Knee Joint Models for Kneeling Biomechanics

2014 ◽  
pp. 99-108
Keyword(s):  
Knee Joint ◽  
Joint Models

scholarly journals Simulation Case Study: Using Simscape for Human Knee Joint Models

2019 ◽  
Vol 29 (2) ◽  
pp. 101-104
Author(s):  
Ruth Leskovar ◽  
Andreas Körner ◽  
Felix Breitenecker
Keyword(s):  
Knee Joint ◽  
Joint Models ◽  
Human Knee ◽  
Human Knee Joint

scholarly journals The MRI posterior drawer test to assess posterior cruciate ligament functionality and knee joint laxity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lena Marie Wollschläger ◽  
Karl Ludger Radke ◽  
Justus Schock ◽  
Niklas Kotowski ◽  
David Latz ◽  
...  
Keyword(s):  
Knee Joint ◽  
Posterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Joint Laxity ◽  
Knee Joints ◽  
Joint Models ◽  
Human Knee ◽  
Clinical Magnetic Resonance Imaging ◽  
Magnetic Resonance Imaging Mri ◽  
Therapeutic Decision Making

AbstractClinical Magnetic Resonance Imaging (MRI) of joints is limited to mere morphologic evaluation and fails to directly visualize joint or ligament function. In this controlled laboratory study, we show that knee joint functionality may be quantified in situ and as a function of graded posterior cruciate ligament (PCL)-deficiency by combining MRI and standardized loading. 11 human knee joints underwent MRI under standardized posterior loading in the unloaded and loaded (147 N) configurations and in the intact, partially, and completely PCL-injured conditions. For each specimen, configuration, and condition, 3D joint models were implemented to analyse joint kinematics based on 3D Euclidean vectors and their projections on the Cartesian planes. Manual 2D measurements served as reference. With increasing PCL deficiency, vector projections increased significantly in the anteroposterior dimension under loading and manual measurements demonstrated similar patterns of change. Consequently, if combined with advanced image post-processing, stress MRI is a powerful diagnostic adjunct to evaluate ligament functionality and joint laxity in multiple dimensions and may have a role in differentiating PCL injury patterns, therapeutic decision-making, and treatment monitoring.

scholarly journals Multi-Color and Multi-Material 3D Printing of Knee Joint Models

2020 ◽  
Author(s):  
Oliver Grimaldo Ruiz ◽  
Yasin Dhaher
Keyword(s):  
Knee Joint ◽  
Surgical Outcomes ◽  
Medical Training ◽  
Selection Process ◽  
Pharmaceutical Research ◽  
Tensile Tests ◽  
Joint Models ◽  
Medical Software ◽  
Custom Made ◽  
Operative Planning

Abstract BackgroundEvery year, 3DP provides more alternatives and solutions in the medical field. Applications such as custom-made prosthetics and implants, platforms for pharmaceutical research, and PSAMs are the immediate emerging trends. Certainly, 3DP advancement is the convergence of multiple factors including improvements in medical software, 3D printer evolution, availability of new printing materials, improved industry support, and increasing commitment from medical societies and regulators. The overarching theme of this study is centered on exploring possible PSAMs and 3DP applications for improving surgical outcomes in orthopedics, particularly in ACL-R as well as providing functional models for TKA.Methods3-Matic, Rhinoceros, and SolidWorks were used to create three 3D computer-generated PSAMs: (1) Knee Joint model, wherein collagen fibers matrix structure is mimicked, (2) ACL-R model using a BPTB graft, incorporating key surgical outcomes such as orientations-architecture and positions-dimensions of the tunnels, as well as a custom-made SG based on patella anatomy (3) TKA model considering custom-made CS implants with symmetric tibial bearing design. Before printing, mechanical uni-axial tensile tests of materials were conducted using an Instron S3300, following the ASTM designation D412-C. The printing materials selection process and matching with anatomical structures were based on the analysis of the mechanical pattern of the strain-stress curves from different combinations of Agilus30™. The Stratasys J750™ printer was used to manufacture the ACL-R model (previous study), the ACL-R model with SG, and the TKA model. ResultsThe combinations No. 1-4 were chosen for 3DP with elastic modules of 1.8-0.7 MPa and Pearson coefficients of 0.980-0.991 respectively. The PSAMs were tested manually simulating 50 flexo-extension cycles without presenting ruptures, custom-made SG matches perfectly with PT anatomy. ConclusionFunctional PSAMs were printed with high fidelity, considerable cost, and short duration from planning to manufacturing. These coincided completely with 3D computer-generated PSAMs replicating fibers and features of the Knee Joint anatomy. The proposed PSAMs can be considered as an alternative to replacing cadaver specimens for medical training, pre-operative planning, education purposes, and validation of predictive models. We highlight the potential of PolyJet manufacturing combined with specialized medical software as a path to change the way specialists and researchers plan, execute, and validate complex procedures.

scholarly journals A Pilot Clinical Study of Hyperacute Serum Treatment in Osteoarthritic Knee Joint: Cytokine Changes and Clinical Effects

2021 ◽  
Vol 43 (2) ◽  
pp. 637-649
Author(s):  
Isabel Olmos Calvo ◽  
Eszter Fodor ◽  
Dorottya Kardos ◽  
István Hornyák ◽  
Adél Hinsenkamp ◽  
...  
Keyword(s):  
Synovial Fluid ◽  
Knee Joint ◽  
Symptomatic Relief ◽  
Clinical Effects ◽  
Joint Stability ◽  
Joint Models ◽  
Osteoarthritic Knee ◽  
Fluid Analysis ◽  
Pilot Clinical Study

The serum fraction of platelet-rich fibrin (hyperacute serum) has been shown to improve cartilage cell proliferation in in vitro osteoarthritic knee joint models. We hypothesize that hyperacute serum may be a potential regenerative therapeutic for osteoarthritic knees. In this study, the cytokine milieu at the synovial fluid of osteoarthritic knee joints exposed to hyperacute serum intraarticular injections was investigated. Patients with knee osteoarthritis received three injections of autologous hyperacute serum; synovial fluid was harvested before each injection and clinical monitoring was followed-up for 6 months. Forty osteoarthritic-related cytokines, growth factors and structural proteins from synovial fluid were quantified and analysed by Multivariate Factor Analysis. Hyperacute serum provided symptomatic relief regarding pain and joint stability for OA patients. Both patients “with” and “without effusion knees” had improved VAS, KOOS and Lysholm-Tegner scores 6 months after of hyperacute serum treatment. Synovial fluid analysis revealed two main clusters of proteins reacting together as a group, showing strong and significant correlations with their fluctuation patterns after hyperacute serum treatment. In conclusion, hyperacute serum has a positive effect in alleviating symptoms of osteoarthritic knees. Moreover, identified protein clusters may allow the prediction of protein expression, reducing the number of investigated proteins in future studies.

scholarly journals Comprehensive Assessment of Medial Knee Joint Instability by Valgus Stress MRI

Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1433
Author(s):  
Malin Ciba ◽  
Eva-Maria Winkelmeyer ◽  
Justus Schock ◽  
Philipp Schad ◽  
Niklas Kotowski ◽  
...  
Keyword(s):  
Knee Joint ◽  
Joint Instability ◽  
Cruciate Ligament ◽  
Medial Compartment ◽  
Joint Models ◽  
Valgus Stress ◽  
Joint Injury ◽  
Medial Knee ◽  
Anterior Cruciate ◽  
Therapeutic Decision Making

Standard clinical MRI techniques provide morphologic insights into knee joint pathologies, yet do not allow evaluation of ligament functionality or joint instability. We aimed to study valgus stress MRI, combined with sophisticated image post-processing, in a graded model of medial knee joint injury. To this end, eleven human cadaveric knee joint specimens were subjected to sequential injuries to the superficial medial collateral ligament (sMCL) and the anterior cruciate ligament (ACL). Specimens were imaged in 30° of flexion in the unloaded and loaded configurations (15 kp) and in the intact, partially sMCL-deficient, completely sMCL-deficient, and sMCL- and ACL-deficient conditions using morphologic sequences and a dedicated pressure-controlled loading device. Based on manual segmentations, sophisticated 3D joint models were generated to compute subchondral cortical distances for each condition and configuration. Statistical analysis included appropriate parametric tests. The medial compartment opened gradually as a function of loading and injury, especially anteriorly. Corresponding manual reference measurements by two readers confirmed these findings. Once validated in clinical trials, valgus stress MRI may comprehensively quantify medial compartment opening as a functional imaging surrogate of medial knee joint instability and qualify as an adjunct diagnostic tool in the differential diagnosis, therapeutic decision-making, and monitoring of treatment outcomes.

scholarly journals Rapid CT-based Estimation of Articular Cartilage Biomechanics in the Knee Joint Without Cartilage Segmentation

2020 ◽  
Vol 48 (12) ◽  
pp. 2965-2975
Author(s):  
Ali Mohammadi ◽  
Katariina A. H. Myller ◽  
Petri Tanska ◽  
Jukka Hirvasniemi ◽  
Simo Saarakkala ◽  
...  
Keyword(s):  
Knee Joint ◽  
Joint Disease ◽  
Fe Model ◽  
Fe Modeling ◽  
Joint Models ◽  
Modeling Framework ◽  
Tissue Responses ◽  
Automatic Model Generation ◽  
Magnetic Resonance Imaging Mri ◽  
Cartilage Biomechanics

AbstractKnee osteoarthritis (OA) is a painful joint disease, causing disabilities in daily activities. However, there is no known cure for OA, and the best treatment strategy might be prevention. Finite element (FE) modeling has demonstrated potential for evaluating personalized risks for the progression of OA. Current FE modeling approaches use primarily magnetic resonance imaging (MRI) to construct personalized knee joint models. However, MRI is expensive and has lower resolution than computed tomography (CT). In this study, we extend a previously presented atlas-based FE modeling framework for automatic model generation and simulation of knee joint tissue responses using contrast agent-free CT. In this method, based on certain anatomical dimensions measured from bone surfaces, an optimal template is selected and scaled to generate a personalized FE model. We compared the simulated tissue responses of the CT-based models with those of the MRI-based models. We show that the CT-based models are capable of producing similar tensile stresses, fibril strains, and fluid pressures of knee joint cartilage compared to those of the MRI-based models. This study provides a new methodology for the analysis of knee joint and cartilage mechanics based on measurement of bone dimensions from native CT scans.

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