A Finite-Element Study of Metal Backing and Tibial Resection Depth in a Composite Tibia Following Total Knee Arthroplasty

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Susumu Tokunaga ◽  
Renee D. Rogge ◽  
Scott R. Small ◽  
Michael E. Berend ◽  
Merrill A. Ritter

Prosthetic alignment, patient characteristics, and implant design are all factors in long-term survival of total knee arthroplasty (TKA), yet the level at which each of these factors contribute to implant loosening has not been fully described. Prior clinical and biomechanical studies have indicated tibial overload as a cause of early TKA revision. The purpose of this study was to determine the relationship between tibial component design and bone resection on tibial loading. Finite-element analysis (FEA) was performed after simulated implantation of metal backed (MB) and all-polyethylene (AP) TKA components in 5 and 15 mm of tibial resection into a validated intact tibia model. Proximal tibial strains significantly increased between 13% and 199% when implanted with AP components (p < 0.05). Strain significantly increased between 12% and 209% in the posterior tibial compartment with increased bone resection (p < 0.05). This study indicates elevated strains in AP implanted tibias across the entirety of the proximal tibial cortex, as well as a posterior shift in tibial loading in instances of increased resection depth. These results are consistent with trends observed in prior biomechanical studies and may associate the documented device history of tibial collapse in AP components with increased bone strain and overload beneath the prosthesis.

2021 ◽  
Vol 15 (1) ◽  
pp. 17-21
Author(s):  
Takehiko Sugita ◽  
Naohisa Miyatake ◽  
Seiya Miyamoto ◽  
Akira Sasaki ◽  
Ikuo Maeda ◽  
...  

The tibial resection depth during total knee arthroplasty for valgus knees has been variously described and not been standardized yet. Accordingly, it has been proposed in this article, that the sulcus between the medial and lateral intercondylar tibial tubercles can be used as a reference point for the tibial resection depth. The resection can be performed 8 to 9 mm distal to the sulcus.


2018 ◽  
Vol 225 ◽  
pp. 03009 ◽  
Author(s):  
N.M.A. Azam ◽  
Rosdi Daud ◽  
H. Mas Ayu ◽  
J. Ramli ◽  
M.F.B. Hassan ◽  
...  

The effect of flexion angle on contact stress of the knee joint still open to the debate since lack of proof shown that flexion angles does effect the contact stress of Total Knee Arthroplasty (TKA). Thus the aim of this study is to investigate the effect of different flexion angle on contact stress of TKA via finite element method. The TKA is simulated using ANSYS Workbench and the applied loads are 2200 N, 3200 N and 2800 N. The Finite element Analysis (FEA) results for maximum stress of current and proposed designed were then compared. For the new proposed design, the maximum stress for 15° is 12.2 MPa, 45° is 23.6 MPa and 60° is 22.5 MPa which is lower than current design. Thus, it can be concluded that the new proposed design better than current design in term of contact stress. While, the different flexion angle do gives an impact on the performance of the TKA.


Author(s):  
Eric Rohrs ◽  
Manish Paliwal ◽  
D. Gordon Allan

Aseptic loosening of the tibial implant is one of the major reasons of failure in Total Knee Arthroplasty (TKA). The cement viscosity at the time of application to the bone influences the cement penetration and stability of the prosthesis. Four cements of different viscosities and set times were selected for analysis (Simplex-P, DePuy-2, Palacos, and Endurance). Finite element analysis was used to model cement flow and cement mantle resulting from a surgically implanted tibial plate into sawbone open cell blocks simulating tibial cancellous bone (Pacific Research, WA). Frictional stress, pressure, sliding distance, and total stress at the bone-cement-stem interface were studied at the contact interfaces, which may contribute towards construct stability. Palacos had the maximum interface pressure, sliding distance, and total stress, while DePuy-2 displayed the lowest total stress and sliding distance at interface. Simulated flow profile correlated well with the cemented constructs’ radiographic profiles.


2019 ◽  
Author(s):  
Yeran Li ◽  
Yuhang Gao ◽  
Lu Ding ◽  
Chen Yang ◽  
Jinlong Wang ◽  
...  

Abstract BackgroundThis study aimed to determine the longest usable range of tibial prosthesis extension stems in Chinese patients undergoing primary total knee arthroplasty and to analyze the effect of different stem lengths on prosthesis stability within this range.MethodsWe conducted three-dimensional modeling and simulated surgery in patients with genu varum to measure the longest usable range of tibial prothesis stems, identify impinged cortices under tibial posterior slope cut of 0° and 3°, and analyze factors influencing the longest stem length. We built finite element models according to the longest usable range of extension stems to simulate tibial prostheses with different stem lengths, measure the stress distribution of tibias and prostheses and the relative displacement of distal ends of prostheses, and investigate the effect of different stem extension lengths on prosthesis stability.ResultsWe simulated osteotomy with a tibial posterior slope cut of 0° and 3°, under which the maximum tibial prosthesis stem length was 83 mm (79±24 mm). The simulated tibial cut with a tibial posterior slope of 3° indicated the maximum tibial prosthesis stem length to be 83 mm (83±20 mm). According to the longest usable range of extension stems, we defined five groups for finite element analysis with 40-mm, 50-mm, 60-mm, 70-mm, and 80-mm stem lengths and analyzed each group for posterior slopes of 0° and 3°. The 80-mm stem length models showed minimum relative displacement of the distal end of tibial prosthesis (0°: 2.63, 1.61±0.05 µm; 3°: 1.48, 1.44±0.09 µm), whereas the 40-mm stem length models showed maximum relative displacement (0°: 3.16, 3.19±0.12 µm; 3°: 1.84, 1.81±0.07 µm). As the length of tibial prosthesis stems increased from 40 to 70 mm, the relative displacement of the distal end of prosthesis decreased for both posterior slopes but was insignificant when stem lengths increased to 70–80 mm.ConclusionsBased on the results, we suggest that using the longest tibial stem is not always necessarily a better option to increase stability, as the prosthesis shows greater stability in only a specific range of increased length but shows insignificant change when the length is greatly increased.


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