[Cementless hip prosthesis design: a basic study and analysis of the proximal femur in normal Japanese people].

Using CT images the proximal part of 50 femora was morphologically analysed in 28 normal Japanese adults. The purpose was to determine the normal stem size and shape in order to manufacture an artificial hip joint. The results were as follows: 1) The periosteal shape and the size of the normal femur were proportional. 2) The endosteal shape and the size of the normal femur were less proportional than the periosteal shape and size. 3) The endosteal width 20 mm distal from the lesser trochanter of the normal femur was 18.2 +/- 2.7 mm. 4) The femoral head offset of the normal femur was 41.8 +/- 4.8 mm. 5) The taper angle was 4.9 degrees on average, but the tapering of the proximal medullary canal was different from the tapering of the distal medullary canal.