[The problem of the determination of the surface curvature of joints].

The description of knee joint cinematics is based on the exact analysis of condylar contours. In this paper, a function of second degree (elliptical equation) is proposed as an acceptable approximation to the solution of the problem. The contours of the femoral condyles can be looked at as composed of two different elliptical arches. These arches can be fitted with a high degree of accurateness. This method describes the condylar contour at least with the same approximation as the much more complicated calculation of STANISLAUS (1977) does. Furthermore the evolute of this curve does not show the extreme discontinuities of the evolute, determined by STANISLAUS.