The invention is related to an implant, in particular a bone replacement implant for insertion into a bone cavity, or an intervertebral implant for insertion between two adjacent vertebral bodies of a human or animal spine. The implant can be brought from a normal position, in which the implant encompasses a maximum total volume, into an insertion position, in which the implant encompasses an insertion volume, which is smaller than the maximum total volume. Moreover, the implant has a plurality of cavities in fluidic connection with one another, and a net volume encompassed in the normal position by the plurality of cavities in fluidic connection with one another is smaller than the maximum total volume, which allows insertion of the implant through as small as possible an opening in a human or animal body while maintaining a high inherent stability.