scholarly journals The effect of a centralization procedure for extruded lateral meniscus on load distribution in porcine knee joints at different flexion angles

2019 ◽  
Author(s):  
Rei Kubota ◽  
Hideyuki Koga ◽  
Nobutake Ozeki ◽  
Junpei Matsuda ◽  
Yuji Kohno ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Articular Surface ◽  
Lateral Meniscus ◽  
Compressive Force ◽  
Knee Joints ◽  
Meniscal Extrusion ◽  
Hoop Strain ◽  
Axial Compressive Force ◽  
Tibial Cartilage ◽  
Porcine Knee

Abstract Background: Meniscal extrusion results in loss of the ability to resist hoop strain and biomechanical overload on the joint articular surface. A centralization technique has been developed to overcome these problems. In this study, we analyzed the biomechanics of the extruded and centralized lateral meniscus (LM) in porcine knee joints at different flexion angles. Methods: Porcine knee joints (n=8) were set in the universal tester and each knee was tested under the following states: 1) intact; 2) extrusion—meniscal extrusion was created by resecting the posterior root of the LM and posterior synovial capsule; and 3) centralization—centralization was performed by two anchors inserted in the lateral tibial plateau. Deviation distance of the meniscus, contact pressure, and contact area in the anterior LM, middle LM, posterior LM, and the contact pressure of the tibial cartilage were evaluated with an axial compressive force of 200 N at knee flexion angles of 30°, 45°, 60°, and 90°. Results: The deviation distance of LM significantly increased in extrusion but was restored to the intact status after centralization at all angles. Both the contact pressure and area significantly decreased in extrusion and were restored after centralization close to the intact status in the anterior and middle LM; in the posterior LM, however, decreased contact pressure and area were not restored after centralization. The contact pressure of the tibial cartilage increased significantly in extrusion but decreased close to the intact status after centralization. Conclusions: This centralization procedure could reduce extrusion of the LM and restore the load-distributing function of the anterior-middle LM. However, the procedure itself could not restore hoop function in cases where the defect lies in the posterior LM.

scholarly journals The effect of a centralization procedure for extruded lateral meniscus on load distribution in porcine knee joints at different flexion angles

2020 ◽  
Author(s):  
Rei Kubota ◽  
Hideyuki Koga ◽  
Nobutake Ozeki ◽  
Junpei Matsuda ◽  
Yuji Kohno ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Articular Surface ◽  
Lateral Meniscus ◽  
Compressive Force ◽  
Knee Joints ◽  
Meniscal Extrusion ◽  
Hoop Strain ◽  
Axial Compressive Force ◽  
Tibial Cartilage ◽  
Porcine Knee

Abstract Background : Meniscal extrusion results in loss of the ability to resist hoop strain and biomechanical overload on the joint articular surface. A centralization technique has been developed to overcome these problems. In this study, we analyzed the biomechanics of the extruded and centralized lateral meniscus (LM) in porcine knee joints at different flexion angles. Methods : Porcine knee joints (n=8) were set in the universal tester and each knee was tested under the following states: 1) intact; 2) extrusion—meniscal extrusion was created by resecting the posterior root of the LM and posterior synovial capsule; and 3) centralization—centralization was performed by two anchors inserted in the lateral tibial plateau. Deviation distance of the meniscus, contact pressure, and contact area in the anterior LM, middle LM, posterior LM, and the contact pressure of the tibial cartilage were evaluated with an axial compressive force of 200 N at knee flexion angles of 30°, 45°, 60°, and 90°. Results : The deviation distance of LM significantly increased in extrusion but was restored to the intact status after centralization at all angles. Both the contact pressure and area significantly decreased in extrusion and were restored after centralization close to the intact status in the anterior and middle LM; in the posterior LM, however, decreased contact pressure and area were not restored after centralization. The contact pressure of the tibial cartilage increased significantly in extrusion but decreased close to the intact status after centralization. Conclusions : This centralization procedure could reduce extrusion of the LM and restore the load-distributing function of the anterior-middle LM. However, the procedure itself could not restore hoop function in cases where the defect lies in the posterior LM. (276 words)

scholarly journals The effect of a centralization procedure for extruded lateral meniscus on load distribution in porcine knee joints at different flexion angles

2020 ◽  
Author(s):  
Rei Kubota ◽  
Hideyuki Koga ◽  
Nobutake Ozeki ◽  
Junpei Matsuda ◽  
Yuji Kohno ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Articular Surface ◽  
Lateral Meniscus ◽  
Compressive Force ◽  
Knee Joints ◽  
Meniscal Extrusion ◽  
Hoop Strain ◽  
Axial Compressive Force ◽  
Tibial Cartilage ◽  
Porcine Knee

