In order to be able to ascertain the position of the bone in the body without
complicated procedures in a process for the preoperative determination of the positioning
data of endoprosthetic parts of a central joint relative to the bones forming the
central joint, a respective outer articular point is determined by way of movement
of the bones about a respective outer joint which is located at the end of the
two bones facing away from the central joint. An articular point is determined
for each of the two bones in the area of the central joint, and a direction characteristic
for each of these bones is determined by way of a straight-line connection of the
two articular points obtained in this manner for the two bones. The orientation
of the endoprosthetic parts relative to this characteristic direction is then determined.
Apparatus for carrying out the process is also provided.
