广东地区人群颞下颌关节解剖参数的三维分析

目的 对广东地区不同人群的下颌骨及髁突解剖参数进行三维分析。 方法 选取就诊于南方医科大学口腔医院的患者265名,利用CBCT分别测量男性和女性的髁突长度、髁突高度、下颌升支高度、下颌体高度以及下颌神经进入下颌升支的位置。 结果 所有患者髁突的平均长度（内极-外极）二维测量为19.2 mm、三维测量为20.3 mm,男性比女性长3.6 mm,两者之间无统计学差异。下颌骨高度、髁突高度和下颌升支高度分别为59.6 mm,22.8 mm和38.3 mm,其中下颌骨高度男性比女性长6.4 mm,两性之间有统计学差异。下颌升支的宽度、下颌小舌到升支前缘的距离和下颌小舌到升支后缘的距离分别为：29.4 mm,14.8 mm及14.6 mm,男女之间均无统计学差异。 结论 CBCT测量颞下颌关节有着更显著的准确性,本实验结果丰富了中国人群下颌骨解剖数据,有助于开发适合广东地区的人工颞下颌关节。 【关键词】 下颌骨; 髁突; CBCT; 人工颞下颌关节     

Errors in using fixed flexion facet centers to determine tibiofemoral kinematics increase fourfold for multi-radius femoral component designs with early versus late decreases in the radius of curvature

BackgroundOne method to determine tibiofemoral joint kinematics following total knee arthroplasty (TKA) is to quantify movement of the anterior-posterior (AP) position of the flexion facet center (FFC) on each femoral condyle relative to the tibia during knee flexion. The primary objective was to determine how closely AP positions of fixed FFCs approximate AP positions of variable FFCs of multi-radius femoral component designs with early versus late initial transition angles (i.e. earliest flexion angle where the radius of curvature decreases markedly).MethodsVariable FFCs were determined for each femoral condyle as centers of best-fit circles to 20° segments of the sagittal profile from 0° to 120° of flexion in 15° increments. The fixed FFC of each condyle was the center of the best-fit circle from 0° to 120° of flexion. Errors in AP positions were differences between AP positions of fixed FFCs and variable FFCs.ResultsFor profiles with a late initial transition angle of 120° of flexion, the root mean square error (RMSE) was limited to 0.7 mm. For profiles with an early initial transition angle of 60° of flexion, the RMSE was 2.7 mm, nearly a fourfold increase.ConclusionsTo determine whether fixed FFCs can be used to indicate AP positions of femoral condyles with minimal RMSE < 1 mm, the initial transition angle should be found as an important first step. Condylar AP positions for designs with an early initial transition angle should not be approximated by AP positions of fixed FFCs when determining tibiofemoral kinematics.     

股骨内髁参数对单髁置换中截骨及假体设计的参考意义

BACKGROUND: Knee-parameter measurements play an important role in the designing of the knee prosthesis. Currently, we have more and more research of the total knee replacement, while uni-condylar knee replacement study is few.  OBJECTIVE: To obtain the parameters of the normal femoral condyles and explore its correlation with osteotomy and prosthesis design of the knee joint during uni-condylar knee replacement. METHODS: Normal knee joints of 60 cases (60 knees) were selected. We measured the parameters by using thin-section CT scan and post-processing techniques, including arc diameter of the lowest point of the femoral condyle on the coronal plane, arc diameter of the distal point of the posterior condyle of the femur on the transverse plane, arc diameter of the distal point of the posterior condyle of the femur on the sagittal plane, and arc diameter of the lowest point of the femoral condyle on the sagittal plane, and analyzed the correlation with sex and height.  RESULTS AND CONCLUSION: The diameter of the arc that passes through the lowest point of femoral medial condyle in the coronal plane was (42.685±1.389) mm. The diameter of the arc that passes through the farthest point of posterior of femoral medial condyle in the cross-section was (42.732±1.440) mm. The diameter of the arc that passes through the lowest point of femoral medial condyle on the sagittal plane was (45.473±1.332) mm. The diameter of the arc that passes through the farthest point of posterior of femoral medial condyle on the sagittal plane was (42.587±1.446) mm. The results illustrate that knee condyle related parameters were positively correlated with height. Parameters in males were significantly greater than in females. The diameter of the arc that passes through the lowest point of femoral medial condyle on the sagittal plane was significantly larger than that of the farthest point of femoral posterior medial condyle on the sagittal plane (P < 0.001). There was no significant difference among the diameter of the arc that passes through the lowest point of femoral medial condyle on the coronal plane, the diameter of the arc that passes through the farthest point of posterior of femoral medial condyle on the cross-section and that of the farthest point of femoral posterior medial condyle on the sagittal plane.       

