坚硬接骨板固定后局部骨质疏松的骨组织形成计量学的实验研究

本实验通过骨组织形态计量学的方法，对家兔完整胫骨坚硬接骨板内固定后局部骨组织的变化进行了研究，实验家兔随机分为１、２、３、４组和空白对照组，固定时间为６．８．１０和１２周。对不脱钙骨组织切片在纵切面和横切面上进行普通光和莹光分析测量。结果发现：坚硬接骨板内固定后六周时固定段骨即出现骨质疏松，发生在哈佛氏系统的骨丢失，１０周后胄内膜表面出现骨吸收，、骨髓腔增大，两上表面的骨重建单位的负稀使固定段皮质     

接骨板内固定和局部骨质疏松

坚硬接骨板加压内固定可使骨折发生一期愈合,并有利于肢体早期功能活动。然而,接骨板内固定也可诱发骨局部血供紊乱和应力刺激下降,从而导致固定骨段,特别是板下骨的骨质疏松。它是固定骨段发生再骨折的潜在原因。早期的暂时性骨丧失可能与血供紊乱有关,而持久存在的骨质疏松则主要因应力遮挡作用所致。接骨板刚度越高,应力遮挡作用越大,因而局部骨质疏松也就越严重。取出接骨板后,局部骨质疏松可以完全逆转,但需二次手术。因此,减少血供紊乱,避免长期的应力遮挡作用是目前需要解决的课题。     

骨组织形态计量学和微CT测量技术在骨质疏松研究中的应用

骨质疏松以进行性骨量减少、骨组织微结构退化为主要病理特征。骨质疏松程度评估或诊断方法中骨密度测量方法不能反映骨微结构变化,存在难以完整体现骨生物学特性的缺陷;骨组织形态计量学通过对骨标本动态、静态学参数测量,可从定性和定量角度较全面描述骨量、骨微结构变化状况,但在获取标本时具有创伤性且技术繁琐;基于骨组织形态计量学发展而来的微CT(μCT)扫描与测量技术,尽管难以获取并反映骨组织局部的细胞形态和骨形成率、吸收率等变化参数,但可精确显示骨组织三维结构特征,所测得的参数误差小,且操作简便,定位准确。在骨质疏松研究领域,骨组织形态计量学和μCT技术常用于动物实验或特殊患者的诊断,尤其是用于骨质疏松药物疗效的评价。     

老年与青年股骨头内松质骨组织形态计量学比较研究

目的 研究老年部骨折患股骨头松质骨结构。方法 取股骨示本４９只,分成老年组２６例及青年组２３例。在股骨头致密区（负重区）和疏松区（非负重区）各截取软骨下３ｍｍ处７ｍｍ×５ｍｍ×５ｍｍ松质骨各一块作骨组织形态计量测定。结果 老年组致密区和稀疏区骨组织形态参数松质骨体积（ＴＢＶ）、平均骨小梁密度（ＭＴＰＤ）、平均骨小梁厚度（ＭＴＰＴ）、骨小梁间连接点数（Ｔｂ、ｎ）均明显低于青年组（Ｐ〈０．０５～０．     

波形与直形接骨板内固定对局部皮质骨微循环影响的形态学研究

本研究旨在观察和比较波形与直形钢板内固定对局部皮质骨血供的影响。采用微血管墨汁灌注技术观察了两种钢板固定于完整兔股骨干后不同时期皮质骨内微循环的形态改变。直形钢板固定后板下及板对侧皮质骨微循环出现早期血管减少,以后反应性增生;波形钢板固定后板下早期未见明显血管减少,后期亦反应性增生,但不如直形钢板固定侧剧烈。结论:波形钢板内固定对骨内微循环的影响明显弱于直形钢板,其引起骨质疏松的状况亦低于直形钢板。     

拱形交叉固定接骨板的生物力学研究

目的　报告拱形交叉固定接骨板与另外两种接骨板生物力学试验结果。方法　对同种材质拱形板、矩形板 ,应力型板进行四点弯曲电测量 ,三点弯曲、循环拔钉及扭转拔钉和冲击对比试验。结果　电测试验 ,拱形板中央应力值最小 ,抗弯强度最大 ;三点弯曲试验 ,拱形板强度极限最大 ;循环拔钉试验 ,拱形板开始拔钉循环次数最多 ;扭转拔钉试验 ,拱形板拔钉时 ,扭矩、扭转角最大 ;冲击试验 ,拱形板冲击韧性最高。结论　拱形板抗弯、抗扭强度及防拨钉和抗冲击能力最高 ,克服弯板、断板、拔钉能力强     

