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.     

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。     

前交叉韧带及其替代物粘弹性性质的实验研究

本研究采用新鲜成人膝关节标本，对前交叉韧带及其转换替代物（髌韧带、髂胫束）进行系统的粘弹性力学性质的实验研究，通过粘弹性力学模型的建立，推导前交叉韧带及髌韧带、髂胫束的本构方程，对韧带的蠕变和松驰现象进行系统的分析。结果表明，韧带的损伤与韧带的生理力学性质有关，髌韧带的粘弹性性质更接近前交叉韧带，关节内髌韧带转换比髂胫束为佳。     

前交叉韧带胫骨棘止点的形态学特征及其生物力学特性研究

目的:研究前交叉韧带及其胫骨棘止点处的形态特征及其抗拉伸性能,为前交叉韧带胫骨棘撕脱骨折的临床治疗提供解剖和生物力学依据。方法:取正常成人新鲜的膝关节标本16例,游离出前交叉韧带,对其胫骨棘止点处的厚度、宽度及其在胫骨棘止点处的分布特点等进行观察。新鲜的标本通过MTS-858材料试验机测试前交叉韧带附着端的抗拉伸性能。结果:前交叉韧带呈水平位附着于胫骨棘及其周围的骨面,其断面近似于三角形,底朝前,尖向后方。部分纤维附着于外侧半月板的前、后角及内侧半月板前方的骨面。附着端横径为(11.3±1.4)mm、前后长径为(17.6±2.6)mm、周径为(49.2±6.1)mm、前缘距胫骨平台前缘为(11.5±2.6)mm、后缘距后交叉韧带胫骨附着区的前缘为(14.1±1.7)mm、计算附着面积为(96.6±8.3)mm2。前交叉韧带的最大载荷为(2546±89)N,最大变形量为(4.3±0.5)mm。结论:前交叉韧带的纤维分布及其胫骨棘止点处的形态特征以及生物力学特性与临床上撕脱骨折的治疗有很大的关联性。     

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。     

拇指掌指关节侧副韧带粘弹性的实验研究

研究正常国人新鲜尸体的拇指掌指关节侧副韧带的粘弹性力学性质,为临床提供生物力学参数。对拇指掌指关节侧副韧带进行拉伸应力松弛、蠕变实验。得出了拇指掌指关节侧副韧带的应力松弛、蠕变数据。对实验数据进行归一化处理,得出了归一化应力松弛函数、蠕变函数及曲线。以回归分析的方法处理实验数据,得出了回归系数。表明拇指掌指关节侧副韧带为粘弹性生物材料。     

正常国人腰间盘纤维软骨粘弹性实验研究

研究了正常国人急性外伤致死的成人新鲜尸体10个腰间盘L3-4、14-5纤维软骨的力学性质。以一维拉伸的方法得出了L3-4、L4-5腰间盘纤维软骨的破坏载荷、伸长比、Lagrange张应力、Lagrange张应变等数据。以多项式，用回归分析方法得出椎间盘L3-4、L4-5纤维软骨的应力-应变关系表达式及应力-应变曲线。还对椎间盘L3-4、L4-5纤维软骨进行拉伸应力松弛、蠕变实验。得出了椎间盘L3-4、L4-5纤维软骨的归一化应力松弛函数、蠕变函数G(t)、J(t)表达式。以冯元桢教授的软组织大变形准线性理论，构建了L3-4、L4-5椎间盘纤维软骨的松弛函数K(λ，t)=G(t)T^(e)(λ)的表达式，对实验结果进行分析讨论。     

兔前交叉韧带生物力学的研究

作者对20例家兔前交叉韧带的形态学进行了研究,并应用INSTRON-1121型材料试验机对股骨-前交叉韧带-胫骨复合体的生物力学特性进行了测试.结果表明:兔股骨-前交叉韧带-胫骨复合体的生物力学特性与人及恒河猴前交叉韧带的生物力学特性基本一致.作者还对前交叉韧带的断裂力学进行了分析.     

前交叉韧带重建术后短期内移植体黏性变化

目的 研究前交叉韧带重建(anterior cruciate ligament reconstruction, ACLR)术后短时间内移植体黏性的变化规律。方法 选择6只雄性新西兰兔,以跟腱为移植体制作单侧膝关节ACLR动物模型。ACLR术后15 d将实验兔安乐死,取出移植体、健康的前交叉韧带(anterior cruciate ligament, ACL)和跟腱。测量移植体的截面积,分别进行0.1、1 MPa平衡条件的蠕变实验,并计算黏性系数,总结移植体的黏性变化规律,与健康ACL进行对比。结果 移植体的截面积在手术后15 d内缓慢上升。ACL与移植体的黏性呈非线性变化。在不同应力下,黏性系数有较大差异。移植体黏性系数随ACLR术后时间呈下降趋势,但在低应力下更明显。结论 本文建议,ACLR术后早期康复过程中,应使用助行器,降低步频,并避免踢、踹等对关节冲击的运动。     

