scholarly journals Traumatic Dislodgement of Tibial Polyethylene Insert after a High-Flex Posterior-Stabilized Total Knee Replacement

2015 ◽  
Vol 2015 ◽  
pp. 1-4
Author(s):  
Juan Felix Astoul Bonorino ◽  
Pablo Ariel Isidoro Slullitel ◽  
Gonzalo Rodrigo Kido ◽  
Santiago Bongiovanni ◽  
Renato Vestri ◽  
...  
Keyword(s):  
Total Knee Replacement ◽  
Knee Replacement ◽  
Mobile Bearing ◽  
Polyethylene Insert ◽  
Fixed Bearing ◽  
Posterior Stabilized ◽  
Cruciate Retaining ◽  
Tibial Insert ◽  
Total Knee ◽  
Similarities And Differences

Many pathologic entities can produce a painful total knee replacement (TKR) that may lead to potential prosthetic failure. Polyethylene insert dissociation from the tibial baseplate has been described most frequently after mobile-bearing and cruciate-retaining TKRs. However, only 3 tibial insert dislocations in primary fixed-bearing High-Flex posterior-stabilized TKRs have been reported. We present a new case of tibial insert dislocation in a High-Flex model that shares similarities and differences with the cases reported, facilitating the analysis of the potential causes, which still remain undefined.

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.

Effects of interference assembly of a tibial insert on the tibiofemoral contact mechanics in total knee replacement

2019 ◽  
Vol 233 (9) ◽  
pp. 948-953 ◽  
Author(s):  
Zhenxian Chen ◽  
Jing Zhang ◽  
Yongchang Gao ◽  
Shibin Chen ◽  
Xuan Zhang ◽  
...  
Keyword(s):  
Total Knee Replacement ◽  
Contact Mechanics ◽  
Knee Replacement ◽  
Articular Surface ◽  
Peak Load ◽  
Element Model ◽  
Fixed Bearing ◽  
Locking Mechanism ◽  
Tibial Insert ◽  
Total Knee

Tibial locking mechanism design is adopted to limit the backside micromotion in fixed-bearing total knee replacement. However, the effect of the interference assembly of a tibial insert on the tibiofemoral contact mechanics was usually ignored. Finite element model of a fixed-bearing total knee replacement with full peripheral locking mechanism was established to simulate the interference assembly of the tibial insert, and the corresponding effects on the tibiofemoral contact mechanics were predicted. Due to the interference assembly of the tibial insert, a maximum Mises stress of 3.24 MPa was found for the tibial insert before loading. Furthermore, the contact stress was increased by 8.77%, and the contact area was decreased by 5.43% under peak load. The interference assembly of the tibial insert in a fixed-bearing total knee replacement changed the tibiofemoral contact mechanics. This study indicated that the level of interference fit should be cautiously designed for the tibial locking mechanism in fixed-bearing total knee replacement for balancing the articular surface wear and the backside wear of the modular tibial insert.

Change in Knee Passive Envelope of Motion With Total Knee Replacement Design

2008 ◽  
Author(s):  
Amit M. Mane ◽  
Chadd W. Clary ◽  
Amber N. Reeve ◽  
Lorin P. Maletsky ◽  
Kevin A. Dodd
Keyword(s):  
Total Knee Replacement ◽  
Knee Replacement ◽  
Experimental Research ◽  
Natural Condition ◽  
Clinical Practices ◽  
Posterior Stabilized ◽  
Cruciate Retaining ◽  
Replacement Surgery ◽  
Total Knee ◽  
Replacement Design

Many researchers have studied the tibial passive motion, the boundaries of which are defined by various knee ligamentious and bony constraints [1, 2, 3]. The technique has been used in clinical practices and experimental research to assess injury and predict likely surgical outcomes [1, 2]. After total knee replacement surgery (TKR), the implants’ design features and altered ligamentious tension provide the joint constraint and stability. Therefore, the change in passive envelope of motion from the natural condition could be used to observe the altered constraints and stability achieved in TKR knees. The objective of this study was to assess the change in passive envelope of motion after TKR with two implant designs: cruciate retaining and posterior stabilized.

scholarly journals The mid term functional outcomes of NexGen legacy posterior stabilized flex fixed bearing total knee replacement in primary osteoarthritis

2016 ◽  
Vol 15 (1) ◽  
Author(s):  
Ed Simor Khan Mor Japar Khan ◽  
Rizal Abdul Rani ◽  
Mohd Ashraff Mohd Ariff ◽  
Khairul Nizam Siron@Baharom ◽  
Mohd Shahidan Noor Rahin ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Total Knee Replacement ◽  
Knee Replacement ◽  
Functional Outcomes ◽  
Fixed Bearing ◽  
Posterior Stabilized ◽  
Primary Osteoarthritis ◽  
Sf 36 ◽  
Total Knee

Introduction: To evaluate the midterm functional outcomes of patients who had undergone total knee replacement (TKR) using posterior stabilized (PS) fixed bearing system from January 2005 until April 2006 for primary osteoarthritis of the knees. Methods: A retrospective study was done on forty-six patients, 87% female (n= 40) and 13% male (n=6), aged 54 to 81 years old (mean 69 ± 5.69) who had undergone primary TKR using the NexGen LPS-Flex Zimmer Warsaw. The patients were followed up for at least five years. A medial parapatellar approach and cemented posterior stabilized fixed bearing TKR system were used performed by one of two arthroplasty surgeons. All patients followed the same rehabilitation protocol post-operatively. Assessments were done using Oxford-12 knee scoring questionnaire to evaluate knee function and SF-36 to assess quality of life outcomes. Results: Oxford knee score revealed patients had lower (better) than average scores in terms of function (score 14.35 ± 4.21 out of 35) and pain (score 9.28 ± 3.01 out of 25). Analysis on the quality of life outcome score with SF-36 revealed a higher (better) score for mental component summary (MCS) relative to physical component summary (PCS). Patients had the highest score for role emotional (RE), followed by mental health (MH), and social functioning (SF). Conclusions: The NexGen LPS-Flex TKR produced a good functional outcome with minimal pain in the operated knee with better mental compared to physical health of patients in the midterm period post-total knee replacement.

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