部分半月板切除与半月板修复术后负荷再分布的实验计算验证
简介
通过高分辨率MRI构建三维有限元模型，在1000N轴向压缩载荷、15°屈膝条件下模拟完整半月板、部分切除术及修复术后胫股关节负荷再分布，并以200例患者临床数据验证。关键发现：部分切除术后平均接触应力从2.1 MPa增至5.5 MPa（+162%），接触面积减少45%；修复术仅使应力增至2.7 MPa（+28%），恢复92%接触面积。应力再分布指数（SRI）…
英文摘要
BACKGROUND: Meniscal preservation has become a central principle in contemporary knee surgery; however, the mechanical mechanisms explaining the protective effect of meniscal repair remain incompletely quantified. Finite element modeling provides a controlled platform to investigate tibiofemoral load redistribution following different meniscal interventions. METHODS: A three-dimensional finite element model of the human knee was developed from high-resolution magnetic resonance imaging and analyzed under a 1000 N axial compressive load at 15° of flexion. Three conditions were simulated under identical boundary conditions: intact meniscus, partial meniscectomy, and meniscal repair. Primary outcomes included mean tibiofemoral contact stress, contact area, and the Stress Redistribution Index (SRI). Model calibration was performed against published cadaveric pressure-mapping benchmarks. Translational validation was conducted through correlation with clinical outcomes from a retrospective cohort of 200 patients treated with either meniscectomy or meniscal repair. RESULTS: The calibrated model demonstrated strong agreement with experimental benchmarks, with a mean deviation of 4.4%. Partial meniscectomy increased mean contact stress from 2.1 MPa to 5.5 MPa (+162%) and reduced contact area by 45%. In contrast, meniscal repair limited stress increase to 2.7 MPa (+28%) and restored 92% of the native contact area. The SRI clearly distinguished pathological overload after meniscectomy (1.62) from near-physiological conditions after repair (0.28). SRI correlated inversely with International Knee Documentation Committee scores (r = -0.64, p < 0.001) and predicted radiographic degeneration with an area under the curve of 0.89. Sensitivity analyses demonstrated <8% variability across parameter perturbations. CONCLUSION: Experimentally calibrated computational modeling reliably reproduces tibiofemoral load redistribution after meniscal surgery. Partial meniscectomy generates substantial stress amplification and loss of load-bearing surface, whereas meniscal repair restores near-physiological stress distribution. These findings provide quantitative mechanobiological evidence supporting meniscal preservation and introduce the Stress Redistribution Index as a reproducible metric for evaluating the mechanical consequences of meniscal interventions. LEVEL OF EVIDENCE: III.