A comparison of four models of total kneereplacementprostheses. J Bone Joint Surg [Am] 58-A:754-765 on ResearchGate, the professional network for scientists.... The unicondylar prosthesis was used in the mildest cases and gave the l...
"When I asked patients who had recently undergone the Oxford knee replacement, and who had had the experience of a total knee, or even a unicompartmental arthroplasty on the other knee to compare the surgeries, their response was: 'There is simply no comparison ...
What Are the Different Types of Prosthetics
A Comparison of Four Models of Total Knee-ReplacementProsthesesKneeFemur HeadPatellaKnee JointHumans...The unicondylar prosthesis was used in the mildest cases and gave the least complications, but the quality of results ...In all ty...
In the knee, prosthetic implants ..
There are many orthopedic manufacturing companies that produce different implants used in . Most of these companies make several different knee replacement prosthetic implants. Is there a way to determine which implant is best?
The Walldius hinge arthroplasty
While this new system of knee replacement has been available in Europe for a decade, this unicompartmental knee was approved by the FDA just over a year ago," said Dr.
used to secure the prosthesis on eight ..
Unlike total knee surgery that replaces all the knee joint surfaces, the Oxford knee resurfaces only the most severely affected part of the knee.
be offered as an alternative to primary arthrodesis of the knee.
The primary objective of this study is to distinguish between mobile bearing and fixed bearing posterior stabilized knee prostheses in the mechanics performance using the finite element simulation. Quantifying the relative mechanics attributes and survivorship between the mobile bearing and the fixed bearing prosthesis remains in investigation among researchers. In the present study, 3-dimensional computational model of a clinically used mobile bearing PS type knee prosthesis was utilized to develop a finite element and dynamic simulation model. Combination of displacement and force driven knee motion was adapted to simulate a flexion motion from 0° to 135° with neutral, 10°, and 20° internal tibial rotation to represent deep knee bending. Introduction of the secondary moving articulation in the mobile bearing knee prosthesis has been found to maintain relatively low shear stress during deep knee motion with tibial rotation.
inspite of a successful implantation of a Walldius prosthesis
Wear and delamination of PE insert are among the most common problems in TKA that limit the survivorship of the prostheses. This defect is generated by excessive shear stress, contact pressure, and cross-shear associated with tibiofemoral contact geometry [, ]. Lower contact area in less conforming TKA results in higher contact pressure and shear stress relative to high conformity TKA. During femoral rollback, tibiofemoral contact shifts from larger contact area at centre of condylar to smaller contact area at posterior sides of both medial and lateral condyles leading to increasing shear stress with increasing flexion angle. Comparable mechanism happens in both mobile and fixed bearing TKAs as shown in . As the knee flexes, medial femoral condylar moves anteriorly and lateral femoral condylar moves posteriorly causing internal rotation of tibia. Larger anterior surface relative to posterior on both tibia condyles leads to higher shear stress created at lateral condylar during deep bending motion. For fixed bearing condition, tremendous increment of shear stress at higher flexion angle (90°−110°) occurred due to impingement between femoral component and posterior articular surface of lateral condylar.