正常成人颈椎间盘相关参数测量及意义

目的 提出椎间盘的测量方法并测量正常成人颈椎间盘相关参数,为设计人工颈椎间盘提供参数依据。 方法 从深圳市第二人民医院和深圳市南山医院提取正常成人颈椎MRI数据219例,测量C4/5、C5/6、C6/7 3个颈椎间盘的椎间盘前高,中高,后高,椎间角,矢径及横径6组数据并作统计学分析计算。 结果 颈椎间盘前高为（4.27±0.73）mm,中高为（5.63±0.83） mm,后高为（3.24±0.59）mm,颈椎间盘角度为（4.73±1.57）°,颈椎间盘矢径为（15.50±1.70）mm,横径为（22.20±2.56）mm。 结论 上述6组数据存在性别间的显著差异性和节段间的显著差异性,设计人工颈椎间盘应设计一系列不同参数的假体以满足不同性别不同颈椎节段的需求。     

Predicting the effects of knee focal articular surface injury with a patient-specific finite element model

Successful focal articular surface injury (FAI) repair depends on appropriate matching of the geometrical/material properties of the repaired site, and on the overall dynamic response of the knee to in-vivo loading. There is evidence linking the pathogenesis of lesion progression (e.g. osteoarthritis) to weightbearing site and defect size. The paper investigates further this link by studying the effects of osteochondral defect size on the load distribution at the human knee. Experimental data from cadaver knees (n = 8) loaded at 30° of flexion was used as input to a validated finite element (FE) model. Contact pressure was assessed for the intact knees and over a range of circular osteochondral defects (5 mm to 20 mm) at 30° of flexion with 700 N axial load. Patient specific FE models and the specific boundary conditions of the experimental set-up were used to analyze the osteochondral defects. Stress concentration around the rims of defects 8 mm and smaller was not significant and pressure distribution was dominated by the menisci. Experimental data was confirmed by the model. For defects 10 mm and greater, distribution of peak pressures followed the rim of the defect with a mean distance from the rim of 2.64 mm on the medial condyle and 2.90 mm on the lateral condyle (model predictions were 2.63 and 2.87 mm respectively). Statistical significance was reported when comparing defects that differed by 4 mm or greater (except for the 5 mm case). Peak rim pressure did not significantly increase as defects were enlarged from 10 mm to 20 mm. Peak values were always significantly higher over the medial femoral condyle. Although the decision to treat osteochondral lesions is multifactorial, the results of this finite element analysis indicate that a size threshold of 10 mm, may be a useful early adjunct to guide clinical decision-making. This modified FE method can be employed for in-vivo studies.     

