scholarly journals Validation of an MRI-based method to assess patellofemoral joint contact areas in loaded knee flexion in vivo

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

Effect of Patellar Tendon Shortening on Tracking of the Patella

2005 ◽  
Vol 33 (10) ◽  
pp. 1565-1574 ◽  
Author(s):  
Neil Upadhyay ◽  
Samuel R. Vollans ◽  
Bahaa B. Seedhom ◽  
Roger W. Soames
Keyword(s):  
Patellar Tendon ◽  
Contact Area ◽  
Knee Flexion ◽  
Patellofemoral Joint ◽  
Contact Stresses ◽  
Contact Areas ◽  
Before And After ◽  
Joint Contact ◽  
Joint Biomechanics ◽  
Patellar Tendon Shortening

Background Although 10% postoperative patellar tendon shortening after bone–patellar tendon–bone autograft reconstruction of the anterior cruciate ligament has been reported, there are no published studies assessing the effect of shortening on patellofemoral joint biomechanics under physiological loading conditions. Purpose To investigate the influence of patellar tendon shortening on patellofemoral joint biomechanics. Study Design Controlled laboratory study. Methods The authors evaluated the patellofemoral contact area, the location of contact, and the patellofemoral joint reaction force and contact stresses in 7 cadaveric knees before and after 10% patellar tendon shortening. Shortening was achieved using a specially designed device. Experimental conditions simulating those occurring during level walking were employed: physiological quadriceps loads and corresponding angles of tibial rotation were applied at 15 °, 30 °, and 60 ° flexion of the knee. Patellofemoral joint contact areas were measured before and after shortening using the silicone oil–carbon black powder suspension squeeze technique. Results After patellar tendon shortening, patellofemoral joint contact areas were displaced proximally on the patellar surface and distally on the femoral surface. Although the contact area increased by 18% at 15 ° of knee flexion (P=. 04), no significant change occurred at 30 ° or 60 ° of knee flexion (P>. 05). Patellofemoral contact stress remained unchanged after patellar tendon shortening (P>. 05) at each flexion angle. Conclusion Our results suggest that a 10% shortening of the patellar tendon does not alter patellar contact stresses during locomotion. It is not clear whether apparent changes in contact location in all positions and contact area at 15 ° would have clinical consequences.

scholarly journals In Vivo Kinematics of the Extensor Mechanism of the Knee During Deep Flexion

2013 ◽  
Vol 135 (8) ◽  
Author(s):  
Koichi Kobayashi ◽  
Ali Hosseini ◽  
Makoto Sakamoto ◽  
Wei Qi ◽  
Harry E. Rubash ◽  
...  
Keyword(s):  
Patellar Tendon ◽  
Knee Flexion ◽  
Extensor Mechanism ◽  
Deep Flexion ◽  
Contact Points ◽  
Patellar Cartilage ◽  
Joint Contact ◽  
Joint Biomechanics ◽  
Few Data

While various factors have been assumed to affect knee joint biomechanics, few data have been reported on the function of the extensor mechanism in deep flexion of the knee. This study analyzed the patellofemoral joint contact kinematics and the ratio of the quadriceps and patellar tendon forces in living subjects when they performed a single leg lunge up to 150 deg of flexion. The data revealed that in the proximal-distal direction, the patellofemoral articular contact points were in the central one-third of the patellar cartilage. Beyond 90 deg of flexion, the contact points moved towards the medial-lateral edges of the patellar surface. At low flexion angles, the patellar tendon and quadriceps force ratio was approximately 1.0 but reduced to about 0.7 after 60 deg of knee flexion, implying that the patella tendon carries lower loads than the quadriceps. These data may be valuable for improvement of contemporary surgical treatments of diseased knees that are aimed to achieve deep knee flexion.

scholarly journals Patellofemoral joint contact area increases with knee flexion and weight-bearing

2005 ◽  
Vol 23 (2) ◽  
pp. 345-350 ◽  
Author(s):  
Thor F. Besier ◽  
Christine E. Draper ◽  
Garry E. Gold ◽  
Gary S. Beaupré ◽  
Scott L. Delp
Keyword(s):  
Contact Area ◽  
Knee Flexion ◽  
Patellofemoral Joint ◽  
Weight Bearing ◽  
Joint Contact

A Detailed and Validated Three Dimensional Dynamic Model of the Patellofemoral Joint

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Mohammad Akbar ◽  
Farzam Farahmand ◽  
Ali Jafari ◽  
Mahmoud Saadat Foumani
Keyword(s):  
Knee Flexion ◽  
Patellofemoral Joint ◽  
Muscle Activation ◽  
Model Simulation ◽  
Three Dimensional ◽  
Rigid Bodies ◽  
Patellar Tilt ◽  
Full Extension ◽  
Patellar Stability

A detailed 3D anatomical model of the patellofemoral joint was developed to study the tracking, force, contact and stability characteristics of the joint. The quadriceps was considered to include six components represented by 15 force vectors. The patellar tendon was modeled using four bundles of viscoelastic tensile elements. Each of the lateral and medial retinaculum was modeled by a three-bundle nonlinear spring. The femur and patella were considered as rigid bodies with their articular cartilage layers represented by an isotropic viscoelastic material. The geometrical and tracking data needed for model simulation, as well as validation of its results, were obtained from an in vivo experiment, involving MR imaging of a normal knee while performing isometric leg press against a constant 140 N force. The model was formulated within the framework of a rigid body spring model and solved using forth-order Runge-Kutta, for knee flexion angles between zero and 50 degrees. Results indicated a good agreement between the model predictions for patellar tracking and the experimental results with RMS deviations of about 2 mm for translations (less than 0.7 mm for patellar mediolateral shift), and 4 degrees for rotations (less than 3 degrees for patellar tilt). The contact pattern predicted by the model was also consistent with the results of the experiment and the literature. The joint contact force increased linearly with progressive knee flexion from 80 N to 210 N. The medial retinaculum experienced a peak force of 18 N at full extension that decreased with knee flexion and disappeared entirely at 20 degrees flexion. Analysis of the patellar time response to the quadriceps contraction suggested that the muscle activation most affected the patellar shift and tilt. These results are consistent with the recent observations in the literature concerning the significance of retinaculum and quadriceps in the patellar stability.

