The Design And Biomechanical Study Of Transverse Compression Internal Fixation System Of Atlas

Part I The analysis of the atlas specimens were observed and related anatomic parameter measurementObjective: Through the atlas of dry bone specimen observation and literature review clearly atlas pedicle definition and ideal pedicle screw channel establishment, through the measurement and analysis of the related anatomic parameters for the design of the internal fixation system provides theoretical parameters.Methods: 20 Atlas of dry bone specimens of the overall and section observation and by the definition of the literature review clearly atlas pedicle and establish the ideal of vertebral pedicle screw. By pedicle definition and to establish the ideal pedicle nails on atlas single section horizontal compression internal fixation system design and production related data were measured and that data for statistical analysis.Results: the pedicle width(the posterior arch and the lateral junctio n block is the isthmus width, diameter(width) pedicle isthmus canc ellous bone of vertebral arch length(width), ideal pedicle screw th rough the arch of the distance and the median sagittal plane to theinsertion point within the limit of the anterior portion of the spina l canal in the rear section(by two the ideal of pedicle screw chan nel on the lateral point line, the line and the posterior arch of the intersection to the posterior median sagittal plane distance), the med ian sagittal plane to the needle point in the section through the two limit( pedicle screw on the ideal spinal anterior posterior most l ateral point line, parallel line, the the line through the ipsilateral tra nsverse foramen and posterior arch of the parallel line of the inters ection to the posterior median sagittal plane distance), the median s agittal plane to the ideal entry point distance(the median sagittal pl ane to the ideal screw and posterior arch of posterior intersection d istance), ideal screw length( pedicle Nail road through the length of the bone), pedicle height(atlas posterior arch and the lateral m ass of connecting part that is in the middle of the isthmus height),needle pitch of vertebral arch pedicle diameter height(pedicular m easurements at the height of cancellous bone height), vertebral arch posterior height(ideal into the needle point of vertebral arch poste rior height), the ideal edge distance, posterior arch of vertebra arter y notch shift line and the ideal into the needle point distance, inter nal angle( α angle): ideal pedicle screw channel head and sagittal p lane into an acute angle and anteversion angle(β angle): ideal pedi cle screw tract head of atlas and the articular surface of the acuteangle. Respectively:9.3mm、5.07mm、5.43mm、17.89mm、25.15mm、22.50mm、29.98mm、5.24mm、4.12mm、6.14mm、2.11mm、3.08mm、29.96°、5.09°.Conclusion: through the atlas of dry bone specimen obser vation and literature review clearly atlas pedicle definition and ideal pedicle screw path established by Atlas single section horizontal co mpression internal fixation system and design related anatomic para meters measurement and analysis of theoretical parameters were obt ained for the design of the internal fixation system.Part II The analysis and measurement of atlas CT imaging observation and related imaging parametersObjective: Through the observation on the atlas CT three-dimensional reconstruction and multi planar reconstruction images to further clarify the pedicle definition and ideal pedicle screw path establishment, the atlas single section horizontal compression internal fixation system and design of measurement and analysis of CT image parameters provides further theoretical parameters for the design of the internal fixation system.Methods:The atlantoaxial CT imaging on 40 normal adult data of3 D and multiplanar reconstruction. Three dimensional overall image and profile are observed, and then the relative diameter and angle of the study are measured. The statistical analysis on the measurement results and compared with the measurement results of the first part.Results: The pedicle width(the posterior arch and the lateral junction block is the isthmus width, diameter(width) pedicle isthm us cancellous bone of vertebral arch length(width), ideal pedicle s crew through the arch of the distance and the median sagittal plane to the insertion point within the limit of the anterior portion of th e spinal canal in the rear section(by two the ideal of pedicle scre w channel on the lateral point line, the line and the posterior arch of the intersection to the posterior median sagittal plane distance), the median sagittal plane to the needle point in the section through the two limit( pedicle screw on the ideal spinal anterior posterior most lateral point line, parallel line, the the line through the ipsila teral transverse foramen and posterior arch of the parallel line of th e intersection to