Publications by authors named "Yusuke Yamawaki"
Article Synopsis
- A study explored the use of an anatomical artificial bone implant for improving alignment during open-wedge high tibial osteotomy by analyzing the shape of the osteotomy surface and assessing its effectiveness in achieving precise corrections.
- Using virtual simulations and cadaver tests, researchers created a 10° correction angle implant and compared its accuracy in maintaining posterior tibial slope and rotation against conventional wedge-shaped spacers in real-life surgeries.
- Results showed that the anatomical implant had high contour compatibility and minimal changes in tibial alignment, effectively reducing errors in correction angles compared to traditional methods.
Background: Medial soft tissue release is occasionally performed to achieve mediolateral ligament balance in total knee arthroplasty (TKA), whose sequential effect on mediolateral and anteroposterior stability remains unclear. This study aimed to quantitatively evaluate the difference in mediolateral and anteroposterior stability according to a sequential medial soft tissue release in TKA.
Methods: Cruciate-retaining TKA was performed in six cadaveric knees.
Purpose: The degree to which varus knees can be corrected manually is important when considering total versus unicompartmental knee arthroplasty (UKA). The primary aim was to clarify the relationship between the degree of coronal alignment correction and radiographic parameters involved in UKA prognosis using preoperative full-length lower extremity valgus stress radiography. The secondary aim was to identify the factors affecting alignment correction.
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- - This study compares single-radius and multi-radius designs in total knee arthroplasty to see how they affect knee movement and ligament forces during activities like squatting and walking.
- - In computer simulations, the multi-radius design showed significant anterior translation of the femur, resulting in decreased tension in the medial collateral ligament during early flexion, while the single-radius model maintained consistent ligament tension.
- - The findings suggest that choosing a single-radius design may help prevent mid-flexion instability by offering more stability and less movement of the femur compared to the multi-radius model.
Background: Patellofemoral arthroplasty (PFA) is reported to provide nearly normal PF joint kinematics but only with adequate surgical techniques. This study evaluated the effects of various femoral component settings on patellar component biomechanics.
Methods: A dynamic musculoskeletal computer simulation analyzed normal knee and standard PFA models, as well as 8 femoral component malposition models: 5° internal or external rotation, 5° valgus or varus, 5° extension or flexion, and 3-mm or 5-mm anterior positioning.
Purpose: This study evaluated the clinical outcomes of medial open-wedge high tibial osteotomy (MOWHTO) and bone marrow lesion (BML) scores and volumes. The hypotheses were that quantitative BML volume is more associated with clinical outcomes of MOWHTO than qualitative BML evaluations, and pre-operative BML volume is associated with the improvement of clinical outcomes.
Methods: Patients who underwent MOWHTO were retrospectively enrolled.
Purpose: The primary aim of this study was to evaluate the 3-dimensional morphology of the proximal tibia around the osteotomy plane in open-wedge high tibial osteotomy, focusing on the posterolateral (PL) and posteromedial (PM) tibial condyles, and to clarify the changes in morphologic parameters due to differences in patient characteristics and hinge position. The secondary aim was to examine whether morphologic features were associated with insufficient osteotomy, which increases the risk of lateral hinge fracture (LHF).
Methods: The PL and PM anteroposterior distance, asymmetry ratio, and discrepancy between PL and PM distances along the tibial osteotomy plane were measured.
The correlation between static and dynamic mediolateral (ML) tilts of the joint line in the coronal plane remains unknown after total knee arthroplasty (TKA). The purpose was to evaluate the ML tilt as measured by two-dimensional to three-dimensional registration during stair ascent in TKA patients, and to examine the correlation between the dynamic ML tilt and radiographic measurements of static indices. Thirty-two knees that underwent TKA using the mechanical alignment method were included.
View Article and Find Full Text PDFSeveral concepts may be used to restore normal knee kinematics after total knee arthroplasty. One is a kinematically aligned (KA) technique, which restores the native joint line and limb alignment, and the other is the use of a medial pivot knee (MPK) design, with a ball and socket joint in the medial compartment. This study aimed to compare motions, contact forces, and contact stress between mechanically aligned (MA) and KA (medial tilt 3° [KA3] and 5° [KA5]) models in MPK.
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