In-Vivo Force Estimation of the Anterior Cruciate Ligament

2009 ◽  
Author(s):  
Ali Hosseini ◽  
Thomas J. Gill ◽  
Guoan Li
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Force Estimation ◽  
Non Invasive ◽  
Injury Mechanisms ◽  
Invasive Method ◽  
Anterior Cruciate

The knowledge of in-vivo ACL forces is instrumental for understanding ACL injury mechanisms and for improving surgical ACL reconstruction techniques. Several in-vitro investigations have measured ACL forces in response to various loads applied to the knee. However, in-vivo ACL forces in response to controlled loading are still unknown. The objective of this study was to estimate the force of healthy ACL as well as the possible upper bound of ACL forces under an increasing axial tibial loading in living subjects using a non-invasive method.

Measuring Strain Distributions in the Anterior Cruciate Ligament Using Ultrasound

2010 ◽  
Author(s):  
Amy Cochran ◽  
Yingxin Gao ◽  
Ursula Krotscheck ◽  
Margret Thompson ◽  
James Stouffer ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Treatment Strategies ◽  
Acl Injury ◽  
Physiological Factors ◽  
Detailed Understanding ◽  
Prevention And Treatment ◽  
Anterior Cruciate ◽  
Tissue Motion

Optimal prevention and treatment strategies of anterior cruciate ligament (ACL) injury can be realized with a detailed understanding of how physiological factors impact the ACL. A noninvasive, in vivo method that assesses the ACL’s mechanical integrity is needed to help clarify this multi-factorial pathophysiology. We investigated the use of the noninvasive, in vivo technique, ultrasound strain elastography (USE) (1), to distinguish between normal and injured ACLs. USE is used as a diagnostic tool in oncological (2), hepatic (3), and cardiovascular (4) applications. This technique uses ultrasonic RF data to track tissue motion in order to estimate strain within the tissue.

REGENERATION OF ANTERIOR CRUCIATE LIGAMENT WITH SILK-BASED SCAFFOLD IN PORCINE MODEL

2015 ◽  
Vol 15 (01) ◽  
pp. 1550006 ◽  
Author(s):  
ZHENG LI ◽  
JIANKANG HE ◽  
XIANG LI ◽  
WEIGUO BIAN ◽  
WENYOU ZHANG ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Anterior Cruciate Ligament ◽  
Porcine Model ◽  
Cruciate Ligament ◽  
Silk Fibers ◽  
Bone Interface ◽  
Anterior Cruciate ◽  
Large Animals

Silk was widely investigated as a promising scaffold material in ligament tissue engineering. Although a variety of silk scaffolds were developed for the regeneration of anterior cruciate ligament (ACL) in vitro and in vivo, more investigations should be performed in large animals to translate these findings into clinical applications. The aim of this study is to evaluate the feasibility of using silk-based ACL scaffolds to regenerate damaged ACLs in porcine model. The microstructural organization, tissue regeneration as well as ligament-bone interface of silk implants were evaluated with scanning electron microscopy, micro-computerized tomography, histological and immunohistochemical staining at three and six months postoperatively. The results demonstrated that silk fibers in the ACL scaffolds organized in parallel similar with collagen fibers in native ligaments, which facilitated and guided the penetration of newly regenerated tissue into the pores among silk fibers. Collagen production especially collagen I in silk implants significantly increased from three to six months, and was gradually close to the level of native ligaments. At implant-bone interface, indirect ligament-bone insertion was observed at three months and substantial Sharpey's fibers formed at six months. The results indicated that the silk-based ACL scaffold provides a promising tissue engineering approach for ACL regeneration.

