The tibial component of current knee prostheses made of ultra high molecular weight polyethylene (UHMWPE) has a high degree of wear that causes knee inflammation, prosthesis loosening and subsequent replacement in not more than 15 years. In order to know which UHMWPE material properties have more influence on wear, a steady state lubrication model with non-Newtonian synovial fluid has been studied through numerical solution. The results show that UHMWPE has a very high elastic modulus that makes difficult a well lubricated artificial joint and induces the formation of very thin lubricating films between the moving surfaces with the same magnitude of roughness components. This study shows that the use of deformable porous materials in the tibial component could cause the lubricating film thickness to be higher than the average roughness and the pressure levels to be lower than the one predicted for UHMWPE. These two facts imply friction and wear reduction.
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http://dx.doi.org/10.1080/10255840500523139 | DOI Listing |
J Arthroplasty
January 2025
Department of Orthopaedic Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, California.
Introduction: The two-stage surgical protocols used for the treatment of periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) are associated with marked patient morbidity. As such, alternatives such as durable "1.5-stage" spacer constructs have gained popularity.
View Article and Find Full Text PDFFront Bioeng Biotechnol
January 2025
Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany.
Introduction: Anterior knee pain and other patello-femoral (PF) complications frequently limit the success of total knee arthroplasty as the final treatment of end stage osteoarthritis. However, knowledge about the loading conditions at the PF joint remains limited, as no direct measurements are available. We hypothesised that the external knee flexion moment (EFM) is highly predictive of the PF contact forces during activities with substantial flexion of the loaded knee.
View Article and Find Full Text PDFJ Exp Orthop
January 2025
Department of Orthopaedic Surgery, Faculty of Medicine The University of Tokyo Tokyo Japan.
Purpose: To clarify the influence of biomechanics on post-operative clinical outcomes in bicruciate-retaining total knee arthroplasty (BCR-TKA).
Methods: Severe medial osteoarthritis who underwent BCR-TKA were examined. Each patient was asked to perform a squat (weight-bearing [WB]) and active assisted knee flexion (non-WB [NWB]) under single fluoroscopy surveillance.
Cureus
December 2024
Department of Health Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, JPN.
Purpose The infrapatellar fat pad (IFP) has the lowest pain threshold among all knee joint components and causes anterior knee pain after knee arthroplasty. It has been reported that selective muscle atrophy of the vastus medialis (VM) and fibrosis of the IFP may develop following knee joint surgery. Ultrasound enables visualization of IFP deformation (A1) from within the joint to the proximal area in response to muscle contraction, and this may be helpful in developing preventive and therapeutic strategies for IFP fibrosis.
View Article and Find Full Text PDFJ Arthroplasty
January 2025
Georgetown University School of Medicine, MedStar Georgetown University Hospital, Washington, D.C, USA. Electronic address:
Introduction: As the number of revision total knee arthroplasties (rTKA) continues to rise, there is increasing interest in the use of contemporary rotating hinge prostheses. These devices often incorporate porous cones to fill bone defects and enhance long-term fixation. This study evaluated the clinical and functional outcomes and survivorship in rTKA patients utilizing a rotating hinge prosthesis with flexible titanium (FT) cones, porous tantalum (PT) cones, or no cones.
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