镍钛记忆合金环抱器治疗多发性肋骨骨折的临床研究

目的：探讨镍钛记忆合金环抱器治疗多发性肋骨骨折的疗效。方法100例多发性肋骨骨折患者均采用镍钛记忆合金环抱器行手术治疗。结果患者均无感染,骨折不愈合及内固定松动、滑脱等并发症发生;术后5个月~12个月取出内固定,骨折部位无炎症反应,心肺功能恢复较好。结论镍钛记忆合金环抱器呈现出良好的组织相容性,手术操作简便、创伤小、并发症少,是一种较为理想的治疗多发性肋骨骨折的方法。     

计算机辅助设计与制作技术在眼眶爆裂性骨折治疗中的应用及疗效评价

背景 眼眶爆裂性骨折引起明显的眼球形态和功能的异常.眼眶解剖结构复杂,故眼眶骨折修复手术中植入物的设计和制作具有一定的难度,而计算机辅助设计与制作(CADM)技术有望提供一种新的方法,但其临床应用价值有待评估.目的 研究CADM技术在眼眶爆裂性骨折治疗中的应用方法,评价其临床效果.方法 对河南省眼科研究所河南省立眼科医院2006年7月至2012年7月收治的眼眶爆裂性骨折患者74例74眼的手术过程和疗效进行回顾性分析,其中CADM手术者58例58眼,非CADM手术者16例16眼,2个组间患者基线特征,如年龄、性别和眼别均匹配.CADM手术组术眼采用CADM技术进行个体化三维立体植入物的设计和制作并进行眶骨骨折缺损处的填充,非CADM手术组术眼采用常规羟基磷灰石人工骨或多孔聚乙烯高分子合成材料(Medpor)填充法.所有术眼术前均行常规眼部检查以及CT检查,术后随访22～69个月,在随访期间内定期进行眼部临床观察和CT检查.观察指标包括最佳矫正视力、眼球突出度、眼球位置、眼球运动和复视改善情况以及并发症情况.结果 CADM手术组和非CADM手术组术眼术前最佳矫正视力分别为0.71±0.37和0.69±0.41,术后最佳矫正视力分别为0.74±0.38和0.72±0.41,组间差异无统计学意义(F分组=0.043,P=0.837),术眼手术前后视力的总体比较差异有统计学意义(F时间=13.576,P＜0.01),其中2个组术眼术后视力均好于术前,差异均有统计学意义(均P＜0.05).2个组间复视和眼球运动障碍治愈和好转的眼数分布差异均无统计学意义(Z=-0.298,P=0.766;Z=-0.548,P=0.584).CADM手术组和非CADM手术组术眼术前眼球眼球内陷度值分别为(3.93±0.99) mm和(3.88±0.97)mm,术后分别为(0.91±0.67)mm和(1.84±0.80)mm,组间总体比较差异无统计学意义(F分组=3.558,P=0.063),各组术眼术后眼球眼球内陷度值均明显低于术前,差异均有统计学意义(均P＜0.05).CT影像显示,CADM手术组术眼植入物在位,与眶骨骨折缺损处贴合良好,患者眼球位置及外观均恢复正常.非CADM手术组术眼发生植入物翘起并损伤内直肌.随访期内CADM手术组未发现组织感染、排斥反应等不良反应.结论 CADM技术用于眼眶爆裂性骨折的治疗可重建三维立体骨性眼眶,并有效改善患眼位置、眼球运动功能和视觉功能,其疗效优于传统植入物填充术.     

Acute and subchronic oral toxicity studies in rats with nanoscale and pigment grade titanium dioxide particles