Silk fibroin coating through EDC/NHS crosslink is an effective method to promote graft remodeling of a polyethylene terephthalate artificial ligament

2019 ◽  
Vol 33 (10) ◽  
pp. 1407-1414 ◽  
Author(s):  
Jiangyu Cai ◽  
Li Zhang ◽  
Jun Chen ◽  
Shiyi Chen
Keyword(s):  
Anterior Cruciate Ligament ◽  
Anterior Cruciate Ligament Reconstruction ◽  
Polyethylene Terephthalate ◽  
Silk Fibroin ◽  
Ligament Reconstruction ◽  
Cruciate Ligament ◽  
Cruciate Ligament Reconstruction ◽  
Anterior Cruciate

Anterior cruciate ligament reconstruction using polyethylene terephthalate artificial ligaments is one of the research hotspots in sports medicine but it is still challenging to achieve biological healing. The purpose of this study was to modify polyethylene terephthalate ligament with silk fibroin through ethyl-3–(3-dimethylaminopropyl)carbodiimide (EDC)/N-hydroxysuccinimide (NHS) crosslink and to investigate the performance of graft remodeling in vitro and in vivo. After silk fibroin coating, changes in the surface properties of ligament were characterized by scanning electron microscopy, attenuated total reflectance-Fourier transform infrared spectroscopy and water contact angle measurements. The compatibility of polyethylene terephthalate ligament with silk fibroin coating was investigated in vitro. The results showed the silk fibroin coating significantly improved adhesion, proliferation and extracellular matrix secretion of fibroblast cells. Moreover, a rabbit anterior cruciate ligament reconstruction model was established to evaluate the effect of ligament with silk fibroin coating in vivo. The gross observation and histological results showed that the silk fibroin coating significantly inhibited inflammation response and promoted new tissue regeneration with fusiform cells infiltration in and around the graft. Furthermore, the expressions of collagen I protein and mRNA in the silk fibroin-coated polyethylene terephthalate group were much higher than those in the control group according to the immunohistochemical and real-time polymerase chain reaction results. Therefore, silk fibroin coating through EDC/NHS crosslink promotes the biocompatibility and remodeling process of polyethylene terephthalate artificial ligament in vitro and in vivo. It can be considered as a potential solution to the problem of poor remodeling of artificial ligaments after anterior cruciate ligament reconstruction in the clinical applications.

Does Graft Construct Lengthening at the Fixations Cause an Increase in Anterior Laxity Following Anterior Cruciate Ligament Reconstruction in vivo?

2010 ◽  
Vol 132 (8) ◽  
Author(s):  
Conrad K. Smith ◽  
M. L. Hull ◽  
S. M. Howell
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Bone Tunnel ◽  
Anterior Cruciate Ligament Graft ◽  
Potential Increase ◽  
Anterior Laxity ◽  
Fresh Frozen ◽  
Anterior Cruciate

A millimeter-for-millimeter relation between an increase in length of an anterior cruciate ligament graft construct and an increase in anterior laxity has been demonstrated in multiple in vitro studies. Based on this relation, a 3 mm increase in length of the graft construct following surgery could manifest as a 3 mm increase in anterior laxity in vivo, which is considered clinically unstable. Hence, the two primary objectives were to determine whether the millimeter-for-millimeter relation exists in vivo for slippage-resistant fixation of a soft-tissue graft and, if it does not exist, then to what extent the increase in stiffness caused by biologic healing of the graft to the bone tunnel offsets the potential increase in anterior laxity resulting from lengthening at the sites of fixation. Sixteen subjects were treated with a fresh-frozen, nonirradiated, nonchemically processed tibialis allograft. Tantalum markers were injected into the graft, fixation devices, and bones. On the day of surgery and at 1, 2, 3, and 4 months, Roentgen stereophotogrammetric analysis was used to compute anterior laxity at 150 N of anterior force and the total slippage from both sites of fixation. A simple linear regression was performed to determine whether the millimeter-for-millimeter relation existed and a springs-in-series model of the graft construct was used to determine the extent to which the increase in stiffness caused by biological healing of the graft to the bone tunnel offset the increase in anterior laxity resulting from lengthening at the sites of fixation. There was no correlation between lengthening at the sites of fixation and the increase in anterior laxity at 1 month (R2=0.0, slope=0.2). Also, the increase in stiffness of the graft construct caused by biologic healing of the graft to the bone tunnel offset 0.7 mm of the 1.5 mm potential increase in anterior laxity resulting from lengthening at the sites of fixation. This relatively large offset of nearly 50% occurred because lengthening at the sites of fixation was small.