加强骨质疏松骨折内固定的研究现状

骨质疏松骨折内固定的早期稳定性可通过改进内固定物的设计和材料，完善手术操作以及加强骨基质是以提高。     

Less rigid internal fixation plates: Historical perspectives and new concepts

In the application of “rigid” plates for diaphyseal fractures, lack of callus healing and overprotection of the underlying bone are viewed by many investigators as undesirable consequences. Potential solutions offered to overcome these deficiencies include modification of the timing of plate removal, use of biologically degradable materials for plates so that stressshielding can be minimized, and use of less rigid plate fixation systems. This study emphasizes the selection of appropriate design criteria for less rigid plate-fixation systems. To accomplish this goal, the axial, bending, and torsional stiffness parameters are considered in place of the oversimplified terms such as “flexible plate” or “elastic fixation.” With the aid of finite element modeling and simplified bench experiments, we performed parametric studies and singled out the plate axial stiffness as the dominant factor in altering the bone stresses. As a result, we designed two experimental plates, one a thin Ti-6Al-4V (titanium with 6% aluminum and 4% vanadium) alloy plate with low stiffness in axial and bending directions, and the other a tubular stainless steel plate with low stiffness in the axial direction but moderate stiffness in bending and torsional directions. The low-stiffness Ti-6Al-4V alloy plate was first tested in a demanding bilateral canine midshalt osteotomy, and proved to be inadequate. Both experimental plates were successful in the unilateral osteotomies, with the tubular plate yielding the best results. After 6 months of plating, the bones beneath the tubular plate had superior mechanical and structural properties as compared to those of the control “rigid” stainless steel and the Ti-6Al-4V alloy plates. Application of this plate prolonged for 9 months did not cause reduction in bone properties and strength. The success of the tubular plate is due to its moderate bending and torsional stiffnesses, which provide adequate fixation to achieve callus union, while its low axial stiffness permits the underlying bone to share the physiological stresses needed for bone remodeling. These drastic changes in mechanical demands on the internal fixation plate during the early healing phase and the postunion remodeling phase are discussed.     

The mechanical and morphological properties of bone beneath internal fixation plates of differing rigidity

The internal fixation of diaphyseal fractures by bone plates is a well recognized treatment. The normal physiological stress of bone is reduced by plates that cause a negative balance of bone-remodeling processes. Many investigators have shown that the degree of stress protection is dependent on the rigidity of the plates. It was the aim of this study to quantify mechanical and morphological changes at different locations in a plated diaphyseal bone as a function of differing plate rigidity. Two types of plates with the same size but different materials were used. The stainless steel plates had a modulus of elasticity and bending stiffness 3.2 times higher than the carbon fiber reinforced carbon plates. Both types of plates were applied to the intact right and left femora of six foxhounds for 6 months. The stiffer stainless steel plates led to a significantly higher bone loss and correspondingly greater loss of mechanical properties. These effects were greatest directly beneath the plate and less with increasing distance from the plate.     

Experimental studies on the use of a cushioned plate for internal fixation

Summary Internal fixation is widely used in the operative treatment of fractures, but various problems, such as local osteoporosis, may occur when living bone is fixed with a rigid metal plate. We propose a new method of immobilisation, which we have termed cushioned plate fixation, in an attempt to solve some of these problems.Cushioned plate fixation involves a silicone rubber cushion placed between the steel plate and the bone. On the basis of data obtained from animal experiments in vivo and mechanical tests in vitro, we conclude that the cushion is effective in preventing osteoporosis without decreasing the strength of fracture fixation. We believe that this method might improve the mechanical biocompatibility of plate fixation.

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Résumé L'ostéosynthèse par plaque est d'usage courant dans le traitement opératoire des fractures. Cependant différents problèmes se posent lorsqu'un os vivant est fixé par une plaque métallique rigide. Nous avons imaginé une nouvelle méthode de fixation interne appelée «Fixation par plaque à coussin» qui nous a permis de résoudre plusieurs de ces problèmes.Cette technique consiste à mettre un coussin entre la plaque de compression auto-dynamique (K. U. Compression plate) et l'os. Comme coussin, nous avons employé de la gomme de silicone à surface irrégulière.Les résultats des expérimentations animales et mécaniques ont montré que la mise en place du coussin entre la plaque de compression auto-dynamique et l'os empêche l'apparition de l'ostéoporose sans diminuer la force de fixation de la fracture. Nous pensons que cette nouvelle méthode améliore la biocompatibilité mécanique de la plaque.

     

The anatomical study of transoral atlantoaxial reduction plate internal fixation

Irreducibleanterioratlantoaxialdislocationwithventralspinalcordcompressionpresentsadifficultsurgicalchallenge.Nowasagenerallyacceptedoptionforthiscondition,decompressionthroughtransoralapproachhastobefollowedby anotheroperationwithinstrumentationandfusionofthe uppercervicalspinetoachievesegmentalstability.HarmsandKandziora1havedescribeddirectinternal platefixationsthroughtransoralapproach,buttheplate adoptedbyHarmsdidnothavealockingmechanism andtheplateusedbyKandziorafailedtoachieve immediate…     

骨水泥材料在增强股骨转子间骨折内固定中的应用进展

如何对股骨转子间骨折、尤其是头颈骨块进行有效固定,进而稳定并支撑骨质疏松的骨折端,已成为当今创伤骨科研究的热点之一。为了减少固定失败率,临床上除了提高内固定的设计,应用骨增强材料提高固定的效果是另一个富有前景的研究领域。因此,本文围绕骨水泥增强材料的研究历史、材料特点、目前其生物力学和临床应用研究等方面进行综述,以提高对骨生物增强材料进行内固定的原理、手术技术和应用范围的认识,进而为其临床应用的选择提供帮助。     

