Experimental computational validation of load redistribution after partial meniscectomy and meniscal repair.

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. 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. 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. 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. III.