scholarly journals An Anterior Cruciate Ligament In Vitro Rupture Model Based on Clinical Imaging

2021 ◽  
pp. 036354652110171
Author(s):  
Lukas Willinger ◽  
Kiron K. Athwal ◽  
Andy Williams ◽  
Andrew A. Amis
Keyword(s):  
Anterior Cruciate Ligament ◽  
Acl Reconstruction ◽  
Pivot Shift ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Bone Bruise ◽  
Acl Injuries ◽  
Anterior Cruciate ◽  
Acl Transection

Background: Biomechanical studies on anterior cruciate ligament (ACL) injuries and reconstructions are based on ACL transection instead of realistic injury trauma. Purpose: To replicate an ACL injury in vitro and compare the laxity that occurs with that after an isolated ACL transection injury before and after ACL reconstruction. Study Design: Controlled laboratory study. Methods: Nine paired knees were ACL injured or ACL transected. For ACL injury, knees were mounted in a rig that imposed tibial anterior translation at 1000 mm/min to rupture the ACL at 22.5° of flexion, 5° of internal rotation, and 710 N of joint compressive force, replicating data published on clinical bone bruise locations. In contralateral knees, the ACL was transected arthroscopically at midsubstance. Both groups had ACL reconstruction with bone–patellar tendon–bone graft. Native, ACL-deficient, and reconstructed knee laxities were measured in a kinematics rig from 0° to 100° of flexion with optical tracking: anterior tibial translation (ATT), internal rotation (IR), anterolateral (ATT + IR), and pivot shift (IR + valgus). Results: The ACL ruptured at 26 ± 5 mm of ATT and 1550 ± 620 N of force (mean ± SD) with an audible spring-back tibiofemoral impact with 5o of valgus. ACL injury and transection increased ATT ( P < .001). ACL injury caused greater ATT than ACL transection by 1.4 mm (range, 0.4-2.2 mm; P = .033). IR increased significantly in ACL-injured knees between 0° and 30° of flexion and in ACL transection knees from 0° to 20° of flexion. ATT during the ATT + IR maneuver was increased by ACL injury between 0° and 80° and after ACL transection between 0° and 60°. Residual laxity persisted after ACL reconstruction from 0° to 40° after ACL injury and from 0° to 20° in the ACL transection knees. ACL deficiency increased ATT and IR in the pivot-shift test ( P < .001). The ATT in the pivot-shift increased significantly at 0° to 20° after ACL transection and 0° to 50° after ACL injury, and this persisted across 0° to 20° and 0° to 40° after ACL reconstruction. Conclusion: This study developed an ACL injury model in vitro that replicated clinical ACL injury as evidenced by bone bruise patterns. ACL injury caused larger increases of laxity than ACL transection, likely because of damage to adjacent tissues; these differences often persisted after ACL reconstruction. Clinical Relevance: This in vitro model created more realistic ACL injuries than surgical transection, facilitating future evaluation of ACL reconstruction techniques.

scholarly journals α2-Macroglobulin-Rich Serum As a Master Inhibitor of Inflammatory Factors Attenuates Cartilage Degeneration in a Mini Pig Model of Osteoarthritis Induced By “Idealized” Anterior Cruciate Ligament Reconstruction

2021 ◽  
Author(s):  
Ruipeng Zhao ◽  
Xiaochun Wei ◽  
Chengming Zhang ◽  
Hongru Wu ◽  
Chuan Xiang ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Cartilage Degeneration ◽  
Mature Female ◽  
Inflammatory Factors ◽  
Post Surgery ◽  
Α2 Macroglobulin ◽  
Anterior Cruciate

