Porcine growth plate experimental study and estimation of human pediatric growth plate properties.

Growth plate (GP) is a type of tissue widely found in child's immature skeleton. It may have significant influence on the overall injury pattern since it has distinguishing mechanical properties compared to the surrounding bony tissue. For more accurate material modeling and advanced pediatric human body modeling, it is imperative to investigate the material property of GPs in different loading conditions. In this study, a series of tensile and shearing experiments on porcine bone-GP-bone units were carried out. Total 113 specimens of bone-GP-bone unit from the femoral head, distal femur, and proximal tibia of four 20-weeks-old piglets were tested, under different strain rates (average 0.0053 to 1.907 s−1 for tensile tests, and 0.0085 to 3.037 s−1 for shearing tests). Randomized block ANOVA was conducted to determine the effects of anatomic region and strain rate on the material properties of GPs. It was found that, strain rate is a significant factor for modulus and ultimate stress for both tensile and shearing tests; the ultimate strains are not sensitive to the input factors in both tensile and shearing tests; the GPs at knee region could be grouped due to similar properties, but statistically different from the femoral head GP.