Subaortic stenosis (SAS) and ascending aortic dilatation (AAD) often coexist, and the transitional stage from normal to early lesions is critical for intervention, yet their synergistic effects on the tricuspid aortic valve (TAV) remain unclear. This study used a standardized 3D fluid-structure interaction model to simulate nine cases combining different transvalvular gradients and ascending aortic diameters, in order to analyze leaflet kinematics and hemodynamics. The results showed significant synergistic amplification of flow velocity and wall shear stress (WSS). In severe combined lesions, peak flow velocity increased by 144.8% and peak WSS exceeded the physiological threshold by 42%, leading to premature over-opening and asymmetric leaflet motion. A high-risk reference range was identified: ascending aortic diameter ≥30 mm with transvalvular gradient ≥22 mmHg. These findings reveal the mechanical injury mechanism of early combined lesions and provide theoretical references for risk screening and individualized intervention in SAS-AAD patients.
The biomechanical implications of coronal-plane alignment following paediatric anterior cruciate ligament reconstruction (ACLR) remain unclear. Five adolescents underwent gait analysis, magnetic resonance imaging, and electromyography-informed neuromusculoskeletal finite-element modelling 12 months post-ACLR. Subject-specific models incorporating measured hip-knee-ankle angle were compared with neutral alignment simulations under identical gait inputs. Coronal-plane alignment produced participant-specific differences in tibial cartilage stress magnitude, with stress patterns preserved (r ≥ 0.90). Tibiofemoral kinematics remained unchanged, without consistent relationships between alignment and medial-lateral stress distribution. These exploratory findings suggest limited biomechanical influence of coronal-plane alignment under prescribed gait conditions, warranting further investigation in larger cohorts.
Virtual surgical planning for midfacial distraction osteogenesis relies on static, bone-only assumptions that neglect callus and soft tissue biomechanics. This study presents a finite element framework quantifying these factors and proposes an exploratory Distraction Osteogenesis Complexity Score. A patient-specific model (849,921 elements) simulated 18 scenarios across Le Fort I-III osteotomies with varying callus stiffness and soft tissue conditions, quantifying rotation complexity, anterior translation gain, and strain risk. Scores ranged from 2.01 to 7.75 (mean 4.66 ± 1.98) and increased with osteotomy level, though overlap indicated level alone is insufficient. Standard planning underestimated displacement requirements by 59% for Le Fort III during early healing. Prospective clinical validation is required.
