| Background:Total knee arthroplasty is an effective and durable treatment for end-stage knee osteoarthritis.The primary goals of total knee arthroplasty include reducing knee pain,realigning the femur and tibia,and maintaining knee stability and joint flexibility.Currently,prosthetic loosening is the second most common cause of surgical failure and revision after infection.Poor prosthesis positioning,which allows for uneven load distribution and stress concentration,leading to wear of the polyethylene liner,is a major factor in prosthesis loosening.The problems caused by misalignment of the tibial plateau prosthesis in the medial and lateral planes are unknown.Finite element analysis is the simulation of real physical systems using numerical approximations,a numerical technique that allows the simulation of complex geometries and loading systems.In particular,it can be used in total knee arthroplasty to compare implant materials and optimize implant parameters,thereby reducing wear rates.In addition,finite element analysis can be used to test different misalignments using simulated angles,friction and stresses in order to apply these findings to preoperative planning and prevent the risk of potential surgical failure,and has been widely used in the field of orthopedics.This study aimed to investigate the stress distribution and micro-movement of the tibia when the tibial plateau prosthesis is translated 1 mm and 2 mm medially and laterally,respectively,using finite element analysis.The biomechanical analysis is used to optimize the design,screening,surgical prediction and efficacy of the prosthesis in total knee arthroplasty.Method:1.a non-homogeneous tibial model was created from the patient’s CT data scan.2.Simulating the surgical procedure,the tibial model was excised in the traditional surgical manner,preserving the proximal portion of the tibia,and all prosthetic models were mounted and divided into five groups according to the tibial plateau prosthesis in five different positions:Lateral-2 mm;Lateral-1 mm;Medium;Medial-2 mm;and Medial-1 mm.3.Simulate the loading conditions of the misaligned prosthesis during the standing of both legs and impose them.And finite element analysis was performed for each of the five groups of models to obtain the stress,stress distribution and micro-movement of the proximal tibia when the tibial plateau prosthesis was in five different positions.Result:The maximum stress in the five groups with different misalignments of the platform was 47.29 MPa(Lateral-2 mm).The maximum stress distribution in the seven regions of the proximal tibia was 1.43 MPa,occurring at(Medial-2 mm),while the minimum stress was 0.075 MPa,occurring when the prosthesis was in an intermediate position.The red part of the high stress was concentrated in the lower part of the proximal tibia.In the path of the rod cavity boundary,the maximum stress of 6.43 MPa occurred at 25-50 mm(Lateral-2 mm).The maximum micromotion among the five groups in different positions was 7.215 μm(Lateral-2mm).The platform was subjected to greater micromotion than the stem,and the maximum micromotion of 3.854 um occurred when the platform was misaligned 1 mm to the inside.Conclusion:When placing the tibial plateau prosthesis during total knee arthroplasty,an error of 2 mm or less is acceptable as long as it does not overhang. |
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