Electrically communicating three-dimensional cardiac tissue mimic fabricated by layered cultured cardiomyocyte sheets

Calcium hydroxyapatite ceramics (CHA) are nontoxic materials, provoke little reaction from tissues, and by virtue of these properties represent a good starting point for creating bone substitutes. Although several porous CHAs have been used clinically, there have been few reports that CHA is fully replaced by newly formed bone, which may be due to its structure and the limited connectivity between pores. We recently developed a fully interconnected porous CHA (IP-CHA) by adopting a "foam-gel" technique. Structural analysis by scanning electron microscopy revealed that IP-CHA had spherical pores of uniform size that were interconnected by window-like holes. The surface of the wall structure was smooth, and hydroxyapatite particles were bound tightly to one another. Most of the interpore connections of IP-CHA ranged from 10 to 80 microm in diameter (average, 40 microm). When the cylindrical IP-CHA (diameter, 6 mm; height, 15 mm) was implanted into a rabbit femoral condyle, bone, and bone marrow with abundant vessels formed deep in the pores through the interpore connections. Within a period of 6 weeks, new bone had formed and penetrated to a distance of 3 mm from the surface of the IP-CHA implant. Furthermore, a compression test at 9 weeks revealed that the implanted IP-CHA steadily increased in strength to more than double the value of the initial test. These results indicate that the IP-CHA may have clinical utility as a superior bone substitute.     

Gender analysis of the anterior femoral condyle geometry of the knee

BackgroundNo study has used 3-D anatomic knee models to investigate the gender differences in anterior femoral condyles. Therefore, this study aims to determine the morphologic differences between genders in anterior femoral condyles of the knees using 3-D anatomic knee models.MethodsNinety-six male and sixty-five female 3D anatomic knee models were used to measure lateral and medial anterior condyle heights, anterior trochlear groove heights, and anterior condyle width, which were normalized by the anterior–posterior and medial–lateral dimensions of the knee, respectively. The shape of anterior condyle groove was also analyzed.ResultsThe mean lateral anterior condyle height, medial anterior condyle height and anterior condyle width of females were 6.6 ± 1.8 mm, 2.0 ± 2.3 mm, and 44.7 ± 4.2 mm, respectively. These data were significantly smaller (p < 0.05) than those of males (7.7 ± 1.8 mm, 2.9 ± 2.0 mm and 50.0 ± 3.4 mm). However, after normalizing by the femur size, the aspect ratios had no gender differences. Both the ranges of lateral and medial condyle of females were significantly smaller than those of males, and the geometry curve of anterior condyle was different between genders.ConclusionAlthough the gender differences in anterior femoral condyle sizes no longer existed after normalization with the femur size, the shape and the peak position of anterior condyle groove still have gender differences. The data may have important implications on the current debate of gender-specific TKAs.Clinical relevanceThis study provides a better understanding of gender differences in anterior femoral condyle geometry.     