Abstract Background: Meniscal extrusion results in loss of the ability to resist hoop strain and biomechanical overload on the joint articular surface. A centralization technique has been developed to overcome these problems. In this study, we analyzed the biomechanics of the extruded and centralized lateral meniscus (LM) in porcine knee joints at different flexion angles.Methods: Porcine knee joints (n=8) were set in the universal tester and each knee was tested under the following states: 1) intact; 2) extrusion—meniscal extrusion was created by resecting the posterior root of the LM and posterior synovial capsule; and 3) centralization—centralization was performed by two anchors inserted in the lateral tibial plateau. Deviation distance of the meniscus, contact pressure, and contact area in the anterior LM, middle LM, posterior LM, and the contact pressure of the tibial cartilage were evaluated with an axial compressive force of 200 N at knee flexion angles of 30°, 45°, 60°, and 90°.Results: The deviation distance of LM significantly increased in extrusion but was restored to the intact status after centralization at all angles. Both the contact pressure and area significantly decreased in extrusion and were restored after centralization close to the intact status in the anterior and middle LM; in the posterior LM, however, decreased contact pressure and area were not restored after centralization. The contact pressure of the tibial cartilage increased significantly in extrusion but decreased close to the intact status after centralization.Conclusions: This centralization procedure could reduce extrusion of the LM and restore the load-distributing function of the anterior-middle LM. However, the procedure itself could not restore hoop function in cases where the defect lies in the posterior LM.

scholarly journals The effect of a centralization procedure for extruded lateral meniscus on load distribution in porcine knee joints at different flexion angles

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Rei Kubota ◽  
Hideyuki Koga ◽  
Nobutake Ozeki ◽  
Junpei Matsuda ◽  
Yuji Kohno ◽  
...  
Keyword(s):  
Load Distribution ◽  
Lateral Meniscus ◽  
Knee Joints ◽  
Porcine Knee

scholarly journals Biomechanical analysis of a centralization procedure for extruded lateral meniscus after meniscectomy in porcine knee joints

2021 ◽  
Author(s):  
Yuji Kohno ◽  
Hideyuki Koga ◽  
Nobutake Ozeki ◽  
Junpei Matsuda ◽  
Mitsuru Mizuno ◽  
...  
Keyword(s):  
Lateral Meniscus ◽  
Biomechanical Analysis ◽  
Knee Joints ◽  
Porcine Knee

Experimental and Finite Element Investigations on the Biomechanical Effects of Meniscal Tears in the Knee Joint: A Review

2021 ◽  
Vol 50 ◽  
pp. 1-14
Author(s):  
Ashwin Kumar Devaraj ◽  
Kiran Kumar V. Acharya ◽  
Raviraja Adhikari
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Knee Joint ◽  
Contact Pressure ◽  
Medial Meniscus ◽  
Lateral Meniscus ◽  
Knee Joints ◽  
Meniscal Tears ◽  
Element Analysis ◽  
Biomechanical Response

The knowledge of the complex biomechanical behaviour of the injured knee joints is of paramount importance in various clinical situations. A review of the biomechanical effects of meniscal tears based on experimental and finite element analysis has not been reported in the literature. The objective of this study is to present a review of experimental and finite element investigations on the consequences of meniscal tears such as longitudinal, radial, horizontal cleavage and root tears in the medial and lateral menisci. It is found that larger longitudinal tear in the medial meniscus has a significant impact on the magnitude of strain in the meniscus associated with a dramatic increase in CP in the tibial cartilage. Also, the untreated fragment of the torn meniscus leads to a significant rise in contact pressure in the cartilage resulting in the progressive degeneration of the cartilage surface. The radial tears in the lateral meniscus of more than 66% width and those in the medial meniscus of more than 75% width result in a substantial increase in the contact pressure in the cartilage compared to that in the intact knee joint. The root tears in the menisci demonstrate a significant influence on the biomechanical response of the knee joint. The results of finite element analysis studies are compared with experimental findings. Finally, some recommendations for future work are proposed to predict the realistic biomechanical response of the knee joints with meniscal tears. The results of this study present a rationale that could help surgeons in making clinical decisions when managing patients with meniscal tears.