Ultrastructural and Morphological Characteristics of Human Anterior Cruciate Ligament and Hamstring Tendons

Hamstring tendons are a commonly used substitute for anterior cruciate ligament (ACL) reconstruction. Ligaments and tendons are similar in composition but the ACL is more complex than hamstring tendons in function and gross morphology, which are highly dependent on its structure and ultrastructure. The purpose of this study was to compare the morphology and ultrastructure of normal human ACL and hamstring tendons, including the cell type and arrangement, expression level of proteoglycans, diameter, and density of collagen fibrils. Twenty semitendinosus or gracilis tendons and 20 ACL specimens were harvested from patients with ACL rupture or osteoarthritis undergoing routine total knee arthroplasty. The specimens were examined histologically and the ultrastructure was observed using scanning and transmission electron microscopy. Semitendinosus and gracilis tendons showed a homogeneous arrangement of collagen fibers and cell type. They had lower fibril density and more widely distributed fibril diameters. In the ACL, there was a more complex arrangement of collagen fibers, distribution of proteoglycans and different cell types. Electronic microscopy demonstrated a combination of parallel, helical and nonlinear networks of ACL fibrils, and fibril diameters were smaller and more nonuniform. This study compared the anatomy of normal human ACL and hamstring tendons, which may provide a standard for evaluating hamstring tendons grafts after ACL reconstruction and may facilitate the application of hamstring tendons in clinical applications. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.     

Functional Adaptation of the Fibrocartilage and Bony Trabeculae at the Attachment Sites of the Anterior Cruciate Ligament

The direct insertion of an enthesis is composed of uncalcified fibrocartilage (FC) and calcified FC, believed to function as buffers for multidirectional forces applied to the ligament. This study was performed to investigate the relationship between the FC thickness and bony trabecular orientation of the anterior cruciate ligament (ACL) on both the femoral and tibial sides. Six cadavers were examined (age at death: 73–92 years). Both femoral and tibial insertions of the ACL were harvested and used to make 0.5 mm interval semi-serial sections. Microdigital images were taken and used to measure the maximum thickness of both the uncalcified FC and Calcified FC. Two-dimensional discrete Fourier analysis was also performed to determine the orientation angle and orientation intensity of bony trabeculae directly under the FC. The mean thicknesses of the uncalcified FC at the femoral and tibial insertions were 0.98 mm and 0.49 mm, respectively. The mean thicknesses of the calcified FC were 0.47 mm and 0.38 mm, respectively. There was a significant difference in the uncalcified FC thickness, but not in the calcified FC thickness. The bony trabeculae showed a prominent orientation parallel to the ACL fiber on both sides, but it was more intense on the tibial side than on the femoral side. The trabecular orientation was prominent in the proximal-posterior part of the femoral side and in the anteromedial part of the tibial side, suggesting that mechanical stress is greater in these parts. The dominant bony trabecular angle was 69.0° on the femoral side and 59.8° on the tibial side when the tidemark was set at 0°. These findings suggest that the femoral side receives multidirectional stresses, while relatively unidirectional stress is loaded on the tibial side. Furthermore, stress is considered to be greater in the proximal-posterior part of the femoral insertion and in the anteromedial part of the tibial insertion. At the time of ACL reconstruction, attention should be paid to assign a robust portion of the graft to the posterior part of the femoral insertion and anteromedial part of the tibial insertion. Clin. Anat., 33:988–996, 2020. © 2019 Wiley Periodicals, Inc.     

前交叉韧带重建术后膝关节运动分析研究进展

膝关节前交叉韧带损伤是临床常见的严重影响膝关节稳定性的运动性损伤。尽管前交叉韧带重建(anterior cruciate ligament reconstruction,ACLR)可以修复韧带结构,但却无法恢复膝关节正常的运动学与动力学。近年来,利用运动分析评估ACLR术后疗效是运动医学及康复医学领域的研究热点。目前运动分析主要应用于ACLR术后疗效评价、个性化康复方案制定,也是探讨ACLR术后继发性损伤和早发性骨性关节炎潜在危险因素的科学客观工具。未来ACLR术后的运动分析更多关注于优化手术方案和康复治疗方案。回顾近10年ACLR术后膝关节运动分析的观察性研究和随机临床试验,介绍光学运动捕捉和双平面透视追踪在ACLR术后运动分析中的应用进展。临床研究表明,无论选择何种移植物和术式重建前交叉韧带,术后膝关节在功能任务中仍表现出异常的运动学特征,但术后膝关节生物力学的改变与早发性膝关节骨性关节炎的关系仍不清楚。恢复膝关节的旋转稳定性是临床ACLR手术最大的挑战之一。未来研究应通过合理的研究设计与长期随访,探讨ACLR对膝关节生物力学机制的影响,帮助临床医生和物理治疗师制定更有效的干预措施。     

