Riqi Chen, Jianxing Zhang, Kunsheng Jiang
Proceedings Volume Second International Conference on Photomechanics and Speckle Metrology, (1991) https://doi.org/10.1117/12.49563
In this paper, stress distribution in patella was studies by 3-D photoelastic experiments and finite element calculations. The experimental conditions were in good agreement with that of body mechanics: (1) The ratios of m. quadriceps femoris force
FQ to lig. patella force
FP were 1.03-1.42. (2) The angles between
FQ and
FP were 8.4°-18.7°. (3) The ratio of modulus of elasticity for epoxy resin and silicone rubber matched that for patella and cartilage, i.e., 145:1.
The principal stresses and their path line, normal stresses, contact stresses between patella and ossis femoris were determined in various flexion angles (15°, 30°, 45°, 60°, 75°, 90°). Two of the correlations were:
(1) Maximum principal stress in the front of patella
σ
max=35.8
Wexp(0.024α)
KPa
(2) Maximum contact stress between patella and ossis femoris
σ
max=−(6.86−0.14α+0.02α
2)
W KPa
where
W was body weight subjected by a single foot.
It was proved that the transverse break of patella resulted from the case that the principal stress in the front of patella exceeded ultimate tensile strength. And Tension Band Wiring (TBW) therapy conformed to the law of physiological stress field. A modified K-needles position in TBW therapy was suggested. These results are useful for further research of human patella mechanics and recovery therapy. No similar result has been found in American MEDLIN Data Bank.
