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Abstract: Purposes: The importance of the femoral sagittal bowing on total knee arthroplasty is under-recognized. The bowing could lead to potential errors in positioning of the femoral component if it is ignored. We aimed to document the femoral sagittal bowing at different segments of the Chinese femur and to discuss the implications of this sagittal bowing on total knee arthroplasty. Methods: One hundred lateral radiographs of the entire lower limbs of 85 Chinese patients admitted for total knee arthroplasty were digitized. The radii of curvature of the intramedullary canal of the proximal, middle and distal one-third of the femora were measured. Results: The average age of the patients was 67.3 years. The radii of curvature of the proximal, middle and distal one-third of the femora were 1081.6, 926.2 and 715.1 mm, respectively. The distal one-third of the femora was significantly more bowed than the other parts of the femora (p<0.001). The distal femoral bowing was more profound in rheumatoid patients and in those with a short femur. Conclusions: The lateral contour of the Chinese femur is like a hockey stick. This exaggerated sagittal bowing in the Chinese femur can affect the final sagittal position of the femoral component and has implications for the choice of implant design. In revision setting, a long and straight press-fit stem might either endanger the anterior cortex or deflect the femoral component to an abnormally extended position. [Copyright &y& Elsevier]

Background: The restoration of normal axial alignment of the lower extremity is important to surgeons who perform reconstructive surgery of the knee. However, data on the normal alignment of the lower extremity in Chinese adults are not available.Methods: The axial alignment of the lower extremity in twenty-five adult male and twenty-five adult female volunteers of southern Chinese origin was measured on weight-bearing radiographs of the entire lower limb. The mean age was twenty-four years for the male volunteers and twenty-three years for the female volunteers. The results were compared with those of two similar studies of white volunteers in the United States.Results: The medial inclination of the tibial plateau in the Chinese subjects (mean and standard deviation, 5.4 +/- 2.5 degrees for women and 4.9 +/- 2.3 degrees for men) was greater than the commonly reported 3 degrees. The extremities of the Chinese women were found to have a mean of 2.2 +/- 2.5 degrees of varus alignment, and those of the Chinese men had a mean of 2.2 +/- 2.7 degrees of varus alignment.Conclusions: Compared with the white subjects described in the studies by Moreland et al. and Hsu et al., the Chinese subjects had significantly larger medial inclination of the knee joint (knee-joint obliquity) (p < 0.005) and the female Chinese subjects had significantly more varus alignment of the lower extremity (p < 0.025).Clinical Relevance: Five degrees of external rotation of the femoral component, instead of the commonly reported 3 degrees, may be required to obtain a rectangular flexion gap in total knee arthroplasty in Chinese patients. The racial difference in the knee-joint obliquity may contribute to the racial difference in the ratio of knee osteoarthritis to hip osteoarthritis. Additional studies are necessary to confirm this relationship. [ABSTRACT FROM AUTHOR]