Outcomes More Than 2 Years After Meniscal Repair for Longitudinal Tears of the Lateral Meniscus Combined With Anterior Cruciate Ligament Reconstruction

2021 ◽  
pp. 036354652098197
Author(s):  
Akira Tsujii ◽  
Yasukazu Yonetani ◽  
Kazutaka Kinugasa ◽  
Tomohiko Matsuo ◽  
Kenji Yoneda ◽  
...  
Keyword(s):  
Ligament Reconstruction ◽  
Cruciate Ligament ◽  
Lateral Meniscus ◽  
Complete Healing ◽  
Control Group ◽  
Study Group ◽  
Meniscal Extrusion ◽  
Second Look ◽  
Anterior Cruciate

Background: Meniscal function after repair of longitudinal tears of the lateral meniscus (LM) with anterior cruciate ligament reconstruction (ACLR) has not been comprehensively investigated. Purpose: To evaluate not only the clinical outcomes and radiographic findings of patients who underwent repair of longitudinal tears of the LM combined with ACLR but also the healing status of the repaired meniscus and changes in chondral status with second-look arthroscopy. Study Design: Case series; Level of evidence, 4. Methods: Among 548 patients who underwent primary anatomic ACLR at our institution between 2010 and 2017, 39 who had concomitant longitudinal tears of the LM and underwent repair were studied. During follow-up for more than 2 years, all patients were evaluated clinically (pain, range of motion, swelling, and knee instability) and with imaging (plain radiograph and magnetic resonance imaging [MRI]), and compared with a matched control group (based on age, sex, body mass index, and follow-up period) without any concomitant injuries who underwent ACLR. Measurements on MRI were recorded preoperatively, immediately after surgery, and at final follow-up, and the change in the values over time was assessed. Of the 39 patients in each group, 24 were assessed by second-look arthroscopy with hardware removal 2 years postoperatively. Results: The mean follow-up times of the study and control group were at a mean of 42.4 and 45.4 months, respectively. There were no significant differences in clinical findings, lateral joint space narrowing on radiographs, and chondral status at the lateral compartment between groups, whereas lateral and posterior meniscal extrusion on MRI progressed significantly in the study group (0.43 ± 1.0 mm vs -0.29 ± 1.1 mm, P = .003; 1.9 ± 1.9 mm vs 0.14 ± 1.1 mm, P < .0001, respectively). Second-look arthroscopy revealed complete healing in 12 patients (50%), partial healing in 9 (37.5%), and failure in 3 (12.5%) in the study group, and no new tear in the control group. Conclusion: The clinical and imaging outcomes after repair of longitudinal tears of the LM combined with anatomic ACLR were successful and comparable with those after isolated ACLR without any other injuries at 42 months postoperatively, although meniscal extrusion showed progression on coronal/sagittal MRI. Based on the MRI findings and the result that only half of patients achieved complete healing, meniscal function could not be fully restored even after repair. Although degenerative changes were not apparent, longer-term follow-up is needed.

THU0062 FUNCTIONAL MR IMAGING OF HUMAN MENISCUS IS ASSOCIATED WITH HISTOLOGICAL DEGENERATION

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 243-243
Author(s):  
P. Sewerin ◽  
L. Dötsch ◽  
D. Truhm ◽  
D. Abrar ◽  
S. Nebelung
Keyword(s):  
Mr Imaging ◽  
T2 Mapping ◽  
Lateral Meniscus ◽  
Compressive Force ◽  
The Body ◽  
Quantitative Mri ◽  
Imaging Biomarker ◽  
Body Region ◽  
Deutschland Gmbh ◽  
Loading Device

