Polyethylene Wear in Mobile-Bearing Prostheses

Orthopedics ◽  
2002 ◽  
Vol 25 (2) ◽  
Author(s):  
Douglas J Kilgus
Keyword(s):  
Polyethylene Wear ◽  
Mobile Bearing

Mobility and Stability of the Intact and Replaced Knee

2015 ◽  
Author(s):  
John Goodfellow ◽  
John O'Connor ◽  
Hemant Pandit ◽  
Christopher Dodd ◽  
David Murray
Keyword(s):  
Total Knee Replacement ◽  
Knee Replacement ◽  
Final Section ◽  
Sagittal Plane ◽  
Polyethylene Wear ◽  
Mobile Bearing ◽  
Theoretical Background ◽  
Cruciate Retaining ◽  
Prosthetic Knee ◽  
Total Knee

Having demonstrated in Chapter 2 that a fully conforming mobile bearing can minimise polyethylene wear, in this chapter we show that a mobile bearing prosthesis, unconstrained in the sagittal plane, can restore natural mobility and stability. For surgeon readers who are less interested in the theoretical background, it might be advisable to go straight to Chapter 4, Indications, or to start by reading the final section of this chapter, The Loaded Prosthetic Knee. If that proves interesting, the surgeon might attempt The Unloaded Prosthetic Knee. For the more research minded surgeon or engineer, it seems more logical to start with the Unloaded Natural Knee (the longest section of the chapter) and to read from there. The chapter may also be of interest to those surgeons embarking on the use of a bi-cruciate retaining total knee replacement.

scholarly journals A Technical Tip to Avert Meniscal Rotation and Dislocation in a Mobile Bearing Unicompartmental Knee Arthroplasty

2020 ◽  
Vol 3 (1) ◽  
pp. 42-48
Author(s):  
Vijay Kumar ◽  
Mayur Nayak ◽  
Rajan Panthee ◽  
Rahul Yadav ◽  
Siddhartha Marendupaka
Keyword(s):  
Case Report ◽  
Surgical Technique ◽  
Blood Loss ◽  
Polyethylene Wear ◽  
Vertical Wall ◽  
Mobile Bearing ◽  
Common Complication ◽  
Unicondylar Knee Replacement ◽  
Tibial Cut ◽  
Bearing Dislocation

The Oxford (Oxford® partial knee; Biomet) mobile bearing medial unicondylar knee replacement (OUKR) is a preferred choice by surgeons due to minimal blood loss, reduced pain, and better range of motion. Commonly observed complications include aseptic loosening, polyethylene wear, bearing dislocation, and periprosthetic fractures. A bearing dislocation can be prevented by ensuring that there is correct tracking of bearing during the trial reduction as well as no loss of entrapment. We present a case report in a 50-year-old patient undergoing bilateral OUKR wherein it was observed that the meniscal bearing upon the flexion of the knee joint had the tendency to dislocate. Upon revising the vertical tibial recut according to the anterior superior iliac spine, the meniscus was found to have a normal excursion. Mobile bearing dislocation is a unique complication of mobile bearing OUKR. Surgical technique is of paramount importance in ensuring a successful OUKR. The vertical tibial cut is made to accommodate the vertical wall of the tibial component. Meniscal displacement is quite a common complication and can occur due to multiple causes. Inaccurate vertical tibial cut may be one such reason leading to tibial dislocation.

Impact of Articulation Geometry on Contact Mechanics in Total Ankle Replacement Design

2011 ◽  
Author(s):  
Mehul A. Dharia ◽  
Jeff E. Bischoff ◽  
Duane Gillard ◽  
Fred Wentorf ◽  
Matt Mroczkowski
Keyword(s):  
Lower Risk ◽  
First Generation ◽  
Polyethylene Wear ◽  
Mobile Bearing ◽  
Total Ankle Replacement ◽  
Fixed Bearing ◽  
Ankle Replacement ◽  
Improved Outcomes ◽  
Articulating Surface ◽  
Replacement Design

Total ankle replacement designs have evolved since their introduction in the mid 1970s. While the first-generation total ankle replacement (TAR) designs had unacceptably high failure rates, recent designs have demonstrated improved outcomes [1]. Two philosophies are commonly used in TAR design: mobile-bearing and fixed-bearing. Unlike mobile-bearing designs which have two articulating surfaces, fixed-bearing designs have only one articulating surface. While fixed-bearing designs have lower risk of dislocation than mobile-bearing designs, the single articulation feature can produce higher contact stress on the articulating surface, increasing the potential for polyethylene wear [1, 2].

Is there reduced polyethylene wear and longer survival when using a mobile-bearing design in total knee replacement?

