scholarly journals Lateral facetectomy decreased patellofemoral contact pressure in total knee replacement: A cadaveric study

2017 ◽  
Vol 8 (1) ◽  
pp. 82-84 ◽  
Author(s):  
Varah Yuenyongviwat ◽  
Khanin Iamthanaporn ◽  
Theerawit Hongnaparak
Keyword(s):  
Total Knee Replacement ◽  
Contact Pressure ◽  
Knee Replacement ◽  
Cadaveric Study ◽  
Patellofemoral Contact Pressure ◽  
Total Knee

Effect of rotational prosthetic alignment variation on tibiofemoral contact pressure distribution and joint kinematics in total knee replacement

2017 ◽  
Vol 231 (11) ◽  
pp. 1034-1047 ◽  
Author(s):  
Xin Xie ◽  
Roy Rusly ◽  
John D DesJardins ◽  
Frank Voss ◽  
Kim Chillag ◽  
...  
Keyword(s):  
Total Knee Replacement ◽  
Contact Pressure ◽  
Knee Replacement ◽  
External Rotation ◽  
Tibial Slope ◽  
Fe Model ◽  
Posterior Tibial ◽  
Pressure Concentration ◽  
Total Knee

In total knee replacement surgery, implant alignment is one of the most important criteria for successful long-term clinical outcome. During total knee replacement implantation, femoral and tibial alignment are determined through appropriate bone resections, which could vary based on patient anatomy, implant design and surgical technique and further influence loading conditions and clinical outcomes. The current research focused on three critical alignment parameters for total knee replacement insertion: femoral component internal/external (I/E) rotation, varus–valgus tibiofemoral angulation and posterior tibial slope. A computational finite element model of total knee replacement implant was developed and validated comparing with kinematic outputs generated from experimentally simulated knee joint motion. The FE model was then used to assess 12 different alignment scenarios based on previous case reports. Postoperative knee kinematics and joint contact pressure during simulated gait motion were assessed. According to the parametric study, FE model cases with femoral rotation revealed extra tibial I/E rotation in the predefined direction but negligible change in tibial anterior–posterior translation; cases with increased tibial slope showed notably increased tibial external rotation and anterior translation; cases with varus tibiofemoral angle presented slightly more tibial external rotation, whereas cases with valgus angle presented an observable increase in tibial internal rotation at the middle phase of the gait cycle. Finally, the response surface obtained from the postprocessing study demonstrated good statistical correlation with existing case study results, providing reliable estimation of peak tibiofemoral contact pressure affected by combinations of alignment parameters. The observations indicate that femoral external alignment should be favored clinically for enhanced patellar tracking and reduced contact pressure concentration for better long-term performance. Posterior tibial slope enables deep knee flexion. Extra femoral internal rotation as well as tibiofemoral varus–valgus alignment could be avoided in surgery due to deficiency in patellar tracking and high pressure concentration.

Computational Wear Prediction for Impact of Kinematics Boundary Conditions on Wear of Total Knee Replacement Using Two Cross-Shear Models

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Jing Zhang ◽  
Zhenxian Chen ◽  
Yongchang Gao ◽  
Xuan Zhang ◽  
Lei Guo ◽  
...  
Keyword(s):  
Total Knee Replacement ◽  
Contact Pressure ◽  
Knee Replacement ◽  
External Rotation ◽  
Posterior Translation ◽  
Total Knee ◽  
Dependent Model ◽  
Pressure Independent ◽  
Anterior Posterior ◽  
Independent Model

