基于CT三维重建个性化设计猪股骨髋关节假体与骨髓腔接触率的定量研究

目的基于CT三维重建个性化设计猪股骨髋关节假体与骨髓腔接触率的定量研究。方法选择猪股骨,拍摄实验前正侧位,双斜位片,再运用CT进行横断面扫描,获得CT数据后三维重建。基于CT三维重建数据,运用机器人磨削个性化假体,使其成为与髓腔完全匹配的定制假体。匹配后,拍摄实验后正侧位片,计算定制假体与髓腔接触的骨皮质或者骨松质的表面积以及接触率。结果通过计算,个性化假体近端表面与骨髓腔直接接触率为90.8%,与医疗机器人辅助扩髓组获得的假体表面与骨髓腔直接接触率相近,远较传统手工扩髓组获得的假体近端表面与骨髓腔直接接触率高。结论基于CT三维重建个性化股骨假体与猪股骨髓腔初始固定直接接触率为90.8%,可获得良好的接触率。     

一种自动优选标准型股骨柄的方法

髋关节置换手术中采用标准型假体时,术前只能大致选取假体,术中还要预备多个假体,往往手术时间增长。为了解决这一问题,本文提出一种利用计算机优选标准型髋关节假体的方法。从X线片中获取患者股骨解剖数据。利用这些解剖数据和股骨近端截面平均数据库三维重建患者股骨近端,重建出的股骨近端模型使优选标准假体成为可能。理论分析表明,该方法切实可行。     

中国人股骨头缺血性坏死股骨近端的形态研究

目的 研究股骨头缺血性坏死（AVN）股骨近端的形态,为选择、设计假体提供解剖学依据。方法 收集2004年1月至2008年8月因股骨头缺血性坏死行人工全髋关节置换术的病例186例（281髋）,拍摄股骨近端标准X线正侧位片,测量各节段数据,拟合内外前后四条曲线来描述髓腔形态,并依据年龄和性别分组分析各节段数据的差别。结果 排除由于皮质不清晰和塌陷严重的原因无法获得的完整资料病例59例外,共获得127例AVN患者的股骨近端数据,拟合了内外前后四条曲线,依据年龄分组在股骨内侧曲线远端上存在统计学差异（P<0.05）,依性别分组髓腔各曲线均无统计学差异,平均数据与以往国人正常人数据比较,在小转子及其以上节段存在较大差异。结论 获得了AVN股骨近端在标准X线正侧位片上的大宗数据,拟合了描述髓腔形态的内外前后四条曲线,推断AVN可能是影响股骨近端髓腔形态的独立因素。     

双侧股骨近端对称性及解剖形态的三维重建研究

目的建立正常成人双侧股骨近端的三维模型,分析双侧股骨近端形态并测量解剖形态的相关参数,研究双侧股骨近端的对称性及解剖形态。方法选取50例正常成人双侧股骨近端CT扫描数据,其中男性27例,女性23例;年龄20～65岁,平均年龄44.52岁。扫描参数:扫描层厚0.625 mm,扫描电压120 kV,扫描电流100 mA。扫描范围:自双侧股骨头上10 mm至小转子中点平面下50 mm。将双侧股骨近端CT薄层扫描数据利用Mimics 10.01软件进行三维重建,将左侧股骨与右侧股骨镜像模型相配准,对配准后模型进行三维测量,并测量左右股骨近端的形态参数,使用SPSS 16.0软件对测量结果进行统计分析。结果股骨近端形态和髓腔内部结构有明显的个体差异性,双侧股骨近端形态及内部结构具有高度对称性。股骨头直径为(45.71±4.08)mm,股骨头高度为(53.61±5.43)mm,偏心距为(39.91±5.07)mm,股骨颈中央直径为(36.71±3.75)mm,颈干角为(127.88±6.28)°,股骨颈长度(46.61±4.74)mm,小粗隆中点所在平面的髓腔内径为(26.21±4.59)mm,其中偏心距、颈干角与白种人形态参数相比,差异有显著统计学意义(P<0.01);提供了一种验证双侧股骨对称性的新方法。结论正常成人双侧股骨内外部形态存在一定的对称性,变异较小,为股骨形态的测量提供理论依据;三维重建更利于对股骨近端形态参数的测量;新配准方法的提出对于临床中股骨近端骨折的诊治具有重大意义。     