Background:In OA, there is a close association of meniscus and cartilage pathologies. Meniscus degeneration and lesioning are critical risk factors for development of early OA. Hence, thisex-vivostudy assessed the responses to standardized loading of human meniscus samples as a function of degeneration and based on changes in their T1, T2 and T1ρ maps (as surrogate parameters of the tissue’s functionality).Objectives:Can meniscus functionality be visualized by serial quantitative MRI mapping technics?Methods:During total knee replacements, 45 meniscus samples of variable degeneration were harvested from the center of the lateral meniscus body (Fig. 1a1-a3). After preparation to standard, samples were subject to force-controlled loading using an MRI-compatible lever device that created compressive loading by torque ((Fig. 1a4-a5). For each sample and loading position, MRI measurements (as detailed below) were performed in the unloaded (δ0) and loaded configurations, i.e. loaded to 2 bar (δ1, 37.1 N compressive force, 0.67 Nm torque) and to 4 bar (δ2, 69.1 N, 1.24 Nm). Throughout all loading positions, morphological and quantitative imaging was performed using Proton Density-weighted and T1, T1ρ, and T2 mapping sequences (3.0 T, Achieva, Philips) based on standard turbospin-echo, inversion-recovery, spin-lock multi-gradient-echo, and multi-spin-echo sequences. For reference purposes, histological (i.e. Pauli classification) and biomechanical measures (i.e. Elastic Modulus) were obtained for each sample. Based on Pauli sum scores, samples were trichotomized as grossly intact, (n=14), mildly degenerated (n=16), and moderate-to-severely degenerated (n=15).Figure 1.Preparation of meniscus samples and details of the MRI-compatible loading device. The lateral meniscus (a1) was cut to standard size by use of a dedicated cutting block (a2) to eventually obtain lateral meniscus samples (from the body region) of standard dimensions (a3). These samples were then placed in a dedicated MRI-compatible loading device for pressure-controlled, quasi-static and torque-induced loading under simultaneous MR imaging (a4). Two parallel support beams allowed standardized positioning in the MRI scanner‘s bore (a5).Results:Morphologically, loading induced deformation and flattening in all samples (Fig. 2a). For T1, homogeneous loading-induced decreases in all samples were found, irrespective of degeneration (Fig. 2b). For T1ρ, increases in the apical zones of intact samples were observed, and decreases in degenerated samples (Fig. 2c). For T2, changes were ambiguous and incoherent (Fig. 2d).Figure 2.Serial morphological images and functional maps of histologically moderately degenerative human meniscus as a function of force-controlled loading. Serial PDw (a), T1 (b), T1ρ (c), and T2 maps (d) are displayed at increasing loading intensity (δ0: unloaded [a1-d1]; δ1: loaded to 2 bar [a2-d2]; δ2: loaded to 4 bar [a3-d3]). Histologically, this sample demonstrated signs of severe surface desintegration and disruption. Pauli sum score 12, i.e. moderate to severe degeneration (Pauli Grade III). In b – d, color-coded parameter value maps are overlaid onto the corresponding morphological images. Histological sections are stained with Hematoxylin-Eosin (e1) and Safranin O (e2).Conclusion:Meniscus functionality may be visualized using serial quantitative MRI mapping techniques. T1ρ may provide an imaging biomarker of relevant intra-tissue adaptations that seem to be associated with histological degeneration. The perspective evaluation of meniscus functionality may be indicative of incipient or manifest load transmission failure to the adjacent cartilage layer.Disclosure of Interests:Philipp Sewerin Grant/research support from: AbbVie Deutschland GmbH & Co. KGBristol-Myers Squibb Celgene GmbHLilly Deutschland GmbHNovartis Pharma GmbH Pfizer Deutschland GmbHRheumazentrum Rhein-Ruhr, Consultant of: AMGEN GmbH AbbVie Deutschland GmbH & Co. KG Biogen GmbHBristol-Myers Squibb Celgene GmbH Chugai Pharma arketing Ltd. / Chugai Europe GmbHHexal Pharma Janssen-CilagGmbH Johnson & Johnson Deutschland GmbHLilly Deutschland GmbH / Lilly Europe / Lilly Global Novartis Pharma GmbH Pfizer Deutschland GmbH Roche Pharma Rheumazentrum Rhein-Ruhr Sanofi-Genzyme Deutschland GmbH Swedish Orphan Biovitrum GmbH UCB Pharma GmbH, Speakers bureau: AMGEN GmbH AbbVie Deutschland GmbH & Co. KG Biogen GmbHBristol-Myers Squibb Celgene GmbH Chugai Pharma arketing Ltd. / Chugai Europe GmbHHexal Pharma Janssen-CilagGmbH Johnson & Johnson Deutschland GmbHLilly Deutschland GmbH / Lilly Europe / Lilly Global Novartis Pharma GmbH Pfizer Deutschland GmbH Roche Pharma Rheumazentrum Rhein-Ruhr Sanofi-Genzyme Deutschland GmbH Swedish Orphan Biovitrum GmbH UCB Pharma GmbH, Lisa Dötsch: None declared, Daniel Truhm: None declared, Daniel Abrar: None declared, Sven Nebelung: None declared

Effect of Coulomb Damping on Buckling of a Simply Supported Beam

1999 ◽  
Author(s):  
H. Yabuno ◽  
R. Oowada ◽  
N. Aoshima
Keyword(s):  
Compressive Force ◽  
Pitchfork Bifurcation ◽  
Steady States ◽  
Initial Condition ◽  
Axial Compressive Force ◽  
Simply Supported Beam ◽  
Simply Supported ◽  
Coulomb Damping ◽  
Buckling Behavior ◽  
Equilibrium Region

