3d knee modeling and biomechanical simulation dating, result filters
Materials and Methods 2. Tinteiros online dating material properties of the different tissues derived from literatures facilitate comparison with them. View at Google Scholar J. Even so, there were functional failure, prosthesis loosening or dislocation and the excessive wear of prosthesis, and so forth, postoperatively [ 23 ].
Optical tracking system Polaris hybrid optical tracking system, NDI, Calgary, AB, Canada was used to measure the trajectory of the femur, tibia, and patella under squat t ing for analysis of knee relative motion by coordinate transformation [ 21 ] Figure 5. Simulation predictions reasonably agreed with movement data acquired on a sample of cadaver knee specimens.
Therefore, if the tibia flexes 90 degrees at external rotation phase, it is possible to stretch to degree flexion with no lateral condyle backward-forward translation.
Figure 4 Open Knee can be used to understand mechanical function of tissue structures under varying joint loading conditions.
In this study, the distribution of medial and lateral contact stress was influenced by the joint position. With flexion growth, femoral relative tibial translated upward, inward and backward, respectively.
In high flexion, femoral condyle lifted off tibial surface a few millimeters and contacted with posterior meniscus. Then, a complete geometry simulation model of knee joint was built by registration of soft and bone tissues Figure 1. Meanwhile, with tibiofemoral joint flexing, the tibiofemoral joint pressure increased, and the tension of the quadriceps tendon and the patellar tendon increased.
Within 0- to degree flexion, tibial internal rotation increased 3.
Open Knee: Open Source Modeling and Simulation in Knee Biomechanics. - PubMed - NCBI
There were differences between the medial and the lateral tibiofemoral joint. The margin patella contacted with femoral epicondylus in higher flexion and decreased contact area causing higher contact stress Figures 17 and At the same time, there was always a contact zone concave area at the upper patella and the contact occurred in the intercondylar notch along with the medial and lateral contact, a recess located in the upper patella exactly matching with the trochlear.
From 0- to degree flexion, the contact stress was of about 9 MPa for both the simulation and the test results. The flexion motion and dynamic contact characteristics of knee were analyzed, and verified by comparing with the data from in vitro experiment. In 0—degree flexion, the contact of tibiofemoral joint mainly occurred in the front of tibia, and contact area was relatively small.
The geometries of bones, cartilage, menisci, and ligaments were individualized to the specimen and discretized into meshes.
Open Knee: Open Source Modeling and Simulation in Knee Biomechanics.
The biomechanical experimental system of knee was built to simulate knee squatting using cadaver knees. An anterior view of the whole mesh can be seen on the right. The signal interference of sensor, measurement errors of force transducer, contact stress sensor, reference frame, and calibration error can also cause measurement error.
So there are differences between the simulation and the results of the experiment, as well as between the specimen and living body. At the same time medial stress increased, which may be the reason of medial meniscus tear.
The change tendency was basically consistent in simulation and test Figures 15 and 16being slightly different. During 0—degree knees flexion, femur external rotation was average of 20 degrees, and femur abduction turned to average of 2 degrees. The meniscus can be regarded as elastic and isotropic in axial, radial, and circumferential direction, respectively [ 18 ].
However, the degree flexed position was the critical point of tibia in internal rotation. The relative translation of tibiofemoral joint in both test and FEA.
For dynamic movement measurement, three reference frames consisting of 14 mm diameter markers were fixed in tibia, femur, and patella, respectively.
By calculating the dynamic FEA of natural knee, the movement and joint contact stress of healthy knee could be obtained. All model components are defined on the posterior view of the model, which can be seen on the left. The patellofemoral joint translation motion results backward, distal, medial, or lateral translation also were approximate to other results [ 253335 ].
The in vitro experiment and simulation results were compared in this study, and there were differences between them. The cadaver experiment and FE results were compared in contrast diagram Figures 10 and The specimen was fixed into the experimental platform.
The data of markers were captured and the relative motions of patella, tibia, and femur were measured by the Polaris optical tracking system Figure 8. The accuracy of test was inevitably influenced by some of the characteristics of experiment system.
Especially for Asians, the relationship between mechanics and movement in high flexion should be fully understood.
Biomechanics | iMechanica
The adduction in higher flexion was caused and corresponded with the internal rotation of tibia relative to femur. Femoral condyle scrolled up to meniscus posterior horn, almost dislocation to the tibia. Contact area reduction within high flexion was likely the reason of high stress in high flexion, and the cause of high stress was not only from high loading.
Figure 2 Open Knee was used to simulate passive movements of the joint by prescribing tibiofemoral flexion and setting the remaining degrees of freedom free. There are different features of each tissue's material properties.