股骨近段髓腔解剖参数测量与不同类型人工股骨假体的选择

目的　对414例股骨近段髓腔解剖特征的X线影像学测量,为临床合理选择股骨假体提供参数。 方法　随机选择414例苏州大学附属第一医院骨科2005年3月～2008年12月期间股骨近端DR影像资料（DICOM格式）,用Dicom viewer软件测量10项股骨近段髓腔径长参数和5项形态参数,分析各参数的特点、相关性及与性别、年龄的关系。 结果　(1)年龄因素（女性）和峡部内径显著正相关,随着年龄增长,小粗隆中点下方20 mm处髓腔至峡部髓腔内径变宽大,整个股骨近端髓腔呈宽而直的烟囱型。(2) MCFI集中于1.8～2.4,占总的被测人群68.08%。（3）本组所测CFI,根据Nobel分型,烟囱型髓腔占13.0%,正常型髓腔占72.5% ,漏斗型髓腔占14.5%。（4）MCFI和CFI显著正相关,MCFI和DCFI无显著相关性;CFI和DCFI、股骨远端髓腔开大角度显著正相关,CFI和峡部内径显著负相关;DCFI和股骨远端髓腔开大角度显著正相关。 结论　(1)股骨近端髓腔形态、大小变异较大,国人之间及与欧美白种人群之间均存在一定的差异。(2)MCFI、CFI、DCFI对描述股骨近端髓腔形态各有侧重,三者结合髓腔径长参数能更准确、细致地刻画髓腔形态。     

股骨近端髓腔闪烁指数与股骨颈骨密度的关系

背景：髋关节成形患者具有较高的骨质疏松症患病率,骨质疏松症影响假体存活率,髓腔闪烁指数与骨密度均随年龄变化。 目的：探讨股骨近端髓腔闪烁指数与股骨颈骨密度的关系,提高对骨质疏松症的关注。 方法：回顾性研究57例髋关节成形患者的骨盆X射线正位片的股骨近端髓腔闪烁指数和股骨颈骨密度,探讨二者的相关性。 结果与结论：57例髋关节成形患者的股骨近端髓腔闪烁指数为1.8-4.8(3.1±0.7);髓腔闪烁指数< 3者23例,髓腔闪烁指数为3-4.7者33例,髓腔闪烁指数> 4.7者1例。年龄对髓腔类型有影响,> 60岁组烟囱型髓腔显著性多于≤ 60岁组,髓腔闪烁指数≥ 3组的骨密度显著高于髓腔闪烁指数< 3组。随着年龄增高,股骨颈骨密度降低,> 60岁组患者的股骨颈骨密度为(0.590±0.092) g/cm2,显著低于≤ 60岁组患者的股骨颈骨密度(0.751±0.235) g/cm2(P =0.000),比较发现随骨密度降低,髓腔闪烁指数均值变小。因此股骨颈骨密度与髓腔闪烁指数显著相关。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

自由变形算法在快速骨重建中的应用

本文在传统自由变形算法的基础上,提出了一种应用在人体骨骼快速三维重建的单位自由变形(FFD)算法。文中以股骨为例,依据单位自由变形算法实现利用两张X线片对股骨进行快速三维模型重建的工作。利用专业C臂机上获取两张正交方向拍摄的X线片,并保留拍摄参数;借助X线片提供的轮廓信息对标准模型进行个性化三维重建。文中通过点配对算法建立了X线片外轮廓与三维标准模型外轮廓之间的对应关系,将传统自由变形算法进行简化设计,利用单位自由变形控制格对标准模型进行重建,最终使得X线片外轮廓与标准模型外轮廓一致,从而获得个性化的股骨三维模型。选取35例尸体股骨样本设计外形精度、鲁棒性和重建速度实验,最终得到全骨的二维点配对平均时间为20s,平均重建时间为112s;三维模型的外形平均误差为0.52mm,且精度和速度均保持稳定,具有良好的鲁棒性。本研究将传统自由变形算法简化应用到重建模型算法中,使得重建时间减少,重建精度达到传统方法要求,同时具备良好的可重复性,在临床应用和相关科学研究中具有很好的应用前景。     