Abstract Wear particle-induced osteolysis is the main reason for the long-term failure of total knee replacement. Simulator testing is the standard procedure for validating wear performance pre-clinically. The load and kinematics specified in the International Organization for Standardization (ISO) are standard input profiles for wear testing of implants. Directions of internal–external (IE) rotation and anterior–posterior (AP) translation have been modified in the new version of ISO 14243-3 2014. This study focused on investigating the effects of internal–external rotation and anterior–posterior translation on the wear of knee implants. Numerical wear prediction was performed using the finite element model along with two wear models, namely the contact pressure independent model and contact pressure dependent model. Addition of internal–external rotation significantly increased the wear, and the two wear models obtained similar results. The effect of internal–external rotation direction on wear was slight. Forward movement of the tibial insert during flexion decreased the wear under the contact pressure independent model and increased the wear under the contact pressure dependent model. When the AP direction switched, the two models obtained opposite wear tendencies. The results predicted by the contact pressure dependent model were consistent with those of wear tendency experiments reported in the literature. Further investigation of wear physical principles was necessary to gain a more reliable model. This study demonstrated that both internal–external rotation and anterior–posterior translation were pivotal factors influencing the contact mechanism and wear of total knee implants. More realistic kinematics are necessary for accurate wear assessment.

Effect of Malalignment and Friction on Contact Pressure in the Polyethylene Component in the Total Knee Replacement

2002 ◽  
Author(s):  
Nagarajan Chandran ◽  
F. Amirouche ◽  
Wayne Goldstein ◽  
Riad Barmada
Keyword(s):  
Total Knee Replacement ◽  
Pressure Distribution ◽  
Contact Pressure ◽  
Knee Replacement ◽  
Contact Surface ◽  
Tibial Component ◽  
Loading Condition ◽  
Experimental Results ◽  
Component Rotation ◽  
Total Knee

The articulation of the femoral and tibial component contact surface is influenced by the alignment of these components. Malalignment of the total knee is perceived to increase the contact pressure and reduces the life of the polyethylene component. In this paper the contact pressure obtained from a experimental results [2] are used as the loading condition for a normal TKA alignment. In the case of a malalignment, we assumed that the loads at the interface do not change and the malalignment is to the femur component rotation. The results show that the pressure distribution is higher in the malaligned fit, which implies a reduced lifetime for the TKA. In the analysis, the experimental loads derived from cadaver knee testing are increased by a scale factor of 5, 10, 20, 50 to predict a more realistic loading condition of the knee. The effect of malrotation on the pressure distribution under these condition shows that the percentage change in the pressure distribution is slightly larger than that from the experimental loads.

scholarly journals Anatomy of posterior cruciate ligament retained in a posterior cruciate ligament retaining total knee replacement: a cadaveric study

SICOT-J ◽  
2018 ◽  
Vol 4 ◽  
pp. 40
Author(s):  
Tarun Goyal ◽  
Mukesh Singla ◽  
Souvik Paul
Keyword(s):  
Total Knee Replacement ◽  
Posterior Cruciate Ligament ◽  
Knee Replacement ◽  
Soft Tissues ◽  
Cruciate Ligament ◽  
Cadaveric Study ◽  
Replacement Surgery ◽  
Before And After ◽  
Total Knee ◽  
Femoral Side

Background: Recent evidence has highlighted a risk that the majority of posterior cruciate ligament (PCL) is removed while making bone cuts in tibia and femur during total knee replacement surgery. Aim of this cadaveric study is to calculate how much PCL footprint is retained in a PCL retaining prosthesis after routine tibial and femoral cuts are made.  Methods: Twelve paired formalin-fixed Indian cadaveric knees were studied. Knees were disarticulated and all soft tissues were circumferentially removed from the tibia and femur. Footprints of antero-lateral and postero-medial bundles were marked on tibia and femur. Proximal tibial and distal femoral cuts were made using standard cutting jigs (Zimmer NexGen LPS). Digital photographs were taken with a magnification marker attached on the bone before and after making the cuts. Area of PCL insertion before and after the bone cuts was measured using software ImageJ (National Institute of Health). Results: Footprint on tibial side was reduced by 9.1%, and on femoral side by 21.8%. Footprint of AL bundle was reduced by 24.3% on the tibial side and by 15.3% on the femoral side. Footprint of PM bundle on tibia was not affected by the bone cut but was reduced by 18.5% on the femoral side. Conclusion: Tibial and femoral insertions of PCL are relatively well preserved after bone cuts are made in a posterior cruciate retaining TKR. There is differential sectioning of antero-lateral and postero-medial bundles of PCL on tibial and femoral sides.

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