基于MRI快速建立前交叉韧带三维数字化模型初步报道

目的　研究利用MRI二维图像快速建立前交叉韧带(ACL)三维数字化模型的方法,并评估模型的真实可靠程度。 方法　 选择 20 例临床诊断为ACL断裂患者的术前健侧MRI图像资料,导入自主开发的ACL快速分割技术软件（3D MIA ）进行图像分割,再以面绘制方式进行三维重建,建立膝关节及ACL三维数字化模型,测量模型的ACL长度、宽度、厚度及与人体三个解剖平面的角度,所得数据与前期解剖研究结果进行统计学的分析对比,评估模型的可靠程度。 结果 造模包括膝关节各骨性结构及前后交叉韧带,平均造模时间18 min,测量得到ACL长(39.80±1.86)mm、宽(5.80±1.83)mm、厚(9.96±1.26)mm;ACL与冠状面夹角(27.58±3.64)°、与矢状面夹角(39.82±4.01)°、与水平面夹角(22.27±4.23)°。与前期研究获得的相应数据对比,经独立样本t 检验,差异均无显著性意义(P>0.05)。 结论 利用自主开发的ACL分割技术及三维重建软件可以快速且较准确地建立健侧 ACL三维数字化模型,为计算机辅助ACL手术系统及实现ACL临床仿真个体化解剖重建提供了参考基础。     

膝关节前交叉韧带的解剖学观测

在50侧尸体膝关节上,对前交叉韧带的股骨附着区、胫骨附着区、长度、方向和宽度进行了形态学测量,提供了详细的数据。股骨附着区呈椭圆形,胫骨附着区似三角形。前交叉韧带本身呈50°扭曲状态,随屈膝程度的增加,其扭曲程度也增加,这种变化的幅度,在韧带表面的纤维较中心部位者为大,这与前交叉韧带两附着区的形态有密切关系,尤其是股骨附着区。     

30°屈曲体位膝关节MRI对显示前交叉韧带和评价韧带断裂的应用价值

目的探讨在膝关节MRI检查中采取30°屈曲体位对前交叉韧带(ACL)显示及其断裂评价方面的价值。方法选择患膝外伤并行关节镜检查的70例患者,其中男性38例,女性32例;年龄24～56岁,平均年龄35.85岁。指导患者分别采取17°与30°屈曲体位膝关节MRI检查,后由2名影像学医师进行双盲原则下阅片,分别对ACL全长、双束结构、断裂点与残端情况进行评级。基于关节镜检查金标准,统计膝关节MRI不同体位下的疾病诊断准确度、特异度与灵敏度。结果经关节镜检查,确诊ACL断裂者41例,ACL正常者29例;17°屈曲体位MRI检查的准确度为91.43%,特异度为86.21%,灵敏度为95.12%;30°屈曲体位MRI检查的准确度、特异度和灵敏度均为100.00%;30°屈曲体位MRI检查的ACL全长成像优良率(95.71%)高于17°屈曲体位(80.00%),断裂点与残端成像优良率(92.68%)高于17°微屈体位(73.17%),差异有显著统计学意义(P=0.001 <0.01);两组双束结构成像优良率比较,差异无统计学意义(82.86%vs80.00%,P> 0.05)。结论 30...     

膝关节前交叉韧带的损伤及修复

本文就膝关节前交叉韧带附着部位、运动状态及其损伤后检查等作一综述。 L achmann试验对前交叉韧带损伤诊断有重要临床诊断价值。利用自身材料 (如髌腱、股薄肌腱、半腱肌肌腱 )转移重建前交叉韧带 ,手术时间应在伤后 4～ 8周内进行 ,并提出以这些组织结构修复前交叉韧带出现的弊端 ,以及以髂胫束作为替代物的可能性。     

膝关节前交叉韧带重建兔模型的建立

背景：传统前交叉韧带重建造模腱骨界面愈合缓慢,造模时间较长。   目的：通过在腱骨界面注入以纤维蛋白胶为载体的重组人骨形态发生蛋白2复合物,建立造模周期更短、更完善的兔膝关节前交叉韧带重建动物模型。 方法：取成年新西兰兔同侧半腱肌肌腱作为自体移植材料,建立双侧前交叉韧带重建动物模型,建模后随机分为模型组、纤维蛋白胶组,空白对照组和正常组。模型组在移植腱骨隧道界面注射填充以纤维蛋白胶作为载体的重组人骨形态发生蛋白2,纤维蛋白胶组在重建术后腱骨界面仅填充纤维蛋白胶,空白对照组在重建术后腱骨界面不作任何填充,正常组则不予手术,保留正常的前交叉韧带。各组分别于术后第4和8周取材,进行生物力学检测。 结果与结论：模型组最大载荷和刚度在术后4和8周与纤维蛋白胶组和空白对照组相比均增强(P < 0.01)。由此可见,实验成功建立了双侧前交叉韧带重建动物模型,以纤维蛋白胶作为载体的重组人骨形态发生蛋白2可以在术后早期提高腱骨界面的最大载荷和刚度,促进了腱骨界面的愈合,缩短了重建动物模型的实验周期。     

