Pullout strength of anterior spinal instrumentation: a product comparison of seven screws in calf vertebral bodies

A lot of new implant devices for spine surgery are coming onto the market, in which vertebral screws play a fundamental role. The new screws developed for surgery of spine deformities have to be compared to established systems. A biomechanical in vitro study was designed to assess the bone–screw interface fixation strength of seven different screws used for correction of scoliosis in spine surgery. The objectives of the current study were twofold: (1) to evaluate the initial strength at the bone–screw interface of newly developed vertebral screws (Universal Spine System II) compared to established systems (product comparison) and (2) to evaluate the influence of screw design, screw diameter, screw length and bone mineral density on pullout strength. Fifty-six calf vertebral bodies were instrumented with seven different screws (USS II anterior 8.0 mm, USS II posterior 6.2 mm, KASS 6.25 mm, USS II anterior 6.2 mm, USS II posterior 5.2 mm, USS 6.0 mm, USS 5.0 mm). Bone mineral density (BMD) was determined by quantitative computed tomography (QCT). Failure in axial pullout was tested using a displacement-controlled universal test machine. USS II anterior 8.0 mm showed higher pullout strength than all other screws. The difference constituted a tendency (P = 0.108) when compared to USS II posterior 6.2 mm (+19%) and was significant in comparison to the other screws (+30 to +55%, P < 0.002). USS II posterior 6.2 mm showed significantly higher pullout strength than USS 5.0 mm (+30%, P = 0.014). The other screws did not differ significantly in pullout strength. Pullout strength correlated significantly with BMD (P = 0.0015) and vertebral body width/screw length (P < 0.001). The newly developed screws for spine surgery (USS II) show higher pullout strength when compared to established systems. Screw design had no significant influence on pullout force in vertebral body screws, but outer diameter of the screw, screw length and BMD are good predictors of pullout resistance.     

数字化导航模板辅助全膝关节置换的模拟研究

 目的 探讨数字化导航模板辅助全膝关节置换的准确性和可行性。方法 取成年尸体下肢标本 20具,随机分为导航模板组和传统方法组,每组 10具 20个膝关节。导航模板组术前行下肢全长 CT扫描,利用逆向工程软件对 CT数据进行处理,设计与股骨远端和胫骨近端匹配的可定位截骨平面和外旋轴的导航模板,通过快速成型机制作模板实物用于尸体标本的全膝关节置换手术操作。传统方法组按常规全膝关节置换手术操作。术后通过 CT扫描比较两种方法定位的截骨准确性。结果 导航模板与股骨髁和胫骨平台贴合紧密,无明显移动。导航模板组 18个膝关节的股骨远端和胫骨近端截骨面与下肢机械轴垂直,2个膝关节内翻; 17个膝关节后髁截骨面与通髁轴完全平行,3个膝关节有成角。传统方法组 20个膝关节均出现下肢机械轴内外翻,其中 5个膝关节大于 5°; 20个膝关节均出现后髁截骨面与通髁轴成角,其中 10个膝关节大于 3°。结论 导航模板法的股骨远端、胫骨近端和股骨外旋截骨准确性均高于传统手术方法。     

个性化选择在义齿美容修复的临床应用

目的：研究患者的个性化在义齿修复过程中对美容的影响。方法：临床上有针对性地选择数个患者,通过在整体设计、材料选择、颜色匹配、面容改善等几个方面个性化地进行临床修复,并对治疗前后通过摄影比较。结果：患者治疗前后美容上有极大的改善,对治疗结果很满意。结论：个性化选择对患者的义齿美容修复具有重要的意义。     

Opinions on research and evidence based medicine within the UK osteopathic profession: A thematic analysis of public documents 2003–2009

Background

Very little is known about the attitudes of osteopaths in the UK towards research and evidence based medicine (EBM). It is important to understand the attitudes of osteopaths in order to identify the issues surrounding research and EBM in osteopathy.

Objective

The objective of this study was to collect and thematically analyse public documents (for example editorials, letters, forum threads and essays) from carefully chosen sources, published 2003–2009. Such analysis enables themes and concepts to be drawn out of the data to reflect the hopes, goals, concerns or perceived barriers that osteopaths may have with regards to research and EBM.