Data generated using standardized testing protocols for toxicity studies generally provide reproducible and reliable results for establishing safe levels and formulating risk assessments. The findings of three OECD guideline-type oral toxicity studies of different duration in rats are summarized in this publication; each study evaluated different titanium dioxide (TiO₂) particles of varying sizes and surface coatings. Moreover, each study finding demonstrated an absence of any TiO₂ -related hazards. To briefly summarize the findings: 1) In a subchronic 90-day study (OECD TG 408), groups of young adult male and female rats were dosed with rutile-type, surface-coated pigment-grade TiO₂ test particles (d₅₀ = 145 nm − 21% nanoparticles by particle number criteria) by oral gavage for 90 days. The no-adverse-effect level (NOAEL) for both male and female rats in this study was 1000 mg/kg bw/day, the highest dose tested. The NOAEL was determined based on a lack of TiO₂ particle-related adverse effects on any in-life, clinical pathology, or anatomic/microscopic pathology parameters; 2) In a 28-day repeated-dose oral toxicity study (OECD TG 407), groups of young adult male rats were administered daily doses of two rutile-type, uncoated, pigment-grade TiO₂ test particles (d₅₀ = 173 nm by number) by daily oral gavage at a dose of 24,000 mg/kg bw/day. There were no adverse effects measured during or following the end of the exposure period; and the NOAEL was determined to be 24,000 mg/kg bw/day; 3) In an acute oral toxicity study (OECD TG 425), female rats were administered a single oral exposure of surface-treated rutile/anatase nanoscale TiO₂ particles (d₅₀ = 73 nm by number) with doses up to 5000 mg/kg and evaluated over a 14-day post-exposure period. Under the conditions of this study, the oral LD₅₀ for the test substance was >5000 mg/kg bw. In summary, the results from these three toxicity studies – each with different TiO₂ particulate-types, demonstrated an absence of adverse toxicological effects. Apart from reporting the findings of these three studies, this publication also focuses on additional critical issues associated with particle and nanotoxicology studies. First, describing the detailed methodology requirements and rigor upon which the standardized OECD 408 guideline subchronic oral toxicity studies are conducted. Moreover, an attempt is made to reconcile the complex issue of particle size distribution as it relates to measurements of nanoscale and pigment-grade TiO₂ particles. Clearly this has been a confusing issue and often misrepresented in the media and the scientific literature. It is clear that the particle-size distribution for pigment-grade TiO₂, contains a small (“tail”) component of nanoscale particles (i.e., 21% by particle number and <1% by weight in the test material used in the 90-day study). However, this robust particle characterization finding should not be confused with mislabeling the test materials as exclusively in the nanoscale range. Moreover, based upon the findings presented herein, there appears to be no significant oral toxicity impact contributed by the nanoscale component of the TiO₂ Test Material sample in the 90-day study. Finally, it seems reasonable to conclude that the study findings should be considered for read-across purposes to food-grade TiO₂ particles (e.g., E171), as the physicochemical characteristics are quite similar.     

重组成骨蛋白-1在钛合金微粒环境下对MC3T3-E1成骨细胞增殖、分化、矿化的影响

目的在钛-6铝-4钒(Ti-6Al-4V)合金微粒环境下观察重组成骨蛋白-1(recombinant OP-1,r OP-1)对成骨细胞的影响,为防治关节假体无菌性松动提供新的治疗途径。方法根据小鼠颅顶骨前成骨细胞亚克隆14(MC3T3-E1)中是否加入Ti-6Al-4V微粒和r OP-1,分为微粒组(5、10、15μg/m L Ti-6Al-4V)、处理组(微粒组加入200 ng/m L r OP-1)、阳性组(加入200ng/m L r OP-1)和对照组,检测各组24、72、120 h MC3T3-E1细胞增殖能力、72 h碱性磷酸酶(akaline phosphatase,AKP)、骨钙素(osteocalcin,OCN)和骨桥蛋白(osteopontin,OPN)mRNA的表达,及120 h成骨细胞的矿化能力。结果 1r OP-1无促进Ti-6Al-4V微粒环境下成骨细胞增殖能力,与微粒组比较,差异无统计学意义(P>0.05);2r OP-1可提高成骨细胞分化,与对照组比较差异有统计学意义(P<0.05);同时逆转Ti-6Al-4V微粒抑制成骨细胞分化,与微粒组比较差异有统计学意义(P<0.05);3茜素红S染色后Ti-6Al-4V微粒钙结节数量随着浓度增加逐渐降低,和微粒组比较,加入r OP-1后钙结节数量呈增多趋势。结论 Ti-6Al-4V微粒环境下,r OP-1无提高成骨细胞增殖能力,能提高细胞分化矿化能力,r OP-1可以作为潜在治疗关节假体无菌性松动一种方法。     

钛板内固定治疗跟骨骨折的临床疗效观察

目的：探讨钛板内固定治疗跟骨骨折的临床应用效果。方法选择2013年6月-2014年4月医院跟骨骨折患者120例,随机分为试验组与对照组各60例。所有患者予常规治疗及护理。试验组采用切开复位钛板内固定法治疗;对照组采用 Westbue 法治疗。比较2组临床疗效。结果试验组优良率为91.6%明显高于对照组的70.0%,差异有统计学意义（P ﹤0.05）。试验组术后并发症发生率明显低于对照组。结论钛板内固定治疗跟骨骨折临床疗效优于传统保守治疗,明显改善患者预后状况及功能恢复情况,值得临床推广应用。     