膝关节前交叉韧带与后交叉韧带粘弹性实验研究

研究了10具新鲜成人尸体膝关节前交叉韧带和后交叉韧带的拉伸力学性质和粘弹性力学性质,对前交叉韧带和后交叉韧带进行单向拉伸实验,得出了破坏载荷,强度极限、最大应变、伸长比、弹性模量.对前交叉韧带和后交叉韧带进行应力松弛,蠕变实验,得出了应力松弛、蠕变实验数据和曲线.对实验数据进行归一化处理,得出了归一化应力松弛函数,蠕变函数,以回归分析的方法处理实验数据,得出了回归系数,很好的拟合了实验曲线.实验结果表明:前交叉韧带的拉伸强度极限、最大应变等大于后交叉韧带,后交叉韧带7200s应力松弛、蠕变量小于前交叉韧带.     

人工韧带重建前交叉韧带的膝关节功能评价

目的：探讨韧带增强重建系统( LARS)人工韧带重建前交叉韧带( ACL)手术的临床效果。方法采用随机数字表法将我院2011年9月至2013年5月收治的60例ACL损伤患者分为LARS组和自体腘肌腱( ST/G组)组,各30例,比较2组患者治疗前与治疗后3、6、9、18个月的Lysholm评分、主客观IKDC评分、末次随访的临床疗效及骨隧道扩大情况的差异。结果LARS组扶拐下地时间、弃拐行走时间、恢复运动时间3项指标均显著短于ST/G组(P<0.05)。与术前相比,2组Lysholm评分及IKDC评分术后3、6、9、18个月均显著好转(P<0.05);术前2组Lysholm评分及IKDC评分比较差异不显著(P>0.05);术后3、6、9个月LARS组Lysholm评分及IKDC评分显著优于ST/G组,至术后18个月2组患者的Lysholm评分及IKDC评分差异不显著(P>0.05)。末次随访时,LARS组疗效分布显著优于 ST/G 组(P <0.05);LARS 组优良率93.33%高于 ST/G 组的76.67%,但差异不显著(P>0.05)。 LARS组共6例患者出现骨隧道扩大,ST/G组14例患者出现骨隧道扩大,ST/G组出现骨隧道扩大率显著高于LARS组(P<0.05)。结论韧带增强重建系统人工韧带重建前交叉韧带较自体腘肌腱重建能够显著加快患者的恢复,同时提高术后疗效及降低术后骨隧道扩大的发生率。     

前交叉韧带的应用解剖

在100侧成人尸体的膝部,对前交叉韧带进行了解剖学研究.多束性前交叉韧带分为前内束和后外束,其神经血管束沿束间的疏松结缔组织分布于其中,其主要血供来自膝中动脉支,在韧带周围形成血管滑膜鞘.保护和利用此鞘,以利受损韧带在修复时愈合。     

膝关节前交叉韧带修复的组织工程研究进展

本文介绍了前交叉韧带组织工程(即利用组织工程的方法重建具有生物性能的韧带,恢复损伤韧带的生理功能)的研究现状,展望了其发展前景,并分析了该领域有待解决的关键问题,重点论述了前交叉韧带组织工程中种子细胞、生物支架、材料表面修饰、生长因子等的选择和应用。     

膝关节前交叉韧带与内侧副韧带粘弹性实验研究

目的　研究了新鲜成人尸体膝关节前交叉韧带和内侧副韧带的粘弹性力学性质，为临床提供生物力学参数依据。方法　对前交叉韧带和内侧副韧带进行应力松弛，蠕变实验。结果　对实验数据进行归一化处理，得出了归一化应力松弛函数，蠕变函数，以回归分析的方法处理实验数据，得出了回归系数和拟合曲线。结论　内侧副韧带7200s应力松弛、蠕变量小于前交叉韧带。对实验结果进行分析讨论。     

Inter-observer agreement in the identification of the two bundles of the anterior cruciate ligament using magnetic resonance imaging

Background  Magnetic resonance imaging has become the method of choice to diagnose meniscal and ligament lesions of the knee. New approaches to the surgical treatment of partial anterior cruciate ligament tears led us to try to distinguish the two bundles of that ligament with MRI and to evaluate inter-observer agreement in different viewing planes. Methods  Images of 50 right and 50 left ligament-intact knees were examined in the coronal and axial viewing planes. Each sequence was independently read by a radiologist and a medical student to note, in each viewing plane, the number of images in which the two-bundle structure of the ligament was clearly seen. Cohen’s Kappa coefficients were used to determine inter-observer agreements. Results  The percentage of sequences in which the two bundles were distinguished by the radiologist and the student on one image at least were 82 versus 73% in the coronal plane and 90 versus 93% in the axial plane, respectively. The average number of successive images with clear bundles was higher in the axial (2.7 vs. 1.7) than in the coronal plane (2.2 vs. 1). There was a poor inter-observer agreement in the coronal plane (k = 0.176) but an intermediate agreement in the axial plane (k = 0.385 or 0.522 depending on number pooling). Conclusions  The axial viewing plane seems more favourable to distinguish the two bundles of the anterior cruciate ligament with the best possible reproducibility. An oblique-axial plane is deemed to insure a clearer diagnosis of partial tears.     