带螺纹内固定贯穿股骨头骺板实验研究

目的 :通过带螺纹内固定贯穿股骨头骺板的实验研究,分析带螺纹内固定是否会造成生长抑制及其关系。方法:新西兰兔40只,分为4组,每组10只,螺纹针穿透骺板并留置其内造成骺板损伤,通过螺纹针数量增减改变损伤面积,A组为空白对照组,B组为损伤骺板面积的4%,C组为损伤骺板面积的6%,D组为损伤骺板面积的8%。用X线机对4组实验对象进行定期摄片观察,术后2周拆内固定,继续定期摄片,判断骺板有无早闭等并发症。结果 :各实验组与对照组在实验观察期间,股骨颈长度、直径,股骨头直径、骺板闭合时间差异均无统计学意义。股骨颈长度、直径,股骨头直径生长速度先快后慢,在骺板将要闭合时最慢。结论:兔股骨头骺板损伤面积在8%以下是安全的,不会对股骨颈发育起到抑制作用。螺纹针可以用于兔骺板部位,未发现该固定方法对骺板的发育起到抑制作用。     

The bagby compression bone plate

Summary A compression bone plate was designed in 1956 by modifying a Collision plate. The advantage in fracture healing is seen as improved fixation rather than any effect on osteogenesis due to the compression.

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Résumé Une plaque permettant la compression a été mise au point par l'auteur en 1956, par modification d'une plaque précédente. L'amélioration de la consolidation osseuse tient à la meilleure fixation qu'assure ce matériel plutôt qu'à un effet direct de la compression sur l'ostéogénèse.

     

吻合血管的骨移植及钛板内固定修复下颌骨缺损

目的 探讨吻合血管的游离髂骨或腓骨移植及钛板坚强内固定在修复下颌骨缺损中的临床应用效果。方法 选择7例以旋髂深动静脉为蒂的游离髂骨肌瓣和2例以腓动静脉为蒂的游离腓骨肌瓣修复9例下颌骨缺损，并用钛板坚强内固定，血管的动静脉蒂分别与颌外动静脉吻合。结果 9例术后2～4周经放射性核素锝亚甲基二磷酸盐(^99mTc MDP)扫描证实血供良好，移植骨成活。经6个月至3年随访，移植骨固位稳定。结论 吻合血管的骨移植及钛板内固定是修复下颌骨缺损的最佳选择之一。     

A biomechanical assessment of plate fixation, with insufficient bony support

The use of an internal fixation plate in the presence of a bone defect was studied using a theoretical model of an idealized long bone having a circular cross section and loaded using a combination of axial and bending loads. The analysis showed that the "bending-open" loading mode does not occur if, in the normal unplated bone, the line of action of the resultant axial load passes within the outer cortex at the location where the plate is to be applied. In this situation the fracture will deform in a "bending-closed" mode regardless of whether the plate is attached to the tension or the compression side. If bony contact cannot be achieved, lower plate stress is always encountered when the plate is attached to the compression side instead of the tension side. In vivo verification of the model was addressed in a pilot experiment using instrumented metal plates applied bilaterally to the femora of one dog. Bilateral bone defects were created in the midfemoral canine diaphysis. On one leg the plate was applied to the lateral aspect ("tension" side), and on the other leg the plate was applied to the medial aspect ("compression" side). The plate attached to the lateral aspect deformed plastically in the bending-closed mode. The contralateral plate that was attached to the medial aspect (compression side) of the femur did not show signs of plastic deformation. Furthermore, the plate strains were lower in the plate attached to the medial aspect than those in the plate attached to the lateral aspect.(ABSTRACT TRUNCATED AT 250 WORDS)     

后路短缩截骨内固定治疗骨质疏松性症状性陈旧胸腰椎骨折

目的:观察后路短缩截骨内固定治疗骨质疏松性症状性陈旧胸腰椎骨折的疗效。方法:回顾18例后路短缩截骨内固定治疗的陈旧性骨质疏松性胸腰椎骨折患者的临床和影像学资料,平均年龄67岁。T12、L1、L2节段分别为8例、5例、5例,其中骨折不愈合4例,后凸畸形并神经功能障碍11例,爆裂骨折合并神经压迫保守治疗无效3例。应用疼痛视觉模拟(VAS)评分及JOA评分法评估临床结果,Frankel分级评价神经功能状态,X线评估融合及后凸状况,并观察手术并发症。结果:平均手术时间213min,平均出血量780ml。随访27个月(19～48个月),末次随访时VAS评分由术前8.9分减少到2.5分,JOA评分(25.1±4.1分)显著优于术前(12.7±3.6分,P<0.001);Frankel分级5例由术前C级恢复到D或E级,9例由D级恢复到E级;平均后凸角由术前37.3°矫正到术后6.5°,末次随访时为13.7°。无内固定相关并发症。结论:后路短缩截骨内固定是治疗骨质疏松性症状性陈旧胸腰椎骨折的有效方法,但应严格手术指征。