标准截面形状定制型股骨柄假体设计

目的 介绍一种标准截面形状定制型股骨柄假体结构以及自行开发的设计方法。方法首先利用DICOM格式的患者股骨CT图像,重建患者股骨近端模型;根据重建出的患者股骨近端模型构建股骨柄假体匹配段矩形的截面边界,并在矩形截面边界内用简单的线条初步构建出假体的截面轮廓曲线;利用股骨近端模型对初步设计出的股骨柄假体进行验证,并通过调整设计参数使最终设计出的个性化股骨柄假体与患者股骨髓腔相匹配。结果 定制型人工髋关节股骨柄假体采用标准截面形状,便于快速设计出个性化假体,而且设计操作简单。参数化程序设计大大降低了个性化股骨柄假体的设计工作量。结论 标准截面形状定制型股骨柄假体的设计将有助于提高定制型人工髋关节置换手术的成功率,促进定制型股骨柄假体在临床上的应用,进一步提高患者的生活质量。     

扭转力传递的非骨水泥髋关节假体设计、制作及实验分析

背景:人体股骨髓腔具有扭转的解剖结构,如果股骨髓腔的扭转结构被复制到假体的柄体上,当假体插入髓腔并在假体上加载力时,假体将加载的力转换成股骨髓腔对柄体的扭转力并将该力传递到股骨近端。目的:优化股骨近端的力传递,避免假体近端应力遮挡。方法:利用人股骨标本的CT图片重建股骨髓腔的3D模型,将该3D模型作为柄体的设计模型。将定制式柄体模型与标准假体的近端模型拼合,形成定制式假体。采用机器人磨削技术制作定制式假体,并将定制式假体与标本股骨髓腔匹配。利用有限元仿真和实验方法分析假体上加载的力与假体近端扭转微动的关系。结果与结论:仿真和实验结果表明,股骨髓腔与柄体匹配的扭转结构,可有效地将假体上加载力以扭转力的形式传递到股骨近端,假体近端的扭转微动与柄体的微动相关,而柄体的微动可通过改变柄体与髓腔的匹配区大小得到控制。     

髓腔延长顺行交锁髓内钉治疗股骨远端骨折基础与应用研究

目的探讨髓腔延长顺行交锁髓内钉治疗股骨远端骨折的临床疗效。方法：(1)107例成人股骨X线正、侧位片观测髓腔形态结构特点；(2)在X线片上测量估算髓内钉可达到股骨远端的最远距离，复位骨折，术中X线临测扩髓延长股骨远端髓腔至关节面上10～15mm，采用髓腔延长顺行交锁髓内钉治疗股骨远端骨折12例，2例不稳定骨折髓内钉同定后均加用小钢板单侧骨皮质螺钉同定。结果：12例骨折均达解剖复位或接近解剖复位，全部愈合。结论：髓腔延长顺行交锁髓内钉治疗股骨远端骨折具有创伤小，基本不损伤膝关节，术中出血少，稳定性好，膝关节功能恢复良好，骨折愈合率高等优点，值得临床推广和应用。     

Measurement of femoral neck anteversion in 3D. Part 2:3D modelling method

Femoral neck anteversion is the torsion of the femoral head with reference to the distal femur. Conventional methods that use cross-sectional computed tomography (CT), magnetic resonance or ultrasound images to estimate femoral anteversion have met with several problems owing to the complex three-dimensional (3D) structure of the femur. A 3D imaging method has been developed that virtually measures femoral anteversion on the 3D computer space with continuous CT slices; this 3D method provides more accurate and reliable results than conventional 2D CT measurements. A 3D modelling method is devised for the measurement of femoral neck anteversion. This method has advantages over the 3D imaging method, such as shorter processing time, reduced number of slices and an objective result compared with the 3D imaging method. The results of the 3D modelling method are compared with the conventional CT methods (2D CT method and 3D imaging method) using 20 dried femurs.     

