[Observation of prosthesis movement after implantation of the bipolar artificial femoral head].

The follow-up results of the movement of two components of hip prosthesis in 30 cases at different times after implantation of bipolar artificial femoral head were reported in this paper. It was demonstrated that the motion at both bearing surfaces in all cases was present 3 months-3 years after operation, and the motion range was not reduced with time. Therefore, the movement of bipolar artificial femoral head could be maintained within at least 3 years after implantation.