scholarly journals Relationship Between Patellofemoral Finite Helical Axis and Femoral Trans-Epicondyle Axis Using a Static Magnetic Resonance-Based Methodology

2020 ◽  
Author(s):  
Zhenguo Yu ◽  
Hong Cai ◽  
Bin Yang ◽  
Jie Yao ◽  
Ke Zhang ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Knee Flexion ◽  
Patellofemoral Joint ◽  
Spline Interpolation ◽  
Joint Kinematics ◽  
Helical Axis ◽  
Mr Images ◽  
Maximum Angle ◽  
Finite Helical Axis

Abstract Background: To manage patellofemoral joint disorders, a complete understanding of the in vivo patellofemoral kinematics is critical. However, as one of the parameters of joint kinematics, the location and orientation of patellofemoral finite helical axis (FHA) remains unclear. The purpose of this study is to quantify the location and orientation of the patellar FHA both in vivo and non-invasively at various flexion angles and to relate the FHA to the trans-epicondyle axis (TEA).Methods: The Magnetic resonance (MR) images of 18 unilateral knees were collected at full extension and at 30°, 60°, 90°, and maximum angle of knee flexion. Three-dimensional models of knee joint at different flexion angles were developed with the MR images, and were used to calculate the patellar tracking and FHA with a spline interpolation algorithm. By using a coordinate system based on the TEA, the FHA tracking was quantified. Six parameters concerning the location and orientation of the patellar FHA were analyzed.Results: The average patellar FHA of 18 knees drew an L-shaped tracking on the midsagittal plane moving from the posteroinferior side of the TEA to the anterosuperior with knee flexion. Before 90° flexion, the patellar rotational radius decreased slightly, with an average value of 5.65 ± 1.09 cm. During 20° to 90° knee flexion, the average angle between the patellar FHA and TEA was approximately 10° and that between the FHA and coronal plane was maintained at about 0°, while that between the FHA and level plane fluctuated between -10° and 10°.Conclusions: Patellar FHA was not fixed during flexion, which showed a close relationship with femoral TEA in both location and orientation. The results could help us better understand the patellofemoral joint kinematics and further deal with troublesome patellofemoral disorders.

EFFECTS OF SIMULATED FIXED FEMORAL ROTATION ON THE PATELLOFEMORAL JOINT: IN VITRO AND IN VIVO BIOMECHANICAL ASSESSMENT IN CANINES

2000 ◽  
Vol 04 (02) ◽  
pp. 97-105 ◽  
Author(s):  
Thay Q Lee ◽  
Michele M. Schulz ◽  
Patrick J. McMahon
Keyword(s):  
Knee Flexion ◽  
Patellofemoral Joint ◽  
In Vitro Study ◽  
Femoral Rotation ◽  
Rotational Deformity ◽  
Biomechanical Assessment ◽  
Biomechanical Evaluation ◽  
Contact Pressures

The quantitative effects of fixed femoral rotation on the patellofemoral joint were assessed in canines in vitro and in vivo. For the in vitro study, ten canine knees were examined in neutral and 30 degrees of internal and external fixed femoral rotations. Fuji film was inserted into the patellofemoral joint and quadriceps loading was simulated at 60 and 90 degrees of knee flexion. There was significant increase in patellofemoral contact pressures on the contralateral facets of the patella with 30 degrees of fixed femoral rotation at both knee flexion angles (p < 0.05). For the in vivo study, 12 skeletally mature mongrel dogs were subjected to either internal or external bilateral femoral rotational deformity of 30 degrees. Three animals served as controls. Biomechanical evaluation of the articular cartilage showed a statistically significant decrease for both the unrelaxed and relaxed apparent shear modulus at six months for both internal and external femoral rotations (p < 0.05) in comparison to the control. In vivo results from fixed femoral rotation on the patellofemoral joint correlate with that expected from in vitro biomechanical results. The results from this study suggest that rotational deformity of the femur should be corrected within six months to prevent patellofemoral joint arthrosis.

In-vivo determination of patellofemoral joint contact pressures

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

In vivo quantification of the cat patellofemoral joint contact stresses and areas

1995 ◽  
Vol 28 (8) ◽  
pp. 977-983 ◽  
Author(s):  
Janet L. Ronsky ◽  
Walter Herzog ◽  
Thomas D. Brown ◽  
Douglas R. Pedersen ◽  
Edward S. Grood ◽  
...  
Keyword(s):  
Patellofemoral Joint ◽  
Contact Stresses ◽  
Joint Contact

scholarly journals Patellofemoral joint contact forces during activities with high knee flexion

2011 ◽  
Vol 30 (3) ◽  
pp. 408-415 ◽  
Author(s):  
Adam Trepczynski ◽  
Ines Kutzner ◽  
Evgenios Kornaropoulos ◽  
William R. Taylor ◽  
Georg N. Duda ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Patellofemoral Joint ◽  
Contact Forces ◽  
Joint Contact
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