Differences of knee anthropometry between Chinese and white men and women

Abstract

Whether there are differences in knee anthropometry between Asian and white knees remains unclear. Three-dimensional knee models were constructed using computed tomography or magnetic resonance imaging of healthy Chinese and white subjects. The morphologic measurements of the femur included mediolateral, anteroposterior dimensions, and aspect ratio. The tibial measurements included mediolateral, medial/lateral anteroposterior dimension, aspect ratio, and posterior slope of medial/lateral plateau. The results showed that Chinese knees were generally smaller than white knees. In addition, the femoral aspect ratio of Chinese females was significantly smaller than that of white females (1.24 ± 0.04 vs 1.28 ± 0.06). Tibial aspect ratio differences between Chinese and white males (1.82 ± 0.07 vs 1.75 ± 0.11), though significant, were likely a reflection of differences in knee size between races. These racial differences should be considered in the design of total knee arthroplasty prosthesis for Asian population.

Fig. 1

Femoral measurements. (A) Femoral bone model and its bounding box. (B) Measurements of femoral mediolateral and anteroposterior dimension (fML, fAP). Here, TEA indicates transepicondylar axis and PCT, posterior condylar tangent.

Fig. 2

Tibial measurements. (A) Tibial coordinate system. (B) Measurements of proximal tibia: tibial mediolateral (TML) size, medial/lateral plateau anteroposterior size (MAP, LAP). (C) The posterior tibial slope was defined as angle between tibial long axis and a line tangent to the articular surface of the plateau in the sagittal plane.

Fig. 3

(A) The lines representing the average values for the femoral aspect ratio showed a progressive decline in the femoral ratio with increasing fAP dimension for both races. A distinct offset between the fML/fAP ratio of Chinese and white females was noticed. (B) The morphological data showed a progressive decline in the tibial aspect ratio with increasing average tAP dimension for both races. The lines representing change in tibial aspect ratio with increasing average tAP dimension for Chinese and white males were nearly coincident.