3D打印技术制备β-磷酸三钙仿生骨支架在兔股骨髁部骨缺损修复中的应用

目的 探讨采用3D打印技术制备的β-磷酸三钙(β-TCP)仿生骨支架的形态结构特点及其相关生物性能,并观察其修复新西兰兔股骨髁部骨缺损的效果。方法 选取5～6月龄新西兰大白兔20只,随机分为支架组和空白组,每组10只;两组大白兔按造模术后采集标本的时间不同又分为两个亚组,每组5只。两组大白兔均于左侧股骨用环钻钻取直径约5 mm、长约10 mm的圆柱形松质骨块,建立股骨髁骨缺损模型。空白组截取的10个松质骨标本,使用微计算机断层扫描技术进行扫描,获得骨缺损标本的结构影像学数据,通过3D生物打印系统设计出相应的仿生骨支架模型,再以β-TCP作为打印材料,打印出20枚仿生骨支架。取10枚β-TCP支架测量高度、直径,电子显微镜下观察β-TCP支架孔道形态结构特点,测量大孔的直径和孔隙率,使用电子力学测试机测定β-TCP支架的弹性模量与抗压强度。空白组10只大白兔造模后不植入任何材料。支架组10只大白兔在造模后,将制备的10枚β-TCP支架植入骨缺损处。分别于术后第6、12周使用耳缘静脉推注空气方法处死空白组和支架组的各亚组大白兔,于骨缺损部位或植骨部位上下离断、截取长约10 mm骨段,制备切片,HE染色,观察骨组织生长情况;采用Lane-Sandhu组织学评分标准对骨组织修复情况进行评价。结果 使用3D生物打印技术制备的20枚圆柱体β-TCP支架,与松质骨标本结构形态相似。支架高度(9.97±0.08)mm、直径(5.09±0.07)mm,松质骨标本高度(9.96±0.39)mm、直径(5.01±0.22)mm,支架与松质骨标本比较差异均无统计学意义(P值均＞0.05)。扫描电镜观察到支架表面及内部呈均匀多孔状,孔径相互连通,大小相仿,孔隙分布较均匀,在大孔侧壁布满了微孔,外形多为近似圆形;其中大孔直径为(223.02±18.20)μm,孔隙率为74.02%±1.38%。松质骨标本大孔直径(227.02±31.20)μm,孔隙率为76.02%±3.29%,支架与松质骨标本比较差异均无统计学意义(P值均＞0.05)。使用电子力学测试机测定支架的抗压强度为(2.93±0.65)MPa,弹性模量为95～190 MPa。骨组织切片HE染色:术后第6周,支架组植骨处可见较成熟的骨组织,骨小梁和骨髓组织增多,新生骨正在逐渐覆盖植骨材料,周围可见少量成骨细胞,出现少量新生骨并向材料内长入;空白组的骨缺损处周围有少量类骨组织形成,大量成纤维细胞和脂肪组织生长,未见明显成骨细胞及骨小梁结构。术后12周,支架组植骨处出现成熟的骨小梁和骨髓组织,有编织骨形成,新生骨量较多,部分材料已被吸收降解,材料存留较少;空白组的骨缺损处见少量骨组织从缺损边缘向内长入,大部分被成纤维细胞和脂肪组织填充。Lane-Sandhu组织学评分,术后6周、12周支架组分别为(5.2±0.3)、(8.1±1.2)分,空白组分别为(1.3±0.5)、(4.5±0.6)分,支架组评分均大于空白组,差异有统计学意义(t=7.341、12.672, P值均＜0.05)。结论 3D生物打印技术制备的β-TCP仿生骨支架,与松质骨标本的骨组织解剖结构形态相似,且具有良好的生物力学性能,可以提供个体化的仿生骨支架,修复新西兰兔股骨髁部骨缺损的效果良好。     

基于MRI的成人正常膝关节软骨形态学测量

目的：了解正常膝关节软骨分布及股骨髁承重区的软骨厚度特点,为膝关节病变早期诊断和动态观察提供依据。方法：选取100名成人志愿者,男、女各50名,年龄20—30岁,平均25．3岁,膝关节均行MRI扫描。应用MIMICS软件对图像进行处理,在矢状位窗面上测量膝关节各部位软骨最大厚度。选择膝关节正常运动时的承重区,测量承重区域软骨的最大厚度并与其他区域进行比较。基于MRI图像行膝关节软骨三维重建,观察膝关节软骨的三维形态特征。结果：膝关节各部位的最大软骨厚度如下。胫骨外侧平台3．19mm,胫骨内侧平台3．07mm,股骨外侧髁2．93mm,股骨内侧髁3．19mm,股骨滑车软骨3．57mm,髌软骨3．75mm。不同性别与左右侧之间的软骨厚度差异无统计学意义（P〉0．05）。胫股关节承重区软骨厚度大于其他区域,有统计学差异（P〈0．05）。结论：成人正常膝关节各区域软骨厚度不同,胫股关节承重区软骨厚度大于非承重区域。基于MRI可以准确地测量膝关节各部软骨的厚度及重建膝关节软骨的三维形态。     

