Abstract:

Objective　In the present study we compared the morphological parameters of distal femurs with the relevant parameters of knee prostheses, intending to obtain data for better-fit prosthesis design.　Methods　(1) One hundred adult femur samples from South China (left 51, right 49) with no evident bony defect are selected and photographed. (2) The magnification is corrected according to the photographed scale. Data of measured femoral mechanical axis lengths, angles between mechanical axis/anatomical axis, transverse diameters of the condyles, transverse diameters of distal condylar osteotomic surfaces, anteroposterior diameters of the medial and lateral condyles were obtained. (3) Meanwhile, the widths between the internal and external condylar, heights of the anterior and posterior condyles of the prostheses (both domestic and imported including Zimmer NexGen LPS, Stryker Scrorpio NRG Knee-Flexed, United-U1 and GKPS) were measured.　Results　(1) The average distal femoral transverse diameter was (7.60±0.60) cm; the average height of the lateral condyles was (5.90±0.76) cm; the average height of the medial condyles was (5.73±0.74) cm. No evident relativity existed e between these data. (2)The osteotomic lengths of the prostheses from all four brands fitted Chinese people’s distal femur. By comparing the ostotomic heights of anterior condyles and the heights of anterior prosthetic condyle, a coverage rate of 14%~21% was obtained which fell within the range of tolerance. Similarly, we got a coverage rate of only 24%~55% posteriorly.　Conclusions　Since the morphological data of Chinese people’s distal femur are dispersive, individualized replacement is required. The parameters of prostheses do not completely match the morphology of distal fumurs of Chinese people.

Key words:  Prosthesis, Distal femur, Knee, Measurement