2013 ◽  
Vol 95-B (8) ◽  
pp. 1057-1063 ◽  
Author(s):  
Y. Zeng ◽  
B. Shen ◽  
J. Yang ◽  
Z. K. Zhou ◽  
P. D. Kang ◽  
...  
Keyword(s):  
Total Knee Replacement ◽  
Knee Replacement ◽  
Polyethylene Wear ◽  
Mobile Bearing ◽  
Total Knee ◽  
Bearing Design

scholarly journals Polyethylene Bearing Wear in the Oxford Unicompartmental Knee

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Priyanka Ghosh ◽  
Hasan Mohammad ◽  
Stephen Mellon ◽  
David Murray
Keyword(s):  
Wear Rate ◽  
Polyethylene Wear ◽  
Oxford Knee Score ◽  
Knee Kinematics ◽  
Mobile Bearing ◽  
Unicompartmental Knee Replacement ◽  
Late Time ◽  
Unicompartmental Knee ◽  
Implant Size ◽  
Over Time

Background and Hypothesis: The Oxford Knee is a unicompartmental knee replacement (UKR) for patients with end-stage knee osteoarthritis (OA). It contains a polyethylene (PE) mobile bearing between the femoral and tibial components that helps maintain normal knee kinematics. Unfortunately bearing wear is one of the leading causes of UKR failure. In this study, we sought to investigate PE wear rate over time and the initial deformation (creep) in early months. Project Methods: This study used radiostereometric analysis (RSA) to precisely track polyethylene bearing thickness over time in 40 medial Oxford UKR patients. The patients underwent stereo radiographs at 1 week post-op (reference), 3 months, 6 months, 1 year, 2 years, and 5 years. Model-based RSA software was used to determine the exact position of the femoral and tibial components, and Matlab was used to calculate the minimum linear distance between these two components, taken as bearing thickness. Results: The average wear rate was 0.32mm/yr (SD 0.42) in the first 3 months, 0.16mm/yr (SD 0.55) from 3 to 6 months, and 0.07mm/yr (SD 0.03) between 1 and 5 years. No correlation was found between wear rate and BMI, fixation, implant size, or 5 year Oxford Knee Score. Conclusion and Potential Impact: This was the first study to investigate detailed early and late time points of polyethylene wear in the Oxford UKR. Mean bearing wear was higher in the first 6 months, presumably due to creep, and significantly reduced from 1 year onwards, presumably while true wear took place.

scholarly journals Late Failure of a Polyethylene Unicompartmental Knee Insert -Retrieval Analysis Protocol and Results

2022 ◽  
Vol 58 (4) ◽  
pp. 187-196
Author(s):  
Rodica Marinescu ◽  
Dan Laptoiu ◽  
Izabela-Cristina Stancu ◽  
Cristina Busuioc
Keyword(s):  
Polyethylene Wear ◽  
Traumatic Event ◽  
Mobile Bearing ◽  
Severe Wear ◽  
Retrieval Analysis ◽  
Unicompartmental Knee ◽  
Late Failure ◽  
Macroscopic Examination ◽  
Analysis Protocol

This study reports the investigation of a degraded polyethylene insert retrieved after the catastrophic failure of a mobile bearing knee implant, occurred after a traumatic event and leading to a late revision. Understanding wear mechanisms of polyethylene components is important to improve the implants for joint replacement. This model of unicompartmental arthroplasty, due to its mobile, congruent insert and design, has the potential to attain low rates of wear, leading to an improved survival of the prosthesis over fixed-bearing knee implants. During the surgical technique, however, it is critical to avoid any source of impingement or incongruent articulation, as this are associated with increased rates of polyethylene wear and may contribute to the early necessity for revision surgery. The investigated insert presented a macroscopic fragmentation, surface and bulk defects and debris. Characterization of the retrieved polyethylene implant fragments was performed by macroscopic examination, by scanning electron microscopy and Fourier transform infrared spectroscopy. Due to a systematic retrieval analysis according to current standards, we can question that, in our case, third body wear is rarely pure bone or pure cement debris related but a combination of the two mentioned. The combination enhanced contribution of polyethylene debris in severe wear initiation and progression. Complete examination of the explants exhibiting breakage or severe wear may help in understanding pathogenic ways of failure in unicompartmental knee.

Patellar Clunk Syndrome with Polyethylene Wear and Medial Synovial Hypertrophy after Mobile Bearing Total Knee Arthroplasty: A Case Report

2011 ◽  
Vol 17 (2) ◽  
pp. 131-133
Author(s):  
Soo Jae Yim ◽  
Mun Suk Jang ◽  
Joon Hee Yoon ◽  
Sang Hyok Lee ◽  
Hee kyung Kang
Keyword(s):  
Total Knee Arthroplasty ◽  
Case Report ◽  
Knee Arthroplasty ◽  
Polyethylene Wear ◽  
Mobile Bearing ◽  
Synovial Hypertrophy ◽  
Total Knee

Polyethylene wear of mobile-bearing unicompartmental knee replacement at 20 years

2011 ◽  
Vol 93-B (4) ◽  
pp. 470-475 ◽  
Author(s):  
B. J. L. Kendrick ◽  
D. J. Simpson ◽  
B. L. Kaptein ◽  
E. R. Valstar ◽  
H. S. Gill ◽  
...  
Keyword(s):  
Knee Replacement ◽  
Polyethylene Wear ◽  
Mobile Bearing ◽  
Unicompartmental Knee Replacement ◽  
Unicompartmental Knee
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