Morphometric study of the human fetal heart. I. Arterial segment

This study measured the dimensions of the great arteries of normal human fetal hearts at an early fetal stage (between 13-20 weeks post-fertilization) in 103 fetuses obtained by necropsy. Different segments of the aorta and the pulmonary artery were dissected and their external diameters measured under stereoscopic magnification. All segments showed linear growth during this period of fetal development. Ranges in median values of external diameters associated with the pulmonary artery were: 2.1-4.2 mm for the valve ring; 2.2-4.2 mm for the main pulmonary trunk; 1.2-2.5 mm for the right pulmonary artery; 0.9-2.18 mm for the left pulmonary artery; and 4.0-8.0 mm for the length of the main pulmonary trunk. Similarly, in the aorta, median diameters were: 2.1-4.2 mm for the ascending aorta; 1.92-3.8 mm for the aortic arch; 1.45-3.0 mm for the aortic isthmus; and 1.75 -3.35 mm for the descending aorta. The diameter of the ductus arteriosus ranged between 1.2-2.45 mm. The growth rates of the pulmonary artery and the aorta were similar. The diameter of the ascending aorta was found to be greater than that of the descending aorta and the right pulmonary artery was wider than the left pulmonary artery. In addition, the magnitude of growth in the various aortic segments was different and the ratios obtained between the aortic isthmus and the ascending and descending aortae, ranged between 0.66-0.93. This study provides important morphometric reference information concerning the dimensions and growth of the great arteries of the fetal heart and has clinical application in pediatric cardiac surgery and echocardiography.     

A simplified relationship between the femoral trochlea and the femoral condyle: A sagittal MRI analysis by an ellipse-fitting approach

We have introduced an ellipse-fitting approach to express the shapes of trochlea and condyle on magnetic resonance imaging (MRI) and to analyze their relationship. Fifty healthy right knees were sagittal-imaged by MRI at full extension. On the deepest trochlear groove slice, the articular surface was best-fitted by a circle. Based on the center of this circle, both the most prominent slices of the medial and lateral trochleae were best-fitted by ellipses. On the most distal slice of medial condyle, the articular surface was best-fitted by a horizontal ellipse. Based on the center of this ellipse, the lateral condyle was best-fitted by a rotational ellipse. The semimajor and semiminor axes of the trochlear ellipse and the condylar ellipse constituted a rectangle that represented the relationship between the trochlea and the condyle. The anteroposterior dimension (l) of this rectangle was 12.33 ± 1.41 mm, and the superoinferior dimension (w) was 7.21 ± 1.23 mm. The average tangent angle (θ) of the rectangle was 30.1° ± 2.6°. There were significant sex differences in l, w, and θ (all P ≤ 0.006), and all correlated significantly with the height of the subject (all P ≤ 0.001). The relationship between the femoral trochlea and the femoral condyle differed significantly between males and females, but this could have been a consequence of the significant correlation with subject height. Clin. Anat. 33:500–506, 2020. © 2019 Wiley Periodicals, Inc.     

Promontory of radius: a new anatomical description on the distal radius

Surgical treatment of distal radius fractures with palmar plates has gained popularity as the preferred approach to achieve anatomical fracture reposition. One hundred and thirty four radii of human cadavers were examined to elucidate the anatomy of the distal radius, especially the transition of the anterior into the lateral surface and a new term was given: promontory of radius. The promontory was located on the lateral surface between the changing of the convex to the concave curvature and the base of the styloid process. The anterior surface increased gradually from the ulnar notch to the lateral surface and formed the "base" of the promontory. The length of the promontory on the lateral surface measured 14-28 mm (mean 20.766 mm, SD 2.69 mm). The width of the promontory was found in between 10 and 27 mm (mean 13.857 mm, SD 2.14 mm). The width of the distal radius was 16-38 mm (mean 31.015 mm, SD 3.26 mm) and did not show any statistical correlation to the promontory. On the anterior surface the minimal width of promontory measured 4.9 mm, the maximal one 17.9 mm (mean 8.95 mm, SD 3.60). The height of the promontory on the anterior surface ranged in between 1.2 and 4.3 mm (mean 2.90 mm, SD 1.05 mm). The promontory of radius must be kept in mind to avoid any dorsal dislocation of the radial fragment often described as complication of intraarticular fractures. Based on this anatomical survey the data can be used for a new palmar radius plate designs.     

