[Secondary dislocations after Synex Cage implantation].

For ventral instrumentation of spine fractures it is necessary to have an special implant for replacement of spine-body. Therefore we use titanium-cages, bone-cement and cortico-spongious pelvis bone. These are afflicted with a not so small morbidity. So in these days we have with the synex-cage a new allograft as a possible solution for that problem. In experimental studies it shows good stability. In the following cases we describe four cases of dislocation of the synex-cage. In one patient an operative revision was indicated. In the other cases the mobilization was to be reduced.