Abstract Background: α2-Macroglobulin (α2M) is important for chondral protection in post-traumatic osteoarthritis (PTOA). However, its injection into xenogeneic joint cavities has safety hazards, limiting clinical applications. Exploring serum α2M-enriching strategies and the therapeutic effect and mechanism of α2M-rich serum (α2MRS) autologous joint injection to treat PTOA has significant value.Methods: A unique filtration process was used to concentrate α2M from serum. Human osteoarthritic chondrocytes induced with interleukin (IL)-1β were used to evaluate catabolic enzymes, cell proliferation, apoptosis, and gene expression 24h after α2MRS treatment. Eighteen mature female mini pigs were randomized to three groups, sham (n = 6), “idealized” anterior cruciate ligament autograft reconstruction (IACL-R) (n = 6), and IACL-R+α2MRS (n = 6). Expression of inflammatory factors in the synovial fluid (SF) was measured using Luminex assays. Gait features were recorded using the Tekscan Walkway system. The extent of PTOA progression was evaluated using imaging, real-time PCR , and histology 3 months post-surgery.Results: The α2M concentration in α2MRS was higher than that in human and mini pig serum, respectively. In vitro, α2MRS significantly promoted human chondrocyte proliferation (p < 0.001) and reduced apoptosis (p < 0.001) and chondrocyte catabolic cytokine gene transcription (p < 0.001) and secretion (p < 0.001). In vivo, SF concentrations of all tested inflammatory factors were significantly lower in the IACL-R+α2MRS group than in the IACL-R group (p < 0.001). All gait parameters in the IACL-R+α2MRS group returned to normal significantly early compared to those in the IACL-R group (p < 0.05). Imaging , histology, and biochemistry data showed that cartilage degeneration in the IACL-R+α2MRS group was significantly diminished relative to that in the IACL-R group (p < 0.001).Conclusion: Injecting α2MRS into the joint cavity after IACL-R can significantly delay articular cartilage degeneration.

scholarly journals Sex Comparisons of In Vivo Anterior Cruciate Ligament Morphometry

2019 ◽  
Vol 54 (5) ◽  
pp. 513-518 ◽  
Author(s):  
Hsin-Min Wang ◽  
Sandra J. Shultz ◽  
Scott E. Ross ◽  
Robert A. Henson ◽  
David H. Perrin ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Sex Differences ◽  
Injury Risk ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Cross Sectional ◽  
Notch Width ◽  
Anterior Cruciate ◽  
Femoral Notch

Context Females have consistently higher anterior cruciate ligament (ACL) injury rates than males. The reasons for this disparity are not fully understood. Whereas ACL morphometric characteristics are associated with injury risk and females have a smaller absolute ACL size, comprehensive sex comparisons that adequately account for sex differences in body mass index (BMI) have been limited. Objective To investigate sex differences among in vivo ACL morphometric measures before and after controlling for femoral notch width and BMI. Design Cross-sectional study. Setting Laboratory. Patients or Other Participants Twenty recreationally active men (age = 23.2 ± 2.9 years, height = 180.4 ± 6.7 cm, mass = 84.0 ± 10.9 kg) and 20 recreationally active women (age = 21.3 ± 2.3 years, height = 166.9 ± 7.7 cm, mass = 61.9 ± 7.2 kg) participated. Main Outcome Measure(s) Structural magnetic resonance imaging sequences were performed on the left knee. Anterior cruciate ligament volume, width, and cross-sectional area measures were obtained from T2-weighted images and normalized to femoral notch width and BMI. Femoral notch width was measured from T1-weighted images. We used independent-samples t tests to examine sex differences in absolute and normalized measures. Results Men had greater absolute ACL volume (1712.2 ± 356.3 versus 1200.1 ± 337.8 mm3; t38 = −4.67, P &lt; .001) and ACL width (8.5 ± 2.3 versus 7.0 ± 1.2 mm; t38 = −2.53, P = .02) than women. The ACL volume remained greater in men than in women after controlling for femoral notch width (89.31 ± 15.63 versus 72.42 ± 16.82 mm3/mm; t38 = −3.29, P = .002) and BMI (67.13 ± 15.40 versus 54.69 ± 16.39 mm3/kg/m2; t38 = −2.47, P = .02). Conclusions Whereas men had greater ACL volume and width than women, only ACL volume remained different when we accounted for femoral notch width and BMI. This suggests that ACL volume may be an appropriate measure of ACL anatomy in investigations of ACL morphometry and ACL injury risk that include sex comparisons.

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