Optimal design of thread height and width on an immediately loaded cylinder implant: A finite element analysis

In this study, we used a finite element method to evaluate the maximum Von Mises stresses in jaw bones of immediately loaded implant with different thread heights and widths, and the maximum displacements in implant-abutment complex. The implant thread height ranged from 0.20 to 0.60 mm, and the thread width ranged from 0.10 to 0.40 mm. Compared to those in standard designed implants, the maximum Von Mises stresses in cortical and cancellous bones with axially loaded implants decreased by 18.85% and 47.46%, respectively, and by 16.38% and 63.46%, respectively in buccolingually loaded implants. The maximum displacement of implant-abutment complex loaded axially and buccolingually decreased by 13.78% and 6.97%, respectively. These results indicated that thread height played more important roles in affecting bone stresses and implant-abutment complex stability than thread width. Immediately loaded cylinder implants with thread height exceeding 0.44 mm and width ranging from 0.19 to 0.23 mm caused the lowest stresses to the type B/2 bone.     

兔股骨髁临界性骨缺损动物模型制备及临界骨缺损值

文题释义：临界性骨缺损：首先定义为自然状况下骨缺损不进行任何处理无法自愈的最短的骨缺损尺寸。随后考虑到观察实验动物完整的生命周期是非常困难的,将临界性骨缺损值定义为在实验期间物种不能自行愈合的最短骨缺损尺寸。 动物模型：是在医学研究中建立的模拟人类疾病表现的动物,骨组织工程中建立临床相关的测试动物模型来研究材料的生物相容性、降解、力学性能以及与宿主组织的相互作用,是体外实验和人体临床试验之间的关键一步。 背景：兔股骨远端骨缺损模型被研究者们广泛用于骨缺损替代骨组织工程材料的测试,但对于兔股骨髁圆柱形骨缺损模型的大小文献报道不一,直径分布在5-9 mm,深度8-12 mm,目前尚无统一的标准。 目的：建立兔股骨髁不同尺寸骨缺损模型,确定兔股骨髁临界性骨缺损尺寸。 方法：6月龄雄性新西兰白兔18只,随机分为3组,每组各6只,分别建立骨缺损模型,骨缺损直径依次为5,6,7 mm,深度均为10 mm,双侧手术,共计12侧。分别于术后第1天及术后第4,8,12周行CT扫描及三维重建,CT-Hedberg评分评价骨缺损愈合情况;于术后12周处死新西兰白兔,取出股骨髁缺损样本,通过大体观察和苏木精-伊红染色分析缺损区愈合情况。实验方案经徐州医科大学实验动物道德伦理委员会批准。 结果与结论：①术后所有兔均存活,术后12周大体观察示：直径5 mm组缺损由新生骨组织充填,股骨髁塑形良好,骨缺损基本完全修复;直径6 mm组、直径7 mm组骨缺损区可见明显凹陷,新生骨组织较少,骨缺损未修复;②CT图像示：术后第4,8周,直径5 mm组缺损区逐渐减小,断端桥接;直径6 mm、直径7 mm组缺损区仅周边有少量新生骨长入,缺损面积较前稍减小;术后第12周可见直径5 mm组皮质骨结构完整、连续,骨缺损基本完全修复;直径6 mm组骨缺损部分修复;直径7 mm组缺损未修复,仍可见明显缺损空腔存在;③CT-Hedberg评分显示,术后各时间点直径6 mm组评分显著低于直径5 mm组(P < 0.05);与直径7 mm组比较差异无显著性意义(P > 0.05);④组织学结果示：术后12周直径5 mm组缺损区出现排列不规则的骨小梁结构,并可见大量新生骨组织填充,其他2组在骨缺损周边可见部分新生骨小梁存在,但缺损区新生骨组织填充较少;⑤结果说明,在12周的实验观察期内,在缺损深度同为10 mm的条件下,直径>6 mm的股骨髁缺损未能自行愈合,而直径<6 mm的股骨髁缺损基本完全修复。此结果符合临界骨缺损的标准,故直径6 mm可作为兔股骨髁临界骨缺损值。 ORCID: 0000-0002-1257-965X(徐石庄) 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     