Data sources

Two UK osteopathic magazines, two websites for osteopaths and five health databases were searched for data sections. Data sections were selected according to inclusion and exclusion criteria. Magazines were read by the researcher, the two websites’ forum archives were searched using keywords ‘research’ and ‘evidence based medicine,’ and the five databases were searched using MeSH terms ‘osteopathic medicine,’ ‘research’ and ‘evidence based medicine.’

Method

The method was a 6 stage thematic analysis of public documents 2003–2009. Data sections were identified from the public documents using inclusion and exclusion criteria. Sections were broken down into codes and themes were derived from codes using a flexible and reflective process. Higher concepts were then derived from the themes according to relationships and similarities identified between themes.

Results

129 data sections were identified from the 5 sources and coded. 20 themes were derived from the codes, then the themes were further analysed and six concepts were derived from the themes. A final conceptual framework was constructed to represent osteopaths’ opinions on research and EBM. The concepts identified were “uniqueness,” relating to respect for osteopathic principles and Andrew Taylor Still, and the profession maintaining autonomy from mainstream medicine; “position in healthcare,” relating to identifying the need to integrate into mainstream healthcare and gain status and respect from physicians outside of the osteopathic profession; “necessity,” relating to reasons why research should be carried out, and what it should focus on; “barriers,” relating to issues that hinder osteopaths in research such as experience, methods, funding; “solutions,” relating to some suggestions made for overcoming barriers; and “negative impact,” relating to the possible negative consequences that research might have on the profession.

Conclusions

A broad and complex range of issues were identified and osteopaths appear to have differing views about the importance of research and their position in a wider healthcare structure. Preserving osteopathic principles and the profession’s uniqueness is important when considering research and EBM. A fear exists with regards to the impact that research might have on clinical practice. Recommendations for further osteopathic research have been made.     

肱骨近端Ⅱ-Ⅲ级骨巨细胞瘤保肢手术与康复训练7例

目的：探讨瘤段扩大切除加人工假体置换术及围手术期的康复治疗对肱骨近端骨巨细胞瘤的保肢、关节功能恢复的效果。方法：自2007年3月到2010年3月,共收治肱骨近端Ⅱ-Ⅲ级骨巨细胞瘤7例,男3例,女4例,平均年龄34.6岁（18～49岁）,平均病程19个月（6～35个月）。7例术前均经病理检查及X线证实为肱骨近端骨巨细胞瘤。临床表现为进行加重的肩部疼痛,体检臂近端肿胀、压痛明显,肩关节活动障碍。所有病例采用瘤段扩大切除后以定制的人工假体置换,围手术期辅以康复训练。采用CMS评分及OSIS评分评价患肩功能与患肩稳定性。结果：7例均获随访,时间14～35个月,平均17个月。术后随访无重大并发症发生,无复发病例。术后1年7例患肩CMS评分平均为70.7分（63～82分）,OSIS评分平均25.1分（18～29分）。肩关节功能优2例,良5例;肩关节稳定性优1例,良6例。结论：瘤段扩大切除加人工假体置换术辅以围手术期功能训练治疗肱骨近端Ⅱ-Ⅲ级骨巨细胞瘤疗效确切,达到切除肿瘤与保肢目的。     

颅面外科三维诊断分析和手术设计系统的临床应用研究

目的 探讨复杂颅面畸形计算机辅助诊断及整复手术设计的临床应用价值。方法 建立了颅颌面外科三维诊断分析和手术设计计算机系统（3-DCMFCADS）,并将其用45例颅面畸形的定量诊断和整复手术设计,结果 与头颅骨骼直接测量相比较,三维CT影像测量结果误差微小,各项测量指标的平均误差均小于5%。精密度最大变异系数仅1.92%,借助本系统实现了镜像法手术模拟设计和移植体或置入修复体三维模型构建,对手术实施具有指导作用。结论 3-DCMF-CAD系统的临床应用,为颅面畸形整复外科手术治疗提供了技术方法和具体指导。     

A randomized, prospective study of primary total knee components designed for increased flexion

This prospective, randomized study reports early results for range of motion (ROM) after primary total knee arthroplasty. Group A received standard posterior-stabilized (PS) implants. Group B had PS implants designed for increased flexion. Average preoperative ROM was 2 degrees to 121 degrees for group A and 1.8 degrees to 122 degrees for group B. At 12-month follow-up, average ROM for group A was 0.6 degrees to 120 degrees as compared with 0.6 degrees to 133 degrees for group B (P < .05). Significantly more patients in group B flexed more than 135 degrees (P < .05). Furthermore, 12 patients (48%) in group A failed to return to preoperative ROM versus 2 patients (8%) in group B (P < .05). Although long-term follow-up is desirable, these early results support the use of PS implants designed for increased flexion.     