A Functional Comparison of Animal Anterior Cruciate Ligament Models to the Human Anterior Cruciate Ligament

Many investigators have used animal models to clarify the role of the human anterior cruciate ligament (ACL). Because none of these models are anatomically and biomechanically identical to the human ACL, there exists a need for an objective comparison of these models. To do this, we used a universal force-moment sensor to measure and compare the in situ forces, including magnitude and direction, of the ACL and the anteromedial (AM) and posterolateral (PL) bundles of human, pig, goat, and sheep knees. An Instron was used to apply 50 and 100 N anterior tibial loads at 90° of knee flexion, while a universal force-moment sensor was used to measure the forces applied by the ACL to the tibia, the in situ force of the ACL. We found significant differences between the magnitude of force experienced by the goat and sheep ACL and AM and PL bundles when compared with the human ACL and AM and PL bundles. Also, the direction of the in situ force in the ACL and AM bundles of the goat and sheep were different from the human. The pig knee differed from the human only in the magnitude and direction of the in situ force in the PL bundle in response under anterior tibial loading. A tally of the significant differences between the animal models and the human knees indicates that goat and sheep knees may have limitations in modeling the human ACL, while the pig knee may be the preferred model for experimental studies.     

Anatomical Variability of Intercondylar Fossa Geometry in Patients Diagnosed with Primary Anterior Cruciate Ligament Rupture

The aims of this study were to (1) describe the three-dimensional characteristics and sources of anatomical variability in the geometry of the intercondylar fossa (“notch”) in an anterior cruciate ligament (ACL)-injured sample and (2) assess the relationship between patient factors and anatomical variability of the fossa in the context of impingement risk. A retrospective analysis of preoperative magnetic resonance imaging (MRI) for 49 patients with ACL rupture was performed. Scans were examined in the axial plane using an online picture archiving and communication system (PACS) viewer and fossa width and angle assessed at multiple slices, as well as anteroposterior depth, fossa height, and calculated total volume. Principal component analysis was performed to prioritize the sources of variability. A multivariate linear regression was performed to assess relationships between different patient factors, controlling for imaging parameters and principal component loadings. Geometric properties were normally distributed for all but fossa volume, height, and distal angle. Three principal components (PCs) were identified explaining 80% of total variance, shape (PC1), size in the coronal plane (PC2), and size in the sagittal plane (PC3). Patient factors were significantly (P < 0.05) related to PC loadings; however, a substantial amount of variance in each model remained unexplained. Intercondylar fossa characteristics vary considerably within ACL-injury patients with shape and size in coronal and axial planes, explaining most of the variance. Although patient factors are associated with anatomical characteristics, further work is required to identify the correct combination of factors accurately predicting geometry of the fossa for planning ACL reconstruction. Clin. Anat. 33:610–618, 2020. © 2019 Wiley Periodicals, Inc.     

人颈椎后纵韧带黏弹性实验研究

研究了正常国人8具新鲜尸体颈椎后纵韧带C1-C4、C4-T1的黏弹性力学性质.对C1-C4、C4-T1段后纵韧带进行拉伸应力松弛、蠕变实验.得出了C1-C4、C4-T1后纵韧带的应力松弛、蠕变数据和曲线.对应力松弛、蠕变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及曲线.对实验数据进行回归分析,得出了回归系数.还对后纵韧带C1-C4段、C4-T1段试样进行单向拉伸实验,得出了后纵韧带的拉伸破坏载荷、伸长比、拉应力、拉应变等,对应力应变数据以多项式,用最小二乘法进行拟合,得出其应力应变关系公式及曲线.构建了后纵韧带的松弛函数K(λ、t)=G(t)T(e)(λ)表达式,对实验结果进行分析讨论.     

Comparative Study on Anterior Cruciate Ligament Reconstruction: Determination of Isometric Points with and Without Navigation

OBJECTIVES:

To compare the accuracy of tunnel placement and graft isometry for anterior cruciate ligament reconstruction performed using a computer-assisted navigation system (Orthopilot) and using traditional instruments.

