The importance of ligaments in providing joint stability and the incidence of injuries, dictates a need to increase their structural and mechanical properties understanding. Additionally, one of the challenges in the ...The importance of ligaments in providing joint stability and the incidence of injuries, dictates a need to increase their structural and mechanical properties understanding. Additionally, one of the challenges in the orthopedic industry is to design TKA （total knee arthroplasty） aiming to be soft-tissues friendly. This requires a priori knowledge of physiological knee function, in which the passive stability is achieved and guaranteed by the complex envelope of soft tissues around the joint. Therefore, the knowledge of the mechanical behavior of knee ligaments is fundamental. For this reason, our study aims to define and apply in a pilot study, an ad-hoc methodology to mechanically characterize ligaments of native human knees. The cruciate and collateral ligaments from a fresh frozen cadaver leg were accurately harvested. Each ligament was independently tested during a tensile test at different strain rates, simulating different deformation speeds during gait. Moreover, additional tensile tests until failure were also performed. Axial force and deformation were continuously recorded during each test. Results show that each ligament exhibited own typical non-linear, speed-related behavior. High repeatability in the results is observed among the different repeated tests confirming the robustness of the used methodology. This information will be helpful for clinicians, engineers and researchers to improve the biomechanical knowledge about knee, to develop better implants and to be able to improve the currently available numerical models of the human knee.展开更多
AIM To examine the normal morphology of the epiligament tissue of the knee medial collateral ligament(MCL) in humans. METHODS Several samples of the mid-substance of the MCL of the knee joint from 7 fresh human cadave...AIM To examine the normal morphology of the epiligament tissue of the knee medial collateral ligament(MCL) in humans. METHODS Several samples of the mid-substance of the MCL of the knee joint from 7 fresh human cadavers(3 females and 4 males) were taken. Examination of the epiligament tissue was conducted by light microscopy and photomicrography on semi-thin sections of formalin fixed paraffin-embedded blocks that were routinely stained with haematoxylin and eosin, Mallory stain and Van Gieson's stain. Electron microscopy of the epiligament tissue was performed on ultra-thin sections incubated in 1% osmium tetroxide and contrasted with 2.5% uranyl acetate, lead nitrate, and sodium citrate.RESULTS The current light microscopic study demonstrated that the epiligament of the MCL consisted of fibroblasts, fibrocytes, adipocytes, neuro-vascular bundles and numerous multidirectional collagen fibers. In contrast, the ligament body was poorly vascularised, composed of hypo-cellular fascicles which were formed of longitudinal groups of collagen fibers. Moreover, most of the vessels of the epiligament-ligament complex were situated in the epiligament tissue. The electron microscopic study revealed fibroblasts with various shapes in the epiligament substance. All of them had the ultrastructural characteristics of active cells with large nuclei, well developed rough endoplasmic reticulum, multiple ribosomes, poorly developed Golgi apparatus, elliptical mitochondria and oval lysosomes. The electron microscopy also confirmed the presence of adipocytes, mast cells, myelinated and unmyelinated nerve fibers and chaotically oriented collagen fibers.CONCLUSION Significant differences exist between the normal structure of the ligament and the epiligament whose morphology and function is to be studied further.展开更多
In the published literature as well as in the most commonly used textbooks, the lateral collateral ligament (LCL) is described as having 1 attachment at the lateral epicondyle of the femur and another at the head of t...In the published literature as well as in the most commonly used textbooks, the lateral collateral ligament (LCL) is described as having 1 attachment at the lateral epicondyle of the femur and another at the head of the fibula. In this article, we reconsider the attachments, the length of the LCL, and the tissues surrounding the LCL by presenting our anatomical observations and by reviewing the literature. Our results have shown that the LCL is not only attached to the lower part of the lateral epicondyle of the femur, but also extends to the upper part of the lateral epicondyle. The attachment of the LCL on the fibula is enclosed by 2 insertion points of the biceps femoris tendon. The average length of the LCL in 71 knees was 51.4 mm. There is an “incomplete gap” on the LCL that is interrupted under the tendon of the biceps femoris.展开更多
文摘The importance of ligaments in providing joint stability and the incidence of injuries, dictates a need to increase their structural and mechanical properties understanding. Additionally, one of the challenges in the orthopedic industry is to design TKA （total knee arthroplasty） aiming to be soft-tissues friendly. This requires a priori knowledge of physiological knee function, in which the passive stability is achieved and guaranteed by the complex envelope of soft tissues around the joint. Therefore, the knowledge of the mechanical behavior of knee ligaments is fundamental. For this reason, our study aims to define and apply in a pilot study, an ad-hoc methodology to mechanically characterize ligaments of native human knees. The cruciate and collateral ligaments from a fresh frozen cadaver leg were accurately harvested. Each ligament was independently tested during a tensile test at different strain rates, simulating different deformation speeds during gait. Moreover, additional tensile tests until failure were also performed. Axial force and deformation were continuously recorded during each test. Results show that each ligament exhibited own typical non-linear, speed-related behavior. High repeatability in the results is observed among the different repeated tests confirming the robustness of the used methodology. This information will be helpful for clinicians, engineers and researchers to improve the biomechanical knowledge about knee, to develop better implants and to be able to improve the currently available numerical models of the human knee.
文摘AIM To examine the normal morphology of the epiligament tissue of the knee medial collateral ligament(MCL) in humans. METHODS Several samples of the mid-substance of the MCL of the knee joint from 7 fresh human cadavers(3 females and 4 males) were taken. Examination of the epiligament tissue was conducted by light microscopy and photomicrography on semi-thin sections of formalin fixed paraffin-embedded blocks that were routinely stained with haematoxylin and eosin, Mallory stain and Van Gieson's stain. Electron microscopy of the epiligament tissue was performed on ultra-thin sections incubated in 1% osmium tetroxide and contrasted with 2.5% uranyl acetate, lead nitrate, and sodium citrate.RESULTS The current light microscopic study demonstrated that the epiligament of the MCL consisted of fibroblasts, fibrocytes, adipocytes, neuro-vascular bundles and numerous multidirectional collagen fibers. In contrast, the ligament body was poorly vascularised, composed of hypo-cellular fascicles which were formed of longitudinal groups of collagen fibers. Moreover, most of the vessels of the epiligament-ligament complex were situated in the epiligament tissue. The electron microscopic study revealed fibroblasts with various shapes in the epiligament substance. All of them had the ultrastructural characteristics of active cells with large nuclei, well developed rough endoplasmic reticulum, multiple ribosomes, poorly developed Golgi apparatus, elliptical mitochondria and oval lysosomes. The electron microscopy also confirmed the presence of adipocytes, mast cells, myelinated and unmyelinated nerve fibers and chaotically oriented collagen fibers.CONCLUSION Significant differences exist between the normal structure of the ligament and the epiligament whose morphology and function is to be studied further.
文摘In the published literature as well as in the most commonly used textbooks, the lateral collateral ligament (LCL) is described as having 1 attachment at the lateral epicondyle of the femur and another at the head of the fibula. In this article, we reconsider the attachments, the length of the LCL, and the tissues surrounding the LCL by presenting our anatomical observations and by reviewing the literature. Our results have shown that the LCL is not only attached to the lower part of the lateral epicondyle of the femur, but also extends to the upper part of the lateral epicondyle. The attachment of the LCL on the fibula is enclosed by 2 insertion points of the biceps femoris tendon. The average length of the LCL in 71 knees was 51.4 mm. There is an “incomplete gap” on the LCL that is interrupted under the tendon of the biceps femoris.