Controller design for optimal tracking response in discrete‐time systems

The problem of designing a controller, which results in a closed‐loop system response with optimal time‐domain characteristics, is considered. In the approach presented in this paper, the controller order is fixed (higher than pole‐placement order) and we seek a controller that results in closed‐loop poles at certain desired and pre‐specified locations; while at the same time the output tracks the reference input in an optimal way. The optimality is measured by requiring certain norms on the error sequence—between the reference and output signals—to be minimum. Several norms are used. First, l₂‐norm is used and the optimal solution is computed in one step of calculations. Second, l_∞‐norm (i.e. minimal overshot) is considered and the solution is obtained by solving a constrained affine minimax optimization problem. Third, the l₁‐norm (which corresponds to the integral absolute error‐(IAE)‐criterion) is used and linear programming techniques are utilized to solve the problem. The important case of finite settling time (i.e. deadbeat response) is studied as a special case. Examples that illustrate the different design algorithms and demonstrate their feasibility are presented. Copyright © 2007 John Wiley & Sons, Ltd.     

根据口鼻轮廓设计单侧唇裂Ⅱ期修复手术

目的 探讨根据口鼻轮廓线设计单侧唇裂Ⅱ期修复手术的方法及临床效果.方法 通过对鼻唇弯曲轮廓的细微研究,从解剖、力学分析入手,结合唇裂畸形的特点,逐步形成以口鼻弯曲轮廓线为手术切口的术式,参考水平线和正中垂直线及外形,对单侧唇裂患者进行Ⅱ期综合整体修复术.结果 该手术方法应用于临床效果医患双方满意.结论 根据口鼻轮廓线设计单侧唇裂Ⅱ期修复术,能取得良好的畸形修复和外形美观效果.     

数字化微笑设计在前牙瓷贴面美学修复中的应用及其修复效果分析

目的：分析结合数字化微笑设计（DSD）进行前牙瓷贴面修复患者的术后满意度及修复体的修复效果,探讨其在前牙美学修复中的应用。方法：选择因四环素牙、氟斑牙、牙体着色、轻度釉质缺损和前牙散在间隙等原因要求进行美学修复,且临床诊断符合贴面修复适应证的患者32例共91颗前牙。术前采用DSD软件对患者进行牙齿形态的美学分析及虚拟修复效果的预览,并在设计结果指导下进行牙体预备,常规印模制取后制作IPS e-max瓷贴面,最后完成永久修复体的戴入。在治疗完成后采用调查问卷的形式让患者对修复体的外形、与邻牙协调程度、颜色、发音、微笑效果和医患交流等6项内容作出满意度评价,并在治疗后1、3、6和12个月参照改良版美国公共卫生署（USPHS）标准对瓷贴面的临床修复效果进行评估。结果：患者对于各项调查内容的满意率均可达90%以上,其中对于微笑效果和医患交流2项满意率高达100%。将DSD应用于瓷贴面修复后,患者对于最终修复体的功能、美学效果和医患交流体验等各方面满意度较高。各时期修复体临床表现,修复后1个月,4颗牙齿出现轻度牙龈炎,3颗牙齿出现术后敏感;修复后3个月,1颗修复体出现不影响美观及功能的微小缺损,3颗牙齿出现牙龈轻度红肿,1颗修复体轻微变色;修复后6个月,1颗修复体出现切缘缺损,4颗牙齿出现轻度牙龈炎;修复后12个月,2颗牙齿出现修复体缺损,3颗牙齿修复体边缘欠密合,1颗牙齿出现牙龈炎。修复后出现牙龈炎症反应的患者在经过正确的口腔卫生指导后牙周状况均有明显好转,且上述缺损均不影响修复体的美观和功能,调磨后可正常使用,医患双方对修复体的修复效果均满意。结论：将DSD与瓷贴面修复联合应用是一种可获得较高患者满意度和理想修复效果的前牙美学修复方案。