抄録
Twenty joints of 11 patients using the Yoshino/Shoji total knee prosthesis were studied. We attempted to eliminate the error arising from individual differences, differences in the size, shape and rotation of the knee joint, and so on. For this purpose three points of the prosthesis were selected to obtain data on. This was input to a computer in order to separate the data for rotation accompanying flexion, and then the instant-center, the PAL-curve and the patella curve were investigated. X-rays of the knees were taken at 0, 30, 60, 90 and 120 degrees of flexion.
All of the knee joints showed polycentric movement. The instant center seemed to drop to a lower point upon flexion, but was not displaced very much to the posterior except in the case of sitting with one's legs under one, Japanese-style. The PAL curve and patella curve were smooth, indicating a smooth action of the knee joint. No definite tendency could be identified in regards to rotation.
