【作者】 艾建国；

【导师】 初同伟；

【作者基本信息】 第三军医大学 ， 外科学， 2010， 硕士

【摘要】 研究背景和目的：脊柱前路内固定是针对脊柱肿瘤、结核、椎体骨折以及椎间盘病变等各种脊柱疾病的有效内固定方式，在各种脊柱前路内固定器械中，由法国SCIENT’X公司设计制造的腰骶椎前路安全钢板(PACH)是近年来在脊柱外科领域应用的较多的内固定器械之一，适用于腰椎前路融合后的前方或侧前方固定，具有以下特点：1、其形状符合椎体前侧的水平曲度，有助于提高水平与矢状面的稳定性；2、双侧固定提供立体三维稳定性；3、拥有螺钉安全系统：焊接在钢板上的弹性钛条可弯曲以使螺钉通过后复原以避免螺钉退出；4、表面刻痕可使其完美贴附于椎体。但我们在临床应用中也逐渐发现该钢板存在一些不足：1、该钢板为单体双孔钢板，手术一般需植入2块钢板过程复杂，若只植入1块钢板固定的牢固性可能不足；2、该钢板是依据国外人种脊柱解剖特点设计，不能完全符合国人脊柱解剖特点；3、术中2块钢板放置的间距及角度无明确标准，生物力学稳定性无法保证。本研究的目的在于通过对国人腰骶椎解剖结构的统计分析，在现有PACH内固定钢板的基础上，将其改进为整体复合四孔钢板，并使其弧度、长度及角度能完全适应国人腰骶椎解剖结构，并在脊柱标本上进行生物力学测试，各项生物力学指标达到预期结果。研究方法：1、通过对约350例正常成人腰骶椎侧位X线片腰骶角、腰5骶1椎体及椎间盘高度的测量并进行统计分析，得出正常国人腰骶椎结构的数值范围。2、在对国人腰骶椎结构测量结果的基础上，结合腰5骶1节段脊柱前侧血管分布特点，设计出改进型腰骶椎前路钢板高度、宽度、角度、弧度等各项参数，使其符合国人腰骶椎解剖特点。3、生产钢板样品，并在人体脊柱标本上进行生物力学测试，比较改进型钢板组、PACH钢板组、对照组的生物力学特点。研究结果：1、通过对350例正常成人站立位腰骶椎正位侧位X线片腰骶角、腰5及骶1椎体、椎间盘高度的测量，得出正常国人腰骶椎结构的数值统计结果：腰5椎体高度(27.1±2.3)mm，骶1椎体高度(22.3±2.8)mm，腰5骶1椎间盘高度(8.2±0.3)mm，腰骶角(129°±5.9°)。2、依据对国人腰骶椎部位解剖结构的研究结果，我们制定了改进型腰骶椎前路钢板内固定系统的设计参数，钢板高度：28、32 mm 2种，钢板宽度：20 mm，钢板角度：125°、130°、135°3种，钢板弧度：弧长22 mm，弦长20 mm，螺钉长度：30、32.5、35、37.5、40、42.5、45mm，螺钉直径：5 mm。球形头全螺纹自攻螺钉,螺钉自然状态下偏向头尾两侧，与头尾侧之间夹角18°。3、试验试件先进行弯曲测试，持续加载至设定桡度，记录载荷-位移曲线，选取500N载荷下测定对照组和试验组在后伸、侧屈条件下位移变化比较，结果显示改进型钢板组抗弯能力优于PACH组(P<0.05 )。再进行压缩实验，根据载荷-位移曲线，计算出各组在载荷400N下刚度值，PACH组为87.4N/mm，改进型钢板组为105.8N/mm，两者相差21％，有统计学差异(P<0.05)。最后进行扭转实验，当达到5°的转角时，改进型钢板组和PACH组的脊柱试件所需的扭矩较对照组分别增加54.6%和53.7%，且两者扭转刚度相似，没有统计学差异(P＞0.05)。研究结论：1、本研究针对国人腰骶椎部位包括腰骶角、L5及S1椎体高度、L5S1椎间盘高度的等解剖结构测量统计，得出国人腰骶椎解剖结构具体数值范围，并分析腰骶椎前侧血管结构的分布特点，设计出改进型腰骶椎前路钢板的参数指标。2、按照设计参数生产钢板样品，安装在人体脊柱标本后完全符合国人腰骶椎解剖结构特点，且位于腰骶椎前侧手术的“安全空间”内，对腹侧血管不会造成影响和损伤。3、改进型腰骶椎前路钢板经系统的生物力学测试，其在前屈、后伸、侧屈、旋转四种生理运动状态上生物力学稳定性均优于或接近现有的PACH钢板，且操作方便灵活，完全适合国人腰骶椎部位ALIF手术内固定的需要。更多还原