内蒙古地区枕骨髁及枕骨大孔应用解剖三维数字化测量

目的 利用三维重建测量枕骨髁(OC)及枕骨大孔(FM)解剖学结构,分析OC、FM形态学特征及相对位置关系,为颅颈交界区病变的影像学诊断及外科手术入路的选择提供解剖学参数.方法 选取60例正常者的头颅和上颈椎螺旋CT扫描图像,男、女各30例,年龄20～65(48.18±16.17)岁,将数据导入Syno.Via VB10...     

Development of sutureless vascular connecting system for easy implantation of small-caliber artificial grafts

A novel sutureless vascular connecting system, an assembly with a delivery rod, an introducing sheath, and a connecting device, was developed for easy implantation of small-caliber vascular grafts less than 2 mm in internal diameter. A microporous stainless tube (length 2 mm, external diameter 1.6 mm, wall thickness 65 µm, pore diameter 400 µm, pore-to-pore distance 500 µm) was designed to serve as a connecting device. The feasibility of the system was tested using two types of preliminary animal experiments. One animal model consisted of graft implantation into the rat abdominal aorta (1.5 mm in diameter). The connecting device was inserted into the proximal and distal ends of the aorta through the introducing sheath by pushing the delivery rod with the connecting device placed over it. Subsequently, the aortic segments were inserted into both ends of model grafts made of segmented polyurethane (1.8 mm in internal diameter) and were fixed with banding silk threads from the exterior. The procedure was completed within 20 min without requiring specialized microsurgery techniques. Blood leakage and obstruction did not occur. The second model consisted of an end-to-end anastomosis between rabbit common carotid arteries (2 mm in diameter), which was performed within several minutes of blood flow interruption. Scanning electron microscopy demonstrated that the luminal surface of the device was fully covered with endothelial cells (ECs) after 1 week as a result of transluminal ingrowth of native ECs through the micropores in the device. This endothelialization may prevent early thrombus-induced occlusion. This simple and “easy-to-learn” technique will promote the development of small-caliber arterial grafts, and furthermore, it may have potential for clinical application.     

Morphological Changes in the Mandible of Male Mice Associated With Aging and Biomechanical Stimulus

Degenerative changes in the temporomandibular joint (TMJ) associated with aging can affect mandibular shape and reduce growth potential when stimulated by functional appliance therapy. This study was designed to evaluate the morphological changes in the mandibles of male mice associated with aging and biomechanical stimulus. Every 3 days over the course of 1 month, the lower incisors were trimmed by 1 mm to induce mandibular advancement (MA) when the animal was feeding. The left mandibles of the 23 experimental and 27 control animals were subsequently dissected, and digital images were obtained to analyze nine linear/angular measurements. Because mandibular morphology depends on the maintenance of condylar cartilage, the surfaces of the condylar cartilage and the ascending ramus of the mandible were also analyzed by scanning electron microscopy (SEM). The linear measurements of the mandible showed changes according to age in the control group and a growth response in the mandibular condyle in 7‐ and 15‐month‐old mice after MA. Moreover, SEM analysis revealed depressions in the anterior region of the condylar cartilage and inclined vascular grooves in the ascending ramus in the 7‐ and 15‐month‐old experimental mice. Although the growth potential is reduced in mice after 6 months of age, the results showed that continuous growth of the mandible occurs after maturation, except in the condyle, and that biomechanical stimulus of the TMJ of male mice leads to condylar growth. These results suggest that mature and old individuals can favorably respond to maxillary functional orthopedic therapy. Anat Rec, 292:431–438, 2009. © 2009 Wiley‐Liss, Inc.     

