RESUMEN
BACKGROUND: Uncertainty of repairing articular cartilage defects is highly associated with the mechanical behaviors of the defected area, and the mechanical environment varies with the defect shape, depth and load. OBJECTIVE: To study the mechanical behaviors of articular cartilage defects under physiological load by finite element analysis. METHODS: The axisymmetric model of articular cartilage injury and repair based on transversely isotropy was established using ABAQUS software. The mechanical behaviors of the defect zone repaired with different repair shapes (cylindrical, frustum of a cone, orthorhombic prism, elliptical column) and depths of tissue-engineered cartilage under compressive load were analyzed. RESULTS AND CONCLUSION: The simulation results showed that there were significant differences in the mechanical behaviors of the defect area repaired with tissue-engineered cartilage in different shapes and depths. The stress concentration was the most obvious at the middle-layer defect repair, and the stress distribution was more reasonable at the deep (whole) layer defect repair. Furthermore, the distribution of the stress field and the liquid flow field at the cylinder-shaped tissue-engineered cartilage repair was the closest to the normal cartilage. That is to say, the tissue-engineered cartilage in cylinder or frustum-cone shape is recommended to repair cartilage defect. Importantly, the middle-layer repair is inadvisable.