Biodegradation of Titanium Implants After Long-Time Insertion Used for the Treatment of Fractured Upper and Lower Jaws Through Osteosynthesis: Element Analysis by Electron Microscopy and EDX or EELS

Twelve patients underwent an osteosynthesis with titanium to treat upper and lower jaw fractures. Six to 12 months later, the miniplates were removed. Tissue samples were analyzed by light and electron microscopy for detection of a metallosis. The analysis showed new bone formation like callus tissue around the miniplates. In some cases small, rounded deposits and accumulation of colloid-like particles located next to bigger titanium artifacts were detected in the cytoplasm of histiocytes and in the matrix of connective tissue. The titanium was identified by elemental analysis using EDX in SEM as well as by EELS and electron diffraction in TEM. Both kinds of particles contain titanium, but they seem to be different in composition and derivation. The bigger particles seem to consist of metallic titanium and sourced by working on the metallic implants during the implantation itself. On the other hand, the colloidal-like, small, rounded particles in tissue macrophages and outside the cells in the matrix of connective tissue are presumably of other origin; for example, they could be derived from biodegradation and chemical conversion of the metallic implants. The titanium miniplates were examined before and after implantation by using ESCA technique and revealed metallic titanium and different compositions with other elements. The amount of titanium load of the tissue was very low in most cases and presumably not of biomedical relevance.     

Repairing Defect and Preventing Collapse of Canine Femoral Head Using Titanium Implant Enhanced by Autogenous Bone Graft and rhBMP-2

There is a direct relationship between mechanical stress and the progressive collapse of the necrotic region in osteonecrosis of the femoral head. The titanium implant combined with autogenous bone graft and recombinant human bone morphogenetic protein (rhBMP)-2 to repair the defect and prevent collapse of the femoral head was investigated. The femoral head defects were made by the trapdoor procedure and then the defects were filled, respectively, with the titanium implant combined with autogenous bone graft and rhBMP-2, with autogenous bone graft and rhBMP-2, and with autogenous bone graft alone. Roentgenographic and histological examinations were performed at various times postoperatively. The defects were repaired completely and the titanium implant was integrated with the surrounding bone tissues. The defects healed faster than did without rhBMP-2. No trapdoor cartilage collapsed and joint space narrowed. The titanium implant combined with autogenous bone graft and rhBMP-2 can enhance the repairing procedure and prevent the collapse of the femoral head.     

钛夹标记联合CT图像后处理技术在早期胃癌腹腔镜术前定位中的应用

目的探讨钛夹标记联合CT图像后处理技术在早期胃癌腹腔镜术前定位中的应用。方法30例早期胃癌患者经消化道内窥镜检查发现病灶并常规活检后,于瘤体旁放置钛夹,术前12~24 h分别行腹部卧位X线摄影及腹部CT平扫,通过CT图像后处理技术及腹部X线摄影来了解钛夹的位置,以便术前确定病灶部位及范围,并与术中所见病灶位置进行比较,评判两种方法对早期胃癌腹腔镜手术的术前定位准确率,并通过CT对胃周围淋巴结转移进行初步评判。结果本组30例患者术前行钛夹标记联合CT图像后处理技术对胃癌的定位与手术结果符合率为100%(30/30),其定位准确率优于钛夹标记联合腹部X线摄影对胃癌的定位方法。所有患者均顺利完成腹腔镜手术。结论对于早期胃癌患者,利用钛夹标记联合CT图像后处理技术是术前准确可靠的病灶定位方法,亦可大体了解胃周围淋巴结的情况,对早期胃癌腹腔镜手术顺利完成有重要的临床意义。     

Effect of coating thickness and its material on the stress distribution for dental implants

Dental implants have been increasingly used to recover the masticatory function of lost teeth. It has been well known that the success of a dental implant is heavily dependent on initial stability and long-term osseointegration due to optimal stress distribution in the surrounding bones by the concept implant surface coating. Hydroxyapatite (HAP), as a coating material, has been widely used in dentistry due to its biocompatibility. Some investigations show a benefit of coating dental implants with HAP, and others concluded that HAP coating reduces the long-term implant survival. Therefore, the aim of this investigation is to design a new functionally graded dental implant coating, as well as studying the effect of coating thickness on the maximum von Mises stresses in bone adjacent to the coating layer. The gradation of the elastic modulus is changed along the longitudinal direction. Stress analysis using a finite element method showed that using a coating thickness of 150 µm, functionally graded from titanium at the apex to the collagen at the root, will successfully reduce the maximum von Mises stress in bone by 19% and 17% compared to collagen and HAP coating respectively.