A medical implant includes a flexible container having two layers of flexible surrounding walls, each surrounding wall being provided with a plurality of through holes; a tubular fitting being connected to an open end of the flexible container for inserting or infusing a medical filling material into the flexible container through the tubular fitting; and a thrust part connected to the flexible surrounding walls of the flexible container and at a distal end of the flexible container. The thrust part has a receiving seat and a ring, the receiving seat having a central bore and an annular groove surrounding the central bore and opposite to the central bore, wherein a tubular surrounding wall is inserted into the ring and is folded so that the two layers of flexible surrounding walls are formed with the ring imbedded between the two layers of flexible surrounding walls, and the ring with the two layers of flexible surrounding walls are received in the annular groove and detained therein due to friction.