the posterior median sagittal plane distance), the m edian sagittal plane to the ideal entry point distance(the median sa gittal plane to the ideal screw and posterior arch of posterior inters ection distance), ideal screw length( pedicle Atlas(via a needle i nto the vertebral artery, the distance from the edge of the needle in to the needle into the inner diameter of the central through the pin tract bone length), pedicle height(posterior arch and lateral mass of connecting isthmus height), pedicle height(measured pedicle heig ht bone cancellous height), vertebral arch posterior height(ideal poi nt of vertebral arch posterior height), the ideal pitch of vertebral ar ch of atlas posterior arch notch transitional and ideal point distance,Mahalanobis established pedicle screws into the needle point) to th e median sagittal plane distance and angle( α angle): ideal pedicle nail head, and the median sagittal plane the acute angle and antev ersion angle(β angle): ideal pedicle screw channel head and articul ar surface at an acute angle. Respectively(x + s mm or °):9.32±0.85、5.00±0.77、5.41±0.94、18.66±0.75、25.14±0.91、22.48±0.94、30.41±0.74、5.10±0.83 、4.15±0.63、6.18±1.04、2.05±0.86、3.10±0.77、19.55±0.80、30.06±1.59、5.00±0.89.Conclusion: Through the observation on the atlas CT three-dim ensional reconstruction and multi planar reconstruction images to fur ther clarify the pedicle definition and ideal pedicle screw path estab lishment, through of measurement and analysis of CT image parame ters related to the design of the atlas single section horizontal comp ression internal fixation system for the internal fixation system desi gn obtained the further theoretical parameters.PARTIII The atlas transverse compression fixation system design and finite element analysisObjective: According to the theoretical parameters of the first and the second part, according to our design concept, we can not only maintain the stability of the upper cervical spine, but also not to sacrifice the normal physiological function of the upper cervical spine. And through the relevant software to simulate the internal fixation system to evaluate the mechanical properties of the system.Methods:The data of the first and the second parts were further analyzed by frequency distribution chart, which provided more accurate specification parameters for each part of the fixing device. Atlas of single segment length and transverse compression screw thread length fixation system by pedicle screw length. Pedicle screw thread diameter is determined by the height of the pedicle. The atlas pedicle screw diameter by the pedicle of the cancellous bone height. For the design of atlas pedicle screw thread internal taper thread, atlas pedicle screw tail nut supporting design for double nut, transverse lock screw tail design for a font grooves. Transverse arc-shaped pressure device is designed in accordance with the posterior arch of the atlas of the curvature, the adjusting scope according to the measured atlas pedicle needle point between two points of maximum distance and minimum distance,adjustable maximum value for the measured atlas pedicle into the needlepoint between two points of maximum distance, minimum is the minimum distance between two points of the measured. Then through the software on the computer model design, finite element analysis and design of the model, to understand whether the mechanical properties can meet the practical needs of the clinical. The principal manufacturers of products.Results: According to our design philosophy and of the parameters,we by software in computer design to meet the requirements of the internal fixation devices and simulation test of mechanical properties meet the clinical requirement. Finally, commissioned by the manufacturers to meet the requirements of the product.Conclusion: Our design idea is advanced, reasonable structure, can meet the needs of clinical practice, can produce a product, prepare for the next experiment of biomechanics.Part IV Single screw pull-out test of three different directions of atlas screw placementObjective: Through to the atlas posterior three different pedicle screw insertion techniques: Ma, TAN and the design of needle insertion of single screw pullout a test to determine which method of placing screw pullout strength better.Methods: The size of the 15 patterns are basically consistent, bone specimens arch height >4mm atlas atlas vertebral artery after. Atlas pedicle screw 30 pieces(self-designed, commissioned by the entrusted production of Jiangsu Jinlu group medical system Machinery Co., Ltd.):3.5 mm diameter, thread length of 25 mm, pitch 2mm, thread mechanism within the cone. The 15 atlas dry bone specimens of 30 pedicle were randomly divided into three groups, each 10 pedicle, respectively,according to Markov, TAM and the design of pin tract for pedicle screw.The maximum pullout strength test was performed using the biomechanical