基于CT断层图像重建股骨头缺血性坏死髋关节的三维结构

目的探索通过虚拟现实技术寻求快速准确重建股骨头缺血性坏死髋关节三维结构的方法。方法基于髋关节的64排螺旋CT连续断层二维图像,M im ics软件分别重建髋臼、近端股骨、股骨颈及股骨头病变组织的三维可视化结构。结果 M im ics医学图像处理软件对髋关节CT扫描的D icom格式数据进行三维重建图像结构清晰,可真实再现髋臼和股骨近端的结构,并且能够对病变组织部位予以定位,对病变组织体积进行计算。结论 M im ics软件根据CT扫描所得的D icom原始数据能准确重建股骨头缺血性坏死髋关节的三维立体结构,为股骨头缺血性坏死髋关节骨质的评估及治疗方案的选择提供了客观的依据。     

数字骨科技术在股骨转子间骨折植入物修复前的规划作用

BACKGROUND: Intertrochanteric fractures can be generally treated by surgical treatment. Along with deep research on the biomechanics of the proximal femur, proximal femoral locking compression plate appears recently. The locking plate fixation is not strong, can reduce the local stress shielding, and maintain optimal system stability, but fracture fixation failure often occurs due to the inappropriate choice of nail plate.  OBJECTIVE: To evaluate the value of digital orthopedics technology in preoperative planning in locking plate fixation for intertrochanteric fracture. METHODS: Forty intertrochanteric fracture patients receiving CT tomography femur upper segment were selected and divided into two groups. In the conventional group, after reading X-ray films and CT images, patients received locking plate fixation. In the computer planning group, before repair, fracture model was established using Mimics software to segment fracture fragments, simulate operation reset and 3-matic software was used to reconstruct locking plate and screws. Locking plate was assembled with Mimics to obtain the best plate position, best screw angle and screw length. Proximal femoral locking compression plate fixation was performed. Fluoroscopy times, operation time, blood loss and fracture healing time were compared in both groups. RESULTS AND CONCLUSION: Three-dimensional models of proximal femur were reconstructed, and a series of data were obtained. The optimal position of each plate was obtained from each patient. The screw length was predicted, so preoperative operation planning was realized. All patients were followed up for 6-20 months. Fluoroscopy times, operation time, and blood loss were significantly less in the computer planning group than in the conventional group (P < 0.05). No significant difference in fracture healing time was detected between the two groups (P > 0.05). These findings suggest that digital orthopedics technology used in intertrochanteric fracture can simulate the locking plate position, determine the screw placement angle and length of the screw in advance, and reduce fluoroscopy times, operation time, blood loss and screw position misalignment.       

大龄髋脱位儿童股骨颈前倾角变化与骨骺应力的有限元分析研究

目的运用有限元分析方法,对正常及发育性髋关节发育不良(DDH)儿童股骨头近端骨骺生长板同承力情况下横断面的应力进行研究,为股骨近端截骨矫形手术提供理论依据。方法按照Tonnis分型选取40例DDH大龄儿童,其中男性11例,女性29例;年龄8～12岁,平均年龄10.14岁。分为半脱位及全脱位组。20例非DDH儿童作为正常对照组,其中男性11例,女性9例;年龄8～12岁,平均年龄10.10岁。通过二维CT技术测定各组股骨颈前倾角,通过有限元分析软件分析股骨头近端骨骺生长板在横断面上的应力情况。结果正常对照组股骨头近端骨骺生长板横断面上前内侧及后外侧的切应力和静压力相当。半脱位组及全脱位组股骨头近端骨骺生长板横断面上前内侧静压力大于后外侧,而前内侧的切应力小于后外侧。股骨颈前倾角与前后两侧静压力差呈正相关,与前后两侧切应力差呈负相关。结论 DDH大龄儿童的股骨颈前倾角随生长发育而增大。传统的股骨近端旋转截骨术在纠正发育性髋脱位儿童股骨骨骺异常应力,保证正常的头臼关系中有重要的临床意义。     

Determining the degree of cortical bone asymmetry in bilateral, nonpathological, human femur pairs

When testing the effects of a femoral component on cortical bone following total hip arthroplasty, the patient's implanted femur is often compared with his/her contralateral nonimplanted femur, with differences attributed to the femoral component. However, if normal anatomical differences exist between bilateral femurs, they need to be quantified in order to validate whether the differences between implanted and nonimplanted bilateral femurs are due to the implant or possibility due to intrinsic differences before implantation. This study quantified the geometric properties of cortical bone shape between seven pairs of bilateral, cadaveric, human femurs. The null hypothesis tested stated that the bilateral femurs would not be significantly different in cortical bone geometry. Digitized images of cortical bone cross-sections taken at percent biomechanical lengths (levels 1-8) were used to calculate bone geometry measurements. The paired t-test showed that the only significant difference was in the location of principal axes at the most proximal location, level 1 (p = 0.015). All other measurements and levels were not significant with percent differences less than 6.6%. In conclusion, the data supports attributing cortical bone shape differences between implanted and contralateral nonimplanted femurs in levels 2-8 to the presence of the implant when the significant differences are greater than 6.6%.     