Three-dimensional engineered bone-ligament-bone constructs for anterior cruciate ligament replacement

The anterior cruciate ligament (ACL), a major stabilizer of the knee, is commonly injured. Because of its intrinsic poor healing ability, a torn ACL is usually reconstructed by a graft. We developed a multi-phasic, or bone-ligament-bone, tissue-engineered construct for ACL grafts using bone marrow stromal cells and sheep as a model system. After 6 months in vivo, the constructs increased in cross section and exhibited a well-organized microstructure, native bone integration, a functional enthesis, vascularization, innervation, increased collagen content, and structural alignment. The constructs increased in stiffness to 52% of the tangent modulus and 95% of the geometric stiffness of native ACL. The viscoelastic response of the explants was virtually indistinguishable from that of adult ACL. These results suggest that our constructs after implantation can obtain physiologically relevant structural and functional characteristics comparable to those of adult ACL. They present a viable option for ACL replacement.     

MR imaging of acute anterior cruciate ligament injuries

MRI of the knee has become an indispensable clinical tool in the management of chronic knee conditions. MRI for acute knee injuries is less well established but is becoming increasingly prevalent. MRI in acute ACL injuries is particularly useful for identifying associated injuries that will influence the early management of the patient. The aim of this paper is to describe the MRI findings of acute ACL tears, their commonly associated, and less common but serious associated injuries. Where available, the evidence for the sensitivity and specificity of these MRI features is presented. The contribution of these MRI findings to the management of the patient is discussed.     

The accuracy of magnetic resonance imaging in diagnosing chronic posterior cruciate ligament injury

Magnetic resonance imaging (MRI) is widely believed to be highly accurate in diagnosing injuries of the posterior cruciate ligament (PCL). The aim of this study was to determine the accuracy of MRI in diagnosing chronic PCL injury. MRI was performed on 10 knees with a clinical and arthroscopic diagnosis of a PCL injury sustained at least 6 months previously. Seven experienced musculoskeletal radiologists subsequently reviewed the scans. Their accuracy in diagnosing a PCL injury was 57% (40-80%). Thus, although MRI may be reliable in diagnosing acute PCL injury, MRI is not so reliable in evaluating chronic injuries. We postulate that, in the case of a chronic PCL injury, healing in continuity may occur, producing an intact but lax ligament. As demonstrated by our study, MRI may then be less accurate. This should be borne in mind when assessing the MRI scans of a suspected chronic PCL injury.     

Magnetic resonance imaging of the posterior cruciate ligament in flexion

Background

Posterior cruciate ligament (PCL) injuries of the knee are common and sometimes difficult to diagnose. Magnetic resonance imaging (MRI), performed using standard orthogonal plane views, is the investigation of choice. It can be particularly difficult to differentiate acute partial and complete tears and identify elongation of chronic healed tears. The aim of the paper is to describe a new method of positioning the patient with the knee flexed at 90°, allowing the PCL to be visualised in a position of greatest length and tension which may assist in differentiating and identifying these injuries.

Comparison of anterior cruciate ligament volume after anatomic double-bundle anterior cruciate ligament reconstruction

Backgroud

To determine whether anatomic double-bundle anterior cruciate ligament reconstruction (DB-ACLR) can restore the native ACL volume, and whether the volume change after reconstruction affects clinical outcomes and re-rupture rates following the contemporary techniques.

膝关节前交叉韧带损伤的弥散张量成像观测

目的　为膝关节前交叉韧带损伤分度提供新的影像诊断依据。 方法　选取膝关节弥散张量成像扫描检查正常者100例和单侧前交叉韧带撕裂伤者100例,后者按照损伤程度分为Ⅰ~Ⅳ级,在工作站划分前交叉韧带损伤处及正常组相应部位感兴趣区,测量各向异性分数（fractional anisotropy,FA）和表观弥散系数（apparent diffusion coefficient,ADC）,生成纤维示踪图像。 结果　前交叉韧带损伤处与正常组相应部位的FA和ADC差异有统计学意义,损伤处的FA低于正常组,ADC高于正常组。前交叉韧带Ⅰ级、Ⅱ级、Ⅲ级、Ⅳ级损伤处的FA和ADC差异有统计学意义,FA随损伤程度增高而逐渐降低,与损伤程度呈负相关;ADC则逐渐增高,与损伤程度呈正相关。FA和ADC、纤维示踪成像及MRI诊断前交叉韧带损伤程度分级的灵敏度、特异度、准确度、阳性预测值及阴性预测值差异均有统计学意义,从高到低均依次为纤维示踪成像、FA和ADC、MRI。 结论　膝关节前交叉韧带损伤处的FA和ADC与损伤程度密切相关,纤维示踪成像可以提高损伤程度分级的准确率,弥散张量成像可以为前交叉韧带损伤分级提供更准确的影像诊断依据。