Intra-operative navigation of knee kinematics and the influence of osteoarthritis

Intra-operative assessment of knee kinematics should optimise implantation of total knee arthroplasties. The purpose of this work was to validate the data delivered by an adapted navigation system in 10 healthy cadaver knees and to investigate the kinematics of 10 osteoarthritic (OA) knees in patients undergoing total knee replacement. The system displayed the magnitude of axial rotation, the position of the instantaneous centre of axial rotation and the displacements of the condyles. Successive cycles from full extension to 140° of flexion in the same knee produced a mean external rotation of 20° ± 10°, which was correlated to knee flexion (r=0.6 ± 0.2 in healthy knees, r=0.8 ± 0.2 in OA knees). The centre of axial rotation migrated posteriorly an average of 8.2mm in both groups. The posterior displacements were 4 mm ± 5 mm in healthy and 5 mm ± 6 mm in OA knees for the medial condyle, and 21 mm ± 9 mm in healthy and 21 mm ± 10 mm in OA knees for the lateral condyle. The medial condyle lifted off beyond 110° of flexion. Results in healthy knees were consistent with those reported in the current literature. The kinematics of healthy and of OA knees with an intact anterior cruciate ligament did not differ significantly.     

A convex lateral tibial plateau for knee replacement

Unicompartmental knee replacements have not performed as well in the lateral compartment as in the medial. This may be because the tibial components have flat or slightly concave surfaces which match the medial plateau but not the convex lateral plateau. The aim of this study was to find the optimal radius for a convex lateral tibial component. Twelve normal lateral tibial plateau were retrieved at knee replacement, and their surface contour in their mid sagittal plane was determined. The optimal circle was fitted and its radius measured. A series of different shaped tibial components were superimposed. From published information about the position of the femoral condyle relative to the tibia in different degrees of flexion, the flexion gap at these angles was determined. The average radius of the lateral tibial plateau was 40 mm. However, as the surface was polyradial it was not clear if this average radius would be optimal. In full flexion, a flat tibial plateau distracted the knee by 8 mm (p<0.001). A 75 mm radius spherical tibial plateau did not alter the knee kinematics significantly and gave rise to a change in joint distraction of 1.5 mm. Spherical tibial plateau of 50 mm and 25 mm radii significantly altered knee kinematics (p<0.001) and resulted in changes in distraction of 3 mm and 4 mm respectively. The optimal shape for a unicompartmental lateral tibial plateau is likely to be a spherical dome with radius of about 75 mm. The incorporation of this shape in the lateral side of a total knee replacement might improve its flexion.     

Radiographic evaluation of frontal talar edge configuration for osteochondral plug transplantation

For successful reconstruction of osteochondral lesions of the talus, the anatomic configuration of the talar edge must be respected. This study evaluated the radiographic configuration of the talar edge in the anterior‐posterior (AP) view by analyzing medial and lateral talar edge angles and radii in 81 patients with a true AP view and without ankle pathology. The mean lateral talar edge angle was 91.8°, and the mean medial talar edge angle was 110.0°. The medial frontal talar edge radius was 4.8 mm and the lateral 3.5 mm, respectively. No correlation between angle and radius was found. These results revealed a significant difference between the medial and the lateral talar edge configuration. This may be due to the three‐dimensional function of the human ankle joint. No study so far has addressed these differences radiologically. These differences should be addressed in the reconstruction of osteochondral lesions and be included in the preoperative planning. Clin. Anat. 22:261–266, 2009. © 2008 Wiley‐Liss, Inc.