Three-dimensional Measurement Of Distal Femur And The Improvement Analysis Of Sex-difference Femoral Prosthesis

SectionⅠSexual difference of the distal femur in the design of knee prosthesisObjective To measure the anatomic parameters of the distal femur in total knee arthroplasty(TKA),discuss difference between the gender and the design of the femoral prosthesis.Methods 80 nomal knees of Chinese adults(male 40,female 40,age:18-72 years) examined by MSCT scanning and 0.625mm-gap three-dimensional reconstruction of the distal femur was performed on GE Advantage workstation.Then, a procedure of imagine was taken on the Geomagic Studio system,the height of the femur intercondyles and width of the femur through the transepicondylar line were measured.The height of the medial condylar and the lateral condylar,plus the anterior process of the medial and lateral trochleas were recorded.All the data was grouped and a comparison was preformed by gender.Results The parameters of the male femur were bigger than those of the women, including the height of the femur intercondyles and width of the femur through the transepicondylar line,the height of the condylars and the anterior process of trochleas (P＜0.001).Moreover,there was a difference of the ratio of the mediallateral diameter and anteroposterior diameter between genders.Conclusion There were certain anatomy differences in the distal femur between male and female.The authors suggested that the femoral prosthesis be design by genders to ensure a good outcome in TKA. SectionⅡMeasurement of the rotational alignment of the distal femur with 3-dimensional CTObjective To measure the included angle between the surgical transepicondylar axis(STEA) and the posterior condylar line(PCL),compared with the included angle between the femoral anteroposterior line(APL) and PCL,discuss the value of STEA, APL,and PCL as rotational alignment landmarks of the distal femur in total knee arthroplasty(TKA).Methods 80 nomal knees of Chinese adults(male 40,female 40,age:18-72 years) examined by MSCT scanning and 0.625mm-gap three-dimensional reconstruction of the distal femur was performed on GE Advantage workstation.Then, the included angle between the perpendicular line of APL and the PCL,noted as APA, together with the posterior condylar angles(PCA) between STEA and PCL were measured and compared.Results PCA:male 3.21°±1.35°(1.15°～5.92°),female 3.60°±1.40°(0.84°～5.76°); APA:male 3.17°±1.62°(0.87°～5.73°),female 3.66°±1.58°(1.34°～6.05°)。There was no significant difference between these two angles.However,sexual difference was found at PCA together with APA.These two angles showed wide variations considering their relatively small means.Conclusion Some difference and variations were found between males and females,It was not accurate to determinate the rotational alignment of the femoral component using PCL as the only landmark.The authors suggested that use APL and STEA and other means as mutiple checking the rotational alignment of the femoral component to ensure a proper rotational alignment in most TKA.The PCA were measured preoperation with MSCT would improve the accuration of the rotational alignment of the femoral prosthesis.