Parametric subject-specific model for in vivo 3D reconstruction using bi-planar X-rays: application to the upper femoral extremity

Although feasibility of accurate 3D reconstruction of the proximal epiphysis of the femur from biplanar X-rays (frontal and lateral) has been assessed, in vivo application is limited due to bone superposition. The aim of this study was to propose a specific algorithm to get accurate and reproducible, low dose in vivo 3D reconstruction. To achieve this goal, a parametric subject-specific model was introduced as a priori knowledge. This geometric model was based on a database based on proximal epiphysis of 60 femurs. The accuracy was estimated using comparisons to CT scans on 13 cadaveric femurs, then in vivo intra- and inter- observer reproducibility was assessed using a set of 23 femurs. The mean for the relative difference was 0.2 mm for the in vitro 3D accuracy. The mean error was 1.0 mm with maximum value of 5.1 mm in ideal conditions (in vitro). The confidence interval for the inter-observer reproducibility was within +/-2.2 mm. This method gave us a reproducible tool in order to get in vivo 3D reconstructions of the femur proximal epiphysis from biplanar X-rays.     

Measurement of femoral neck anteversion in 3D. Part 1: 3D imaging method

Femoral neck anteversion is the torsion of the femoral head with reference to the distal femur. Conventional methods that use cross-sectional computed tomography (CT), magnetic resonance or ultrasound images to estimate femoral anteversion have met with several problems owing to the complex, three-dimensional (3D) structure of the femur. These problems include not only the difficulty of defining the direction of the femoral neck axis and condylar line but also the dependency upon patient positioning. In particular, the femoral neck axis, the direction of the femoral head, known as the major source of error, is difficult to determine from either a single or several two-dimensional (2D) cross-sectional images. A new method has been devised for the measurement of femoral anteversion using the 3D imaging technique. 3D reconstructed CT images from the femoral head and trochanter to the distal femur are used to measure the anteversion. It is necessary to remove the soft tissue from the CT images and extract just the bone part. Then, the femoral anteversion is measured from a computer-rendered femur image. The 3D imaging method is compared with both the conventional 2D method and the physical method using 20 dried femurs. For the physical method, which is used as a reference value, a special apparatus is devised. The average difference between the results of the physical method and those of the 2D CT method is 5.33°. The average difference between the results of the physical method and those of the 3D imaging method is 0.45°. Seventy-four patients, who suffer from toe-in-gait disease, are tested to compare the 3D imaging method with the conventional 2D CT method. The average difference between the 2D and 3D methods is 8.6°, and the standard is 7.43°. This method provides a very accurate and reliable measurement of femoral anteversion, as it is virtually equivalent to the direct measurement of bisected dried femur in vitro.     

股骨近端髓腔三维解剖测量

目的测量国人股骨近端髓腔形态,探讨适合国人的股骨近端髓内钉设计方案。方法选取120侧(男性55侧,女性65侧)正常成人单侧股骨近端CT扫描数据,利用Mimics图像分析软件对股骨近端的髓腔内径及髓腔开大指数行三维解剖测量,研究其与身高、年龄之相关性,及性别差异,并与国内外数据进行综合比较。结果以小粗隆中点为参考点(T),男、女性组髓腔内径分别为:T+20(44.79±5.42)mm和(39.79±4.96)mm;T+10(34.00±3.64)mm和(32.06±3.29)mm;T(26.93±3.71)mm和(24.18±3.31)mm;T-20((18.65±2.96)mm和(18.21±2.60)mm;峡部(10.40±1.45)mm和(10.15±1.05)mm。男女组T+20、T+10、T处比较存在显著性差异(P0.001);T-20、峡部处两组间比较无显著性差异(P0.05)。身高与各组间数据存在正相关关系,存在统计学意义(P0.05),与干骺端髓腔开大指数呈负相关,存在统计学意义(P0.05);偏相关分析年龄与髓腔内径参数间存在正相关关系,存在统计学意义(P0.05),而与各组髓腔开大指数间无明显相关性。结论东西方人、男女性之间股骨近端髓腔内径存在显著性差异,在治疗粗隆间骨折时需要充分评估其股骨近端内径,选用合适的内固定器械。