Abstract The present work describes a significant influence of a slight Coulomb damping on buckling of the simply supported beam subjected to an axial compressive force. Coulomb damping in the supporting points produces equilibrium regions around the well-known stable and unstable steady states under the pitchfork bifurcation which are analytically obtained in no consideration of the effect of Coulomb damping. After the transient response, the beam can stop any states in the equilibrium region, which becomes wider in the vicinity of the bifurcation point, depending on the initial condition. Also, the imperfection due to gravity is considered and it is theoretically shown that the equilibrium region is connected in the case when the imperfection due to gravity is relatively small comparing with the effect of the Coulomb damping, while the steady states under the pitchfork bifurcation in no consideration of the effect of Coulomb damping are necessarily disconnected by imperfection. Experimental results confirm the theoretically predicted effect of Coulomb damping in the supporting point on the buckling behavior of the beam.

scholarly journals Prevalence of Asymptomatic Intra-articular Changes of the Knee in Adult Professional Soccer Players

2019 ◽  
Vol 7 (11) ◽  
pp. 232596711988537 ◽  
Author(s):  
Eduard Nikolayevich Bezuglov ◽  
Anastasiya Vladimirovna Lyubushkina ◽  
Vladimir Yurevich Khaitin ◽  
Alisa Viktorovna Tokareva ◽  
Evgeny Nikolayevich Goncharov ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Femoral Condyle ◽  
Lateral Meniscus ◽  
Soccer Players ◽  
Knee Joints ◽  
Resonance Imaging ◽  
Cartilage Lesions ◽  
Professional Soccer ◽  
Meniscal Lesions

Background: Currently, there are few data on the association between participation in soccer and the condition of the knee joints in adult professional players. Hypothesis: A high percentage of professional soccer players will have asymptomatic intra-articular changes of the knee. Study Design: Cross-sectional study; Level of evidence, 3. Methods: The condition of the intra-articular structures (osteophytes, cartilage, and menisci) in 94 knee joints of 47 adult professional soccer players (mean ± SD age, 25.7 ± 4.6 years; body mass index, 22.8 ± 1.4 kg/m2) was analyzed. A 1.5-T magnetic resonance imaging scanner was used to perform the imaging, and the anonymized data were analyzed by 2 experienced radiologists. Results: Cartilage of both knee joints was affected in 97.9% of soccer players. Meniscal lesions were detected in 97.8% of joints, affecting both joints in 93.6% of athletes. Grade 2 cartilage lesions were the most prevalent (36%-60% depending on the lesion site), and grade 4 lesions were detected in 12.7% of joints. The medial femoral condyle and medial tibial plateau were most frequently affected by cartilage lesions (85.1%). Among meniscal lesions, grade 2 lesions were the most prevalent, being detected in 71% of the cases. Grade 3 lesions were detected in 13.8% of the joints. The posterior horn of the lateral meniscus was the most common site of meniscal lesions (affected in 95.7% of the joints). Osteophytes were detected in 4.2% of joints. Conclusion: The prevalence of asymptomatic cartilage and meniscal lesions in the knees of adult professional soccer players is extremely high and is not associated with the reduction of sports involvement. This research should promote the correct interpretation of magnetic resonance imaging data obtained from soccer players with acute trauma and the reduction of the number of unwarranted surgical procedures.

Biomechanical Study of Lumbar Spine (L2-L4) Using Hybrid Stabilization Device - A Finite Element Analysis

2020 ◽  
Vol 10 (1) ◽  
pp. 20-32 ◽  
Author(s):  
Pushpdant Jain ◽  
Mohammed Rajik Khan
Keyword(s):  
Finite Element ◽  
Compressive Force ◽  
Element Model ◽  
Biomechanical Study ◽  
Bottom Surface ◽  
Element Analysis ◽  
Axial Compressive Force ◽  
Hybrid Stabilization ◽  
Flexion Extension ◽  
Lumbar Segment

Spinal instrumentations have been designed to alleviate lower back pain and stabilize the spinal segments. The present work aims to evaluate the biomechanical effect of the proposed Hybrid Stabilization Device (HSD). Non-linear finite element model of lumbar segment L2-L4 were developed to compare the intact spine (IS) with rigid implant (RI) and hybrid stabilization device. To restrict all directional motion vertebra L4 bottom surface were kept fixed and axial compressive force of 500N with a moment of 10Nm were applied to the top surface of L2 vertebrae. The results of range of motion (ROM), intervertebral disc (IVD) pressure and strains for IVD-23 and IVD-34 were determined for flexion, extension, lateral bending and axial twist. Results demonstrated that ROM of HSD model is higher than RI and lower as compared to IS model. The predicted biomechanical parameters of the present work may be considered before clinical implementations of any implants.

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