[A study on knee joint geometry in Chinese: significance to prosthesis design]

This study for the first time provided the geometric parameters of knee joints in Chinese, which are indispensable for the design of domestic knee prosthesis. Thirty five items, including linear, radial and angular measurements, were taken from 105 cadaver knees and knee X-ray films of 100 subjects. The method and calculation for proper correction of the X-ray image magnification and joint cartilage space was established. Correlation between the X-ray correction coefficients and the body weight was found to exist, and it formed the basis for individualized correction of X ray measurements. Statistical analysis revealed that most of the linear and radial measurements were highly related while the angular measurements were independent of others. Principal component analysis showed that the width of femoral condyle might be taken as the leading index in determining the dimension of the knee, and regression functions were established. Multivariate discriminate functions could aid the selection of knee prosthesis.