗效评价标准评定功能恢复情况：PEEK组优26例,良 13例,差 4例;传统材料外固定器优 19例,良13例,差11例。结果表明,应用PEEK复合材料外固定器治疗不同类型胫骨骨折较传统材料外固定器治疗具有可保持骨折稳定、促进骨折愈合、利于患肢功能恢复的优势。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

天然牡蛎壳纳米体复合型骨材料修复骨缺损

背景：研究发现,牡蛎壳等很多海洋生物外壳等形成矿物质盐的过程与人体实际情况较为接近。 目的：观察天然牡蛎壳纳米体复合型骨材料修复骨缺损的效果。 方法：取30只成年大耳白兔,制作双侧桡骨骨缺损模型,随机均分为两组,实验组于骨缺损处植入天然牡蛎壳纳米体复合型骨材料,对照组于骨缺损处植入医用硫酸钙可注射型植骨材料,植入后2,8,12周进行X射线检查,了解植入骨材料周围组织生长结合情况;于第12周末获得双侧桡骨,利用生物力学测试系统检测桡骨抗弯曲强度,并利用彩色图像分析仪定量分析成骨情况。 结果与结论：植入后2周,两组骨材料密度较周边正常骨组织呈偏低,缺损与材料间边界清晰,未发现明显骨修复现象;植入后8周,两组骨材料均被较厚软组织全部包裹,实验组血管成分显著减少;植入后12周,两组骨材料紧密结合相邻组织,包裹骨材料的组织质地较韧,二者之间无界线,实验组桡骨表面形态已恢复至正常水平,在形态和质地结构方面与正常组织无明显区别,对照组仍存在明显投射分界影像。实验组桡骨抗弯曲强度和成骨量均显著大于对照组(P < 0.05)。表明天然牡蛎壳纳米体复合型骨材料修复骨缺损可以获得更好的桡骨抗弯曲强度,并促进新骨形成。     

固骼生材料修复四肢骨折骨缺损：植骨融合效应

背景：新型骨修复材料固骼生具有独特的生物活性和良好的生物相容性,临床修复骨缺损可以发挥出良好的键合性,有效促进软组织及骨组织的键合。 目的：分析固骼生材料修复四肢骨折所致骨缺损的临床效果。 方法：纳入67例四肢骨折致骨缺损患者,其中男37例,女30例,年龄17-81岁,均实施固骼生材料修复治疗。修复后3 d,检测血常规、心肾功能及血清学补体C3、补体C4、免疫球蛋白G、免疫球蛋白A、免疫球蛋白M等水平;修复后随访12个月,X射线观察植骨融合效果。 结果与结论：所有患者切口均一期愈合,未出现切口感染病例,各项实验室指标未见明显异常,未发生任何排斥和非特异炎症反应,植骨区未出现不适感或者异常症状;随访12个月,所有患者骨折均呈骨性愈合,植骨不融合1例,可能不融合1例,不确定融合2例,可能融合33例,坚强融合30例,植骨融合率为94%。表明采用固骼生材料修复四肢骨折所致骨缺损具有良好的生物相容性,修复效果良好,植骨融合率高。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

生物活性玻璃与壳聚糖复合的骨修复材料

背景：生物活性玻璃是一种多相复合材料,具有良好的生物活性、骨传导性及生物相容性,但作为骨修复材料仍然存在不能完全降解、机械强度较低等不足。 目的：设计生物活性玻璃/壳聚糖复合材料骨组织工程支架,并检测其理化性能。 方法：将2.0%壳聚糖盐酸溶液与β-甘油磷酸钠以7∶1的体积比混合制备壳聚糖溶液。称取0.5,1.0,1.5 g生物活性玻璃分别加入上述壳聚糖溶液中,使得壳聚糖与生物活性玻璃的质量比为2∶1,1∶1及1∶1.5。将复合材料浸泡于模拟生理体液中7 d进行体外矿化。 结果与结论：扫描电镜见复合支架具有相互贯通的多孔结构,孔隙率最高可达89%,孔径大小合适,为100-  300 µm,生物活性玻璃以针状形式分散在壳聚糖支架之间,均匀排列,被壳聚糖支架充分包裹结合紧密。随生物活性玻璃含量的增加,复合材料的孔隙率逐渐下降,断裂强度逐渐升高,他们之间呈正相关性。X射线衍射图及傅里叶变换红外光谱证实复合支架中的单一材料未发生性质改变,示差扫描量热法分析显示正常体温情况下材料无质量丢失。矿化3 d后材料表面形成的羟基磷灰石逐渐长大为绒毛状,数量也明显增多;矿化7 d后绒毛状的羟基磷灰石长成为针状,数量进一步增多,且众多的矿化物结成球状。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

