Patellofemoral Joint Contact Pressures and Patellar Tracking for Activation of Individual Quadriceps Muscles

OrthoMedia ◽  
2022 ◽  
Orthopedics ◽  
2019 ◽  
Vol 42 (2) ◽  
pp. e172-e179 ◽  
Author(s):  
Jeffrey D. Osborne ◽  
S. Brandon Luczak ◽  
William B. Acker ◽  
James Bicos

2012 ◽  
Vol 27 (6) ◽  
pp. 595-601 ◽  
Author(s):  
Andrew Sawatsky ◽  
Doug Bourne ◽  
Monika Horisberger ◽  
Azim Jinha ◽  
Walter Herzog

1993 ◽  
Vol 26 (3) ◽  
pp. 352 ◽  
Author(s):  
Janet L. Ronsky ◽  
Walter Herzog ◽  
Thomas D. Brown ◽  
Tim Leonard

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Joshua E. Johnson ◽  
Phil Lee ◽  
Terence E. McIff ◽  
E. Bruce Toby ◽  
Kenneth J. Fischer

Joint injuries and the resulting posttraumatic osteoarthritis (OA) are a significant problem. There is still a need for tools to evaluate joint injuries, their effect on joint mechanics, and the relationship between altered mechanics and OA. Better understanding of injuries and their relationship to OA may aid in the development or refinement of treatment methods. This may be partially achieved by monitoring changes in joint mechanics that are a direct consequence of injury. Techniques such as image-based finite element modeling can provide in vivo joint mechanics data but can also be laborious and computationally expensive. Alternate modeling techniques that can provide similar results in a computationally efficient manner are an attractive prospect. It is likely possible to estimate risk of OA due to injury from surface contact mechanics data alone. The objective of this study was to compare joint contact mechanics from image-based surface contact modeling (SCM) and finite element modeling (FEM) in normal, injured (scapholunate ligament tear), and surgically repaired radiocarpal joints. Since FEM is accepted as the gold standard to evaluate joint contact stresses, our assumption was that results obtained using this method would accurately represent the true value. Magnetic resonance images (MRI) of the normal, injured, and postoperative wrists of three subjects were acquired when relaxed and during functional grasp. Surface and volumetric models of the radiolunate and radioscaphoid articulations were constructed from the relaxed images for SCM and FEM analyses, respectively. Kinematic boundary conditions were acquired from image registration between the relaxed and grasp images. For the SCM technique, a linear contact relationship was used to estimate contact outcomes based on interactions of the rigid articular surfaces in contact. For FEM, a pressure-overclosure relationship was used to estimate outcomes based on deformable body contact interactions. The SCM technique was able to evaluate variations in contact outcomes arising from scapholunate ligament injury and also the effects of surgical repair, with similar accuracy to the FEM gold standard. At least 80% of contact forces, peak contact pressures, mean contact pressures and contact areas from SCM were within 10 N, 0.5 MPa, 0.2 MPa, and 15 mm2, respectively, of the results from FEM, regardless of the state of the wrist. Depending on the application, the MRI-based SCM technique has the potential to provide clinically relevant subject-specific results in a computationally efficient manner compared to FEM.


2013 ◽  
Vol 39 (4) ◽  
pp. 978-987 ◽  
Author(s):  
Emily J. McWalter ◽  
Colm M. O'Kane ◽  
David P. FitzPatrick ◽  
David R. Wilson

Author(s):  
Andrew E. Anderson ◽  
Steve A. Maas ◽  
Benjamin J. Ellis ◽  
Jeffrey A. Weiss

Simplified analytical approaches to estimate hip joint contact pressures using perfectly spherical geometry have been described in the literature (rigid body spring models); however, estimations based on these simulations have not corresponded well with experimental in vitro data. Recent evidence from our laboratory suggests that finite element (FE) models of the hip joint that incorporate detailed geometry for cartilage and bone can predict cartilage pressures in good agreement with experimental data [1]. However, it is unknown whether this degree of model complexity is necessary. The objective of this study was to compare cartilage contact pressure predictions from FE models with varying degrees of simplicity to elucidate which aspects of hip morphology are required to obtain accurate predictions of cartilage contact pressure. Models based on 1) subject-specific (SS) geometry, 2) spheres, and 3) rotational conchoids were analyzed.


2009 ◽  
Vol 30 (8) ◽  
pp. 767-772 ◽  
Author(s):  
Dong Gil Lee ◽  
Brian L. Davis

Background: One of the more serious diabetic complications is Charcot neuroarthropathy (CN), a disease that results in arch collapse and permanent foot deformity. However, very little is known about the etiology of CN. From a mechanical standpoint, it is likely that there is a “vicious circle” in terms of (i) arch collapse causing increased midfoot joint pressures, and (ii) increased joint contact pressures exacerbating the collapse of midfoot bones. This study focused on assessment of peak joint pressure difference between diabetic and non-diabetic cadaver feet during simulated walking. We hypothesized that joint pressures are higher for diabetics than normal population. Materials and Methods: Sixteen cadaver foot specimens (eight control and eight diabetic specimens) were used in this study. Human gait at 25% of typical walking speed (averaged stance duration of 3.2s) was simulated by a custom-designed Universal Musculoskeletal Simulator. Four medial midfoot joint pressures (the first metatarsocuneiform, the medial naviculocuneiform, the middle naviculocuneiform, and the first intercuneiform) were measured dynamically during full stance. Results: The pressures in each of the four measured midfoot joints were significantly greater in the diabetic feet ( p = 0.015, p = 0.025, p < 0.001, and p = 0.545, respectively). Conclusion: Across all four tested joints, the diabetic cadaver specimens had, on average, 46% higher peak pressures than the control cadaver feet during the simulated stance phase. Clinical Relevance: This finding suggests that diabetic patients could be predisposed to arch collapse even before there are visible signs of bone or joint abnormalities.


2018 ◽  
Vol 4 (1) ◽  
pp. 203-205
Author(s):  
Mehdi Saeidi ◽  
Maziar Ramezani ◽  
Piaras Kelly ◽  
Mohd Sabri Hussin ◽  
Thomas Neitzert

AbstractThis research aimed to study the efficacy of a novel implant for osteoarthritic knees. This implant is designed to eliminate excessive loads through the knee and to provide suitable conditions for possible tibiofemoral cartilage regeneration. The implant was designed for the medial side of the knee joint. Finite Element Analysis (FEA) was performed for an extended knee position of the knee joint. Contact pressure distributions on the medial and lateral compartments were investigated as well as stress distributions throughout the implant’s plates. Results with and without the implant were compared, and it was seen that the contact pressures on the surface of the distal femur were reduced by more than 90% after the introduction of the implant.


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