instrument, and the maximum pullout strength of the same screw was observed.Results: Respectively according to Ma, Tan, the research and design of nail nailing, screw axial maximum anti pull output respectively(N):275.62±1.06、280.3±1.35、278.28±1.17.Conclusion: According to Ma, Tam, the research and design of nail nailing, single screw axial maximum pull-out output without significantdifference.Part V The overall pull out test of the three kinds of internal fixation systemObjective: By of posterior three different pedicle screw insertion techniques: Markov, TAM and the design of needle insertion set of fixed system of anti pulling a test to determine what kind of screw placement of internal fixation system more firmly.Methods: 30 atlas dry bone specimens were randomly divided into three groups,(n = 10), 30 sets of the design of the internal fixation system(specifications exactly) were randomly divided into 3 groups(n = 10).According to the design of the needle point and the direction of the needle in the needle point and the direction of the needle. The same transverse connection device is installed respectively(by adjusting the angle of the horizontal connecting device of the horizontal connecting device when the installation is installed. Then carry out the whole anti pull out test, record the maximum resistance to pull out.Results:Respectively according to the Mao, Tam, the research and design of nail pedicle screw, internal fixation system in the overall axial maximum pullout resistance of respectively(N):1125.2±65.3、863.4±32.8、1468.28±78.9.Conclusion: Ma, Tam, the study design nail pedicle screw,internal fixation system in the overall axial maximum pullout strength.The research and design of nail implanted in this study, the design offixed system uplift maximum output, indicating that the atlas to be firmly fixed.Part VI Contrast test of transverse compression internal fixation system and screw rod fixation systemtransverseObjective: Unstable atlas fractures specimens were single section lateral pressure in a fixed system fixation for reconstruction of the skull ring and biomechanical experiments, for future clinical research to provide theoretical support.Methods: Eight complete occipital cervical specimens were divided into two groups, which a group of atlas single section lateral pressure in a fixed group: in the whole atlas, C1 unstable fractures and atlas lateral pressure in a fixed state under the same loading load were occipital cervical activity comparison. Another group of nail stick internal fixation group: the same in three states to carry out the same comparison. Through the comparison of the effect of maintaining the stability of atlas atlas instant single transverse compression fixation system evaluation.Results: Atlas single section lateral pressure in a fixed system group:before and after the whole Atlas of occipital cervical flexion extension,right and left flexion, rotation around the amplitude respectively(o) :12.32±2.31 、13.44±2.80 、11.25±1.52、11.48±1.35 、53.84±3.25 、54.16±2.96;unstable fracture model group(o): 26.53±2.37、26.21±3.76、21.56±2.12、 21.21±2.45 、66.18±2.96 、69.52±3.25;single section lateral pressure fixation group is(o) :14.84±1.54 、14.30±2.82 、12.43±1.35 、12.65±1.42 、56.31±3.21、57.15±2.98.Atlas single section lateral nail rod internal fixation system group: before and after the whole Atlas of occipital cervical flexion extension, right and left flexion, rotation around the amplitude respectively(o) :11.56±2.42、 11.44±2.38、 11.38±1.47、 11.59±1.26、 53.47±3.56、 54.23±2.85;unstable fracture model group(o)27.52±2.06 、26.18±3.54、21.62±2.06、 21.05±2.32 66.26±2.58 、 69.48 ±3.16; single screw rod internal fixation group is(o):15.87±1.64、14.25±2.76、12.26±1.18、12.26±1.35 、56.38± 3.12 、 57.36 ± 2.35. Group compared with unstable fracture in different direction of the neck pillow is greater than the intact state; atlas lateral compression internal fixation system state pillow neck in all directions of the scope of activities are less than complete unstable fracture; atlas lateral compression internal fixation system state under the direction of the movable range and full basic state are, the activity range of each direction comparison showed that the P > 0.05, no statistical difference. Atlas pedicle screw fixation group occipital cervical range:unstable fracture > > state of complete nail fixed state bar. There were statistically significant differences between the two groups. The range of activities of the fixed group of lateral compression fixation group were compared with the two groups(p<0.05).Conclusion: Atlas lateral compression internal fixation system of unstable atlas fractures Bone Ring reconstruction significantly enhancedoccipito atlanto- axial complex stability and can meet the needs of normal physiology. The atlas single screw rod system of atlas fixation can also increase the stability of C1 unstable fractures...