【Abstract】 Background and Purpose：Anterior spina l fixa tion is an effective interna l fixa tion for spina l diseases such asspina l tumors, tuberculosis, vertebra l fractures and spina l disc disease . In various anteriorspina l fixa tion devices, PACH designed and ma nufactured by French SCIENT’X Companyis a widely used interna l fixa tion device in the field of spine surgery in recent years. Thisdevice is used for anterior fixa tion after anterior Lumbosacra l intervertebra l fusion. It hasthe following features : 1. Proper shape to agree with the horizontal curvature of anteriorvertebra l body can help to improve the stability of level pla ne and sagittal pla ne; 2. bila tera lfixa tion provide s three-dimensiona l stability; 3. with a screw security system: elastictitanium bar welded on the steel pla te can bent to allow screw restored after crossingthrough and avoid the screw’s exit; 4. the surface notch allows the pla te attached in thevertebra l body perfectly. However, we gradua lly find some shortcomings of the pla te inclinica l applica tion: 1. This pla te is a single steel pla te with two holes . It needs to impla nttwo steel sheets in the surgica l operation, which makes the process become complica ted. Ifonly one steel sheet is impla nted, the fastness of fixa tion ma y be inadeq uate; 2. the pla te isdesigned on the basis of anatomica l characteristics of foreign race’s spine, and it could notfully conform to the anatomica l characteristics of Chinese spine; 3. no definite standard sare given for the spacing and angle between two impla nted steel sheets, which mea ns thatthe biomecha nica l stability could not be guaranteed. The purpose of this study is to improvethe pla te into an integrated composite pla te with four hole s on the basis of present PACHinterna l fixa tion pla te after statistica l ana lysis of the anatomica l structure of ChineseLumbosacra l vertebrae. Curva ture, length and angle of the improved/mod ified pla te willagree with the anatomica l structure of Chinese Lumbosacra l vertebrae. Biomecha nica l testwill be performed on spine specimens and the biomecha nica l properties sha ll achieve the desired results.MethodMethods1. Measure lumbosacra l angle and the heights of L5 and S1 vertebra l bodies andintervertebra l discs on latera l X-rays of 350 cases of norma l adults’Lumbosacra l vertebrae.Perform statistica l ana lysis upon results of the measurement and obtain usua l numerica lrange of Chinese lumbosacra l structure.2. Design parameters such as height, width, angle and curvature of improved/mod ifiedPACH pla te accord ing to vascular distribution of anterior L5 and S1 vertebra l bodies , so asto have the pla te conform to anatomica l characteristics of Chinese Lumbosacra l vertebrae.3. Manufacture pla te samples and do biomecha nica l tests on huma n spine specimens .Compare biomecha nica l characteristics of improved/mod ified pla te group, PACH pla tegroup and the control group.Results1. After measuring lumbosacra l angle and the heights of L5 and S1 vertebra l bodiesand intervertebra l discs on anteroposterior and latera l films of 350 cases of norma l adults’Lumbosacra l vertebrae, the researchers obtained usua l numerica l range of Chineselumbosacra l structure: height of L5 vertebra l body - (27.06±2.30) mm, height of S1vertebra l body - (22.3±2.8) mm, height of L5 S1 disc - (8.2±0.3) mm, lumbosacra l angle -(129°±5.9°).2. Based on the find ings of anatomica l structure of Chinese Lumbosacra l vertebrae, theresearchers developed optiona l parameters for mod ified PACH interna l fixa tion system:pla te height - 28/32 mm, pla te width - 30 mm, pla te angle - 125°/130°/135°, pla te curvature- arc length 22 mm and chord length 20 mm, screw length - 30/32.5/35/37.5/40/42.5/45 mm,screw dia meter - 5 mm. Ballhead full thread tapping screws are used. And screws tend tohead and tail sides in natural state, with an angle of 18°between the side s.3. The researchers performed bend ing test before testing the specimens : continuingload ing till the set deflection, record ing load - shift curve, and determining shift cha nge ofcontrol group and experimental group under cond itions of anteflexion, postextension andlatera l flexion with 500N load . The results ind ica ted that resista nce to bend ing of mod ified pla te group was superior to the PACH group (P <0.05). Then compression experiment wasperformed. The researchers calcula ted stiffness mea ns of each group under 400N load :PACH group - (87.4±4.2) N/mm, mod ified pla te group - (105.8±7.6) N/mm. The differenceof 20% was statistica lly significa nt (P<0.05). Torsion test was performed in the end. Whenthe turn angle reached 5°, the required torque of spine specimens of mod ified pla te groupand PACH group increased 54.6% and 53.7% respectively compared to control group. Andtorsiona l stiffness of the two was simila r, which mea nt no statistica l difference (P>0.05).ConclusionThe improved/mod ified pla te applies to fusing and fixa tion of tumor, tuberculosis anddisc diseases at L5S1, especia lly suitable for dama ged disc structure and slightly dama ge dsclerotin of vertebra l body. Compared to PACH pla te under the same cond itions, thismod ified pla te has obviously increased resista nce to bend ing and compress ion. In addition,flexion shift and vertica l compression stiffness in all directions of the two groups underlinear load also ind ica tes significa ntly differen ce (P<0.05). This pla te has a reliablebiomecha nica l stability, provid ing an idea l mecha nica l environment for lumbosacra l area .So it is very ind ica ted for fusing and fixa tion at this site.更多还原