Abstract: The invention relates to a system and a method for the generation of 3D images of a moving joint (1). A rotational X-ray device (10) generates projections of said joint from different directions while the simultaneous periodic movement of the joint (1) is recorded by a monitoring device (20). The generated X-ray projections are then classified according to the phase of joint movement to which they belong, and 3D images are reconstructed from X-ray projections of each class. Thus a 3D movie of the joint movement can be produced and shown on a monitor. The monitoring device (20) may particularly be realized by an apparatus that allows the forced movement of the joint (1) in synchronization with the generation of X-ray projections.