METHODS:

The anterior cruciate ligament was removed intact from 36 pairs of human cadaver knees. From each pair, one knee was randomized to Group 1 (conventional) and the other to Group 2 (Orthopilot). An inelastic suture was then passed through the central points of the tibial and femoral tunnels. Neither of the tunnels was drilled. All knees were then dissected, and six parameters were obtained: distances from the tibial tunnel center to the 1) posterior cruciate ligament, 2) anterior horn of the lateral meniscus and 3) medial tibial spine; 4) distance from the femoral tunnel center to the posterior femoral cortex; 5) femoral tunnel coronal angle; and 6) variation of the distance from the femoral to the tibial tunnel with the knee extended and at 90 degrees of flexion.

RESULTS:

The variation of the distance from the femoral to the tibial tunnel during flexion and extension was smaller in the Orthopilot group (better isometry) compared to the conventional group. There were no statistical differences in any other parameters between the groups, and all tunnels were considered to be in satisfactory positions.

DISCUSSION:

The results obtained for anterior cruciate ligament reconstruction depend on precise isometric point positioning, and a navigation system is a precision tool that can assist surgeons in tunnel positioning.

CONCLUSION:

No differences in tunnel position were observed between the groups. Nonetheless, better isometry was achieved in the Orthopilot group than with conventional instruments.     

非预期条件下前交叉韧带重建术后运动员侧切动作下肢运动生物力学特征

目的 量化非预期条件下前交叉韧带重建(anterior cruciate ligament reconstruction, ACLR)术后运动员侧切动作中膝关节生物力学特征,探讨运动员前交叉韧带(anterior cruciate ligament, ACL)损伤潜在风险。 方法 应用红外运动捕捉系统和三维测力台同步采集 30 名 ACLR 男性运动员在预期和非预期条件下侧切动作中健侧、患侧下肢运动学和动力学数据。 应用双因素方差分析对关节角度、关节力矩、地面反作用力( ground reaction force, GRF)等测试指标进行统计分析。 结果 患侧肢体的膝关节屈曲角度、外翻力矩和屈曲力矩显著低于健侧肢体,内旋力矩和胫骨前剪切力显著高于健侧肢体。 与预期条件相比,非预期条件下膝关节屈曲角度、内旋力矩、胫骨前剪切力显著增加。 患侧肢体膝关节外旋角度在预期和非预期条件下均显著高于健侧,非预期条件下健侧肢体侧向 GRF 和前后 GRF 显著小于预期条件,患侧肢体侧向 GRF 显著高于预期条件。 结论 ACLR 运动员进行侧切动作时,相比于健侧,患侧表现出较小的膝关节屈曲角度,较大的膝关节内旋力矩和胫骨前剪切力的生物力学特征,可能存在较大的 ACL 潜在损伤风险;在非预期条件下,ACLR 运动员双侧下肢均表现出膝关节内旋力矩增大,侧向 GRF 增大和胫骨前剪切力增大的生物力学特征,提示 ACL 潜在损伤风险不仅限于患侧,健侧下肢也应加强侧切动作中 ACL 损伤预防。     

视觉因素对前交叉韧带重建患者足底压力中心的影响

目的 分析患者前交叉韧带重建(anterior cruciate ligament reconstruction, ACLR)术后早期与术后 1 年在视觉因素影响下足底压力中心面积(center of pressure area, COPA)和压力中心速度(center of pressure speed, COPS)等参数的变化。 方法 纳入 ACLR 患者 17 例,于术后早期和术后 1 年测试足底 COPA 和 COPS 等数据;匹配 17 例健康受试者作为对照组。 进行睁、闭眼不同视觉状态站立平衡测试,对各测量状态进行相关性分析。 结果 双足站立测试时,短期组 COPA 和 COPS 在睁眼和闭眼对比均有统计学差异(P<0. 05);长期组 COPS 睁眼和闭眼对比有统计学差异(P<0. 001)。 健侧站立时,各组间差异具有统计学意义(P<0. 05),伤侧站立时各组间差异无统计学意义(P>0. 05)。 健侧站立睁眼条件下,长期组 COPA 高于短期组和对照组,对照组 COPS 低于短期组和长期组(P<0. 01)。 健侧站立闭眼条件下,对照组 COPA 低于短期组和长期组,对照组 COPS 低于长期组(P<0. 01)。 双足睁眼与双足闭眼之间、双足睁眼与伤侧睁眼之间、健侧睁眼和伤侧睁眼之间、健侧闭眼和伤侧闭眼之间在 COPA 和COPS 上均呈正相关。 结论 通过对 ACLR 患者站立位压力中心相关数据的分析,发现视觉对姿势稳定控制有重要影响。 术后 1 年患者双足和单足站立时对比正常人稳定性波动较大,提示在临床上要加强术后长期训练以巩固康复效果,并对开展长期评估和制定精准训练计划具有一定的指导作用,以防止术后长时间功能退化和降低再次损伤的风险。