双相钙磷生物陶瓷/硫酸钙骨水泥多孔三维支架的生物性能

背景：随着组织工程技术的发展,多孔生物陶瓷被越来越多的运用到骨缺损的修复中,当前的研究主要集中在这种生物陶瓷的合成及其各项性能的评价。 目的：研究一种新型骨水泥的制备方法并测定其理化性能及与成骨细胞的生物相容性。 方法：共沉淀法制备双相钙磷生物陶瓷粉体,利用胶体团聚成颗粒,烧结后得到颗粒状、多孔羟基磷灰石/磷酸三钙生物陶瓷,并按不同比例与高纯度医用半水硫酸钙混合制备钙磷陶瓷/硫酸钙骨水泥。 结果与结论：X射线衍射证实合成物质为双相钙磷陶瓷,颗粒状双相钙磷陶瓷具有多孔网状结构,骨水泥在   3 min内保持可塑状态,固化时间为15 min,固化温度为36.5 ℃,压缩强度最高为5.82 MPa,MTT毒性级为0级,成骨细胞在材料表面生长良好。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

Efficacité et performance des substituts osseux pour remplacer les allogreffes et autogreffes

Although bone tissue possesses the capacity for regenerative growth, the bone repair process is impaired in many clinical and pathological situations. For example massive bone loss caused by trauma and tumor resection as well as deformities require reconstructive surgery. In this context, there was a critical need to develop implant technologies to promote bone healing. Cortical and cancellous bone grafts are the materials of choice for bone filling or reconstruction, but their clinical use involves some difficulties. Septic complications, viral transmission and unavailability of native bone have therefore led to the development of synthetic bone substitutes. Allograft bone, or tissue harvested from a cadaver, while more readily available, may carry with it the risk of disease transmission and is also difficult to shape [1–3]. A significant additional limitation of allograft bone is the delayed remodeling by the host. In the case of very large defects, the allograft may remain in the implant site throughout the patient's life, creating an area more prone to fracture or infection. The development of calcium phosphate ceramics and other related biomaterials for bone graft involved a better control of the process of biomaterials resorption and bone substitution. Synthetic bone graft materials available as alternatives to autogeneous bone for repair, substitution or augmentation, in particular synthetic biomaterials include, special glass ceramics described as bioactive glasses; calcium phosphates (calcium hydroxyapatite, HA; tricalcium phosphate, TCP; and biphasic calcium phosphate, BCP). These materials differ in composition and physical properties from each other and from bone; and must be take in consideration for more efficient bone ingrowth at the expense of the biomaterials and to adapt to new development of dedicated biomaterials. In the last decade synthetic calcium phosphate materials, principally calcium hydroxyapatite (HA) ceramics, was commercially used. However the concept of bioactivity (release of ions of biological interest) well described for glass ceramic was not particularly take in account for HA and other related biomaterials(ACP Amorphous Calcium Phosphate, CdA Calcium Phosphate deficient Apatite). HA until recently was considered to be non able to be resorbed. Calcium phosphate biomaterials differ in their solubility or extent of dissolution: ACP > > α-TCP > > β-TCP > CdA > > ACP. These ceramics are osteoconductive (act as a support for new bone formation requiring the presence of porosity) and able to be resorbed (degradable through chemical and cellular processes). They are also biocompatible (do not induce adverse local tissue reaction, immunogenicity or systematically toxicity); and more recently, some papers report osteoinductive properties associated to the chemical nature (biphasic Ca P) and the microstruture. Past decade, these bioceramics have been marketed and approved for use in humans as bone substitutes. Various presentations are currently used in orthopaedic and maxillo-facial surgery such as wedges, blocks or granules. Owing to their bone substitution properties, CaP ceramics have naturally been considered as a potential matrix for tissue engineering and the development of a bioactive drug delivery system (DDS) in bone sites. The paper presents the current knowledge on Calcium phosphate bioceramics, Bone tissue engineering and Calcium Phosphate Drug Delivery.     

Self-setting properties and in vitro bioactivity of calcium sulfate hemihydrate-tricalcium silicate composite bone cements

Self-setting biomaterials are widely used for tissue repair and regeneration. Calcium sulfate hemihydrate has been used for many years as a self-setting biomaterial due to its good setting properties. However, too fast a degradation rate and lack of bioactivity have limited its application in orthopaedic field. Herein, tricalcium silicate was introduced into calcium sulfate hemihydrate (CaSO₄ · 1/2H₂O) to form a calcium sulfate hemihydrate-based composite, and its behavior as a cement was studied in comparison with pure calcium sulfate hemihydrate. The results indicated that the workability and setting time of the composite pastes are higher than those of pure CaSO₄ · 1/2H₂O, and the composite pastes showed much better short- and long-term mechanical properties than those of pure CaSO₄ · 1/2H₂O. Moreover, the biphasic specimens showed significantly improved bioactivity and degradability compared with those of pure CaSO₄ · 1/2H₂O, indicating that the composite cements might have a significant clinical advantage over the traditional CaSO₄ · 1/2H₂O cement.     

Prenatal effects of natural calcium supplement on Wistar rats during organogenesis period of pregnancy

The potential of oral exposure to calcium and magnesium citrate, a natural product obtained from dolomite, to initiate teratogenesis was analyzed in Wistar rats. Animals received calcium and magnesium citrate oral doses of 250, 500 and 1000 mg/kg during the period of gestation from day 6 to 17 post conception. Maternal, embryo and fetal toxicity was evaluated. Calcium and magnesium citrate exposure did not produce maternal toxicity assessed by clinical observations, body weight gain, food intake, hematology, biochemical parameters and necropsy finding. Signs of embryo–fetal toxicity were not observed. Skeletal and visceral malformations were seen occasionally in all drug-treated and control groups. Skeletal and visceral variations were similar in control and drug-treated groups except for incomplete ossification rib. These finding was spontaneous and unrelated to the drug. In conclusion, in this study we found that the oral exposure to rats of up to 1000 mg/kg of calcium and magnesium citrate during organogenesis did not induce significant maternal and embryo–fetal toxicity. The experimentally derived NOAEL for developmental toxicity was 1000 mg/kg.     

磷酸钙生物材料固有骨诱导性的研究现状与展望

磷酸钙陶瓷因与骨的无机组成相似,具有良好生物相容性和骨引导性,无抗原性,被广泛应用于骨缺损修复,但一直认为磷酸钙陶瓷是一类仅具有骨引导性,而无骨诱导性的生物活性材料。大量研究表明通过材料自身组成和结构优化,可赋予磷酸钙陶瓷骨诱导性。本文对磷酸钙骨诱导现象发现和确证、骨诱导过程和机制、影响骨诱导性的材料学因素和骨诱导与动物种属关系、骨诱导相关的间充质细胞来源、以及骨诱导性材料的应用研究现状进行综述,并对磷酸钙生物材料骨诱导性及相关的研究方向予以展望。     

基于柠檬酸合成的新型可降解螺钉影像学和组织学的研究

目的从影像学、组织学评估聚柠檬酸复合纳米羟基磷灰石(POC-Click-HA)可吸收螺钉治疗比格犬股骨外髁骨折的适用性及其作用机制。方法健康成年比格犬9只,制备双侧股骨外髁骨折(AO分型33.B1型)模型。右侧采用POC-click-HA可吸收松质骨螺钉固定,为实验组;左侧采用聚消旋乳酸PDLLA可吸收松质骨螺钉固定,为对照组。术后4周、8周及12周分别取材行Micro-CT扫描及骨组织学染色分析。并体外观察三羧酸循环抑制剂CPI-613和外源性柠檬酸对MC3T3-E1细胞成骨作用的影响。结果Micro-CT显示术后4周POC-click-HA螺钉与骨组织结合弱于PDLLA螺钉;8周两组螺钉与周围骨组织逐渐整合,差异不明显;12周两组螺钉-骨组织均键合良好,新形成的骨小梁围绕螺钉螺纹生长。组织学染色发现:实验组螺钉周围逐渐形成新生骨,螺钉在降解,有新骨长入;而对照组螺钉周围仍有较多胶原纤维,仅见少量新骨,螺钉毫无降解。细胞培养结果显示加入CPI-613后培养基内内源性柠檬酸显著减少;抑制剂浓度越高,ALP染色阳性细胞形成数量越少;柠檬酸浓度越高,钙结节形成越多。结论POC-click-HA骨螺钉较PDLLA骨螺钉具有更强骨诱导能力和更快骨降解性,适于治疗比格犬股骨外髁骨折。柠檬酸材料促进骨折愈合的机制可能与促进成骨细胞分化有关。     

口腔科氢氧化钙制剂的临床应用评价

BACKGROUND: Calcium hydroxide has been used widely in clinical dental field, and its physical properties and bio-safety become more excellent along with the development of material science. OBJECTIVE: To summarize the physical properties, bio-safety and clinical application of calcium hydroxide materials. METHODS: A computer-based online research was performed in PubMed and CNKI databases using the keywords of “calcium hydroxide, calcium hydroxide preparation” in English and in Chinese, respectively, to retrieve relevant articles published from January 2010 to January 2016. RESULTS AND CONCLUSION: Calcium hydroxide preparation can be respectively divided into mono-component and bio-component, chemical curing and light curing, as well as power form and paste form according to its components, curing form and characteristics. Calcium hydroxide preparation has good physicochemical properties that can be used for dental root canal, root canal filling, direct pulp capping, indirect pulp capping, vital pulpotomy, and apexification. Clinical evaluation and experimental research have confirmed that the calcium hydroxide preparation has good biological safety and clinical effects; however, some urgent problems still need to be studied in depth.      

Modelling of fracture behaviour in biomaterials

One of the most frequent causes of degradation and failure of quasi-brittle biomaterials is fracture. Mechanical breakdown, even when not catastrophic, is of particular importance in the area of biomaterials, as there are many clinical situations where it opens the path for biologically mediated failures. Over the past few decades the materials/biomaterials community has developed a number of numerical models, but only with limited incorporation of brittle failure phenomena. This article investigates the ability of a non-linear elastic fracture mechanics (NLEFM) model to reliably predict failure of biomaterials with a specific focus on the clinical settings of restorative dentistry. The approach enables one to predict fracture initiation and propagation in a complex biomechanical status based on the intrinsic material properties of the components. In this paper, we consider five examples illustrating the versatility of the present approach, which range from the failure of natural biomaterials, namely dentine and enamel, to a restored tooth, a three unit all ceramic bridge structure and contact-induced damage in the restorative layered materials systems. It is anticipated that this approach will have ramifications not only to model fracture events but also for the design and optimisation of the mechanical properties of biomaterials for specific clinically determined requirements.     

In vitro osteogenetic activity of pearl

In vivo and in vitro studies have shown that shell nacre and hydroxyapatite (HA) are promising bioactive materials for bone repair. In this work, the osteogenetic activity of pearl is evaluated by soaking it in simulated body fluid (SBF) and cell culture, taking shell nacre and HA as control materials at the same time. After soaking in SBF, HA particles were rapidly formed on the surface of pearl, the dissolution of CaCO3 and the binding between organic components and Ca2+ ions in pearl provide favorable conditions for the HA precipitation, and the whole process follows a dissolution-binding-precipitation mechanism. Calcium surplus, not conventional calcium deficiency, is found in HA crystal structure; it implies that type B-HA is formed on pearl surface in this study. HRTEM observation shows that HA is poorly crystallized with so many dislocations and shuttle-like amorphous areas. Cell culture reveals that pearl could stimulate osteoblast proliferation, which proceeded more quickly and smoothly than that on shell nacre and HA, and abundant extracellular matrix occupied the whole pearl surface by 5 days. It is concluded that pearl is a superior osteoinductive material with high osteogenetic activity.     

应力条件下微小骨折块的愈合

背景：应力刺激可以促进四肢长骨干骨折愈合。 目的：观察应力因素对微小骨折块愈合的影响。 方法：制作兔双侧股骨大转子劈裂撕脱微小骨折模型,一侧采用克氏针固定(对照组),另一侧采用拉力螺钉置入固定(实验组)。 结果与结论：①X射线表现：实验组骨痂生长速度较对照组快,外骨痂量多,灰度高,骨痂塑型时间短。②CT表现：实验组内外骨痂生长速度比对照组要快,骨折处塑形较对照组好。③骨痂组织切片光镜观察发现,两组骨折愈合都表现为软骨内成骨方式,实验组血肿消失、机化较快,修复性纤维组织较早被软骨性骨痂取代,骨痂生长旺盛,断端骨痂愈合早且快,而且软骨性骨痂骨化、骨样小梁转化为编织骨均较对照组早,骨改建塑型亦较对照组好。④实验组和对照组骨折间隙内骨痂钙、磷元素的含量术后均逐渐升高至6周后开始下降,4周时实验组钙磷含量指标明显高于对照组(P < 0.01)。表明微小骨折块的愈合方式表现为软骨内成骨,适宜的加压固定较不加压固定骨折块周围组织水肿消退快,炎性反应小,骨痂中钙磷沉积早,含量大,骨折愈合时间短,骨痂质量好塑型快。