Abstract An enriched finite element method for the multi‐dimensional Stefan problems is presented. In this standard basis with a discontinuity in derivative of temperature normal to interface. The approximation can then represent phase interface and associated gradient within an element. be evolved without re‐meshing or use artificial heat capacity techniques. described by level set function that updated stabilized scheme. Several examples are solved proposed demonstrate accuracy robustness...

Recent reports have highlighted the importance of an anatomic tunnel placement for anterior cruciate ligament (ACL) reconstruction. The purpose this study was to compare effect different positions single-bundle ACL reconstruction on knee biomechanics.Sixteen fresh-frozen cadaver knees were used. In one group (n = 8), following techniques used surgery: (1) anteromedial (AM) bundle (AM-AM), (2) posterolateral (PL) (PL-PL) and (3) conventional vertical (PL-high AM). other mid-position (MID-MID)...

Quantification of the cross-sectional area (CSA) anterior cruciate ligament (ACL) in different loading conditions is important for understanding native anatomy and thus achieving anatomic reconstruction. The ACL insertion sites are larger than midsubstance, isthmus (region smallest CSA) location may vary with load or flexion angle.To (1) quantify CSA along entire ACL, (2) describe isthmus, (3) explore relationship between length CSA, (4) validate magnetic resonance imaging (MRI) assessing...

Background: It has been demonstrated that double-bundle reconstruction of the posterior cruciate ligament restores knee kinematics better than does single-bundle reconstruction. The objective this study was to identify tibial insertion site and related osseous landmarks help guide surgeons in performance an anatomical ligament. Methods: Twenty-one unpaired human cadaver knees were evaluated. geometric data surface features its bundles studied with macroscopic observation three-dimensional...

The purpose of our study was to evaluate the relationship between graft placement and in situ force after anterior cruciate ligament (ACL) reconstruction.Magnetic resonance imaging (MRI) obtained for twelve human cadaveric knees. knees, intact deficient-ACL states, were subjected external loading conditions as follows: an tibial load 89 N at 0°, 15°, 30°, 45°, 60°, 90° flexion a combined rotatory (simulated pivot-shift) 5 Nm internal torque 7 valgus 30° flexion. Three ACL reconstructions...

Background: The effect of lateral meniscal posterior root tear and repair—commonly seen in clinical practice the setting anterior cruciate ligament (ACL) reconstruction—is not known. Purpose/Hypothesis: This study evaluated repair on biomechanics ACL-reconstructed knee. It was hypothesized that tibial translation would increase under loading simulated pivot-shift with meniscus, while reduce it close to noninjured state. Study Design: Controlled laboratory study. Methods: Thirteen...

The success of posterior cruciate ligament reconstruction has varied. objective this study was to determine quantitatively and qualitatively the topography osseous landmarks femoral footprints anterolateral posteromedial bundles in order enhance repair.Twenty unpaired knees from twenty human cadavers were evaluated. surface features studied by means macroscopic observation three-dimensional laser photography.We observed, both visually with photography, an prominence located proximal...

Background: Although the literature has extensively discussed impingement after anterior cruciate ligament (ACL) reconstruction, definition of is vague, and pressure not been well investigated as a function tunnel position. Purpose: To determine amount between ACL posterior (PCL) notch roof in native ACL, single-bundle reconstruction with different placements, anatomical double-bundle reconstruction. Study design: Controlled laboratory study. Methods: Fifteen fresh-frozen nonpaired human...

Abstract An algorithm is presented which integrates different groups of nodes a finite element mesh with time steps and integrators. Since the nodal are updated independently no unsymmetric systems need be solved. Stability demonstrated by showing that an energy norm solution decreases after every update if step less than given critical value. The eigenvalue inequality theorem used to give in terms eigenvalues.

Background: High tunnel placement is common in single- and double-bundle anterior cruciate ligament (ACL) reconstructions. Similar nonanatomic may also occur ACL augmentation surgery. Purpose: In this study, situ forces knee kinematics were compared between high anteromedial (AM) anatomic AM a with isolated bundle injury. Study Design: Controlled laboratory study. Methods: Seven fresh-frozen cadaver knees used (age, 48 ± 12.5 years). First, intact was tested robotic–universal force sensor...

This study was done to determine whether there is a correlation between the notch volume and width index (NWI) as measured on three most frequently used radiographic views: Holmblad 45 degrees, 70 Rosenberg view. The of 20 cadaveric knees using Computed Tomography (CT). view radiographs were digitally re-created from CT scans for each specimen, NWI by two observers. Pearson coefficient calculated, well views. An independent t test performed difference in male female specimens. reliability...

Background Impact injury to articular cartilage can lead posttraumatic osteoarthritis. Hypotheses This study tests the hypotheses that (1) chondrocyte occurs after impact at energies insufficient fracture surface, and (2) patterns vary with energy, time injury, thickness. Study Design Controlled laboratory study. Methods Fresh bovine osteochondral cores were randomly divided into 5 groups: control, 0.35 J, (3) 0.71 (4) 1.07 (5) 1